InspectAPedia® FREE Encyclopedia of Building & Environmental Construction, Diagnosis, Maintenance & Repair |
Question? Just ask us! InspectAPedia
|
Structural Wood Timber or Beam Damage Assessment
How experts assess the structural integrity of wood framing or wood timbers on site using micro-drilling
- POST a QUESTION or COMMENT about methods used in testing structural wood members for damage or decay & the role of micro-drilling tests for in-situ evaluation of structural wood beams, timbers, or other framing members in buildings..
Test methods for determining the soundness of wood structural members:
This article series surveys methods used to test & evaluate the structural integrity of wood-framed buildings where focus is on the condition of structural wood posts, beams and other framing members. We discuss the problems surrounding hidden rot or decay, the presence or absence of moisture or other instrument-detectable clues, and the problem of subjective decisions to replace or not-replace suspect wood structural members. Page top image of micro-drilling, USDA FPL [20].
This article compares using micro-drilling with other methods to screen both standing trees and wood structural elements for hidden damage.
The original authors, Probett et als., propose a technique to provide objective pass-fail data on the condition of in-situ but suspect structural wood using micro drilling to examine wood density. This service uses timber resistance drill technology to profile variations in timber density associated with timber decay. The work is done on site and the results are instant.
This technology is objective and evidential in nature and provides assessment as to whether wood is significantly decayed, suspect or suitable for retention.
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?
Survey & Evaluation of Methods Used for Structural Wood Timber or Beam Assessment
Paul Probett, Clinton Craig, Blake Probett, Incodo Forensic Building Specialists [1]
This article series on methods for assessing structural wood rot & damage is adapted & expanded from the author's "An Introduction to Micro-Drilling Technology for N. Z. Structural Timber Assessment" and is used with permission. We [DF] have added comments, some illustrations, and additional article citations.
At the references section we include a link to the original article as well as contact information for the authors and Incodo Ltd., a Tauranga, New Zealand forensic engineering firm.
[Click to enlarge any image or illustration]
Introduction: A Brief History of Methods Used for Standing Trees & Wood Timber Assessment
A variety of tools and methods for assessing the condition of standing trees as well as the structural integrity of in-use wood timbers & beams has been in use for decades.
Several methods for obtaining drill samples or core samples from standing trees have long been in use by agencies such as the U.S. Forest Service and agencies in other parts of the world as part of evaluating the condition of standing timber and forests. [16]
In addition a variety of other methods such as ultrasound, stress waves, electrical resistance testing, mechanical coring or boring, visual inspection, and even a simple plastic hammer have been used to evaluate possible decay or insect damage in both trees and other exposed, accessible wood structural elements.
Methods used initially to evaluate standing timbers were quite naturally expanded to permit assessment of the structural integrity and condition of key wood structural members that are completely exposed and thus readily accessible, such as timber-constructed bridges, bridge pilings, telephone poles, railroad ties, as well as engineered lumber such as block-laminated timbers. [2][3][4][5][6][7][8][9][10]and [19][20][21][22][23]
The presence of those tools and methods for testing exposed timbers suggested possible applications in the evaluation of buildings and other structures in which their structural wood members may be partly or even completely hidden by finish materials.
More recently, Bohumil Kasal & Thomas Tannert have led research on the design of microdrilling methods and on the reliability of such tests in predicting the actual bending or breaking strength of structural wood members.
It was Kasal who developed recent technology of taking micro specimens of wood that in turn might be used to obtain direct measurements of the modulus of elasticity and strength of wood (in the area tested).
A direct measurement of the tension properties of wood along the wood fibers permits bending strength evaluation - important because bending strength is a key property in evaluating the structural integrity of a wood beam. Kasal's significant observation was that
... tensile strength has been related to bending strength and is considered to be approximately equal. Tensil properties have a poor correlation with compression properties therefore tensile strength can not be estimated using information attained with the core drilling technique. Specimens can however be extracted to evaluate the tensile properties of in situ members with the technique [described by Kasal]. [5]
Here, in expansion of an original article by Probett et als [1], here we discuss the range of structural wood beam or timber assessment methods where wood beams, timbers, or other structural members are used in buildings and where there is known or suspected risk of structural damage from leaks, decay by wood rotting fungi, or damage by wood destroying insects.
Because Probett et als propose and discuss the applicability of micro-drilling test methods for assessing wood structural members in-situ with or without having to perform more extensive demolition to actually expose the members, special attention is given to this method of structural assessment of wood, including Probett et als' test protocol and progress in evaluating the efficacy of this method.
Watch Out: : Important additional research on the efficacy of microdrilling has been conducted in the U.S. by the USDA Forest Products Laboratories by Brian K. Brashaw et als using the IML RESI F300-S.
That 2005 study provides important independent experience and assessment of the micro-drilling approach to structural wood testing.
As you will read in our inserted opinions and warning remarks in the article below, wood testing equipment should not be used by itself to form conclusions about a structure. Excerpting from the Brashaw micro-drilling study conclusions:
It is crucial to use this or any nondestructive testing tool or device as part of a comprehensive condition assessment. Such an assessment should incorporate an in-depth visual inspection, knowledge of prior use of the structure, and a working knowledge of fundamental engineering properties of structural wood products.
This technique, when used in concert with visual and ultrasound techniques, would provide a very accurate description of the condition of timbers. [20]
Why perform in-situ timber or wood structural member assessment?
- The timber in many New Zealand (NZ) buildings and structures is either untreated, or exposed to conditions beyond that of deigned treatment levels. Structural damage as a result of leaky homes or premature decay or just aging and attack by bacteria, wood-rotting fungi, and insects is widespread.
- Traditional methods used to determine soundness of timber have been either invasive / destructive to envelopes and interior surfaces or based largely on visual assessments.
In situ Timber Assessment Compared with Other Current Bases for Wood Structural Member Assessment
- Current basis of most decisions to retain or replace is ‘visual and chisel’ with limited microbiological backup often from “money shot” areas.
- Replacement decisions are frequently based on a conservative approach i.e. everything within 1.0m from last decay point to be replaced – emphasis is on all degrees of decay replaced. In the absence of better information the approach is considered to have some merit
- The results tend to be subjective, rather than having been based on objective and evidential data.
These conditions result in two significant error risks:
- Failing to repair or replace structural damage that thus risks a costly or injurious building collapse
- Repairing or replacing materials that actually are serviceable, resulting in significant and unnecessary costs
In situ Timber Assessment Impact on Government Departments and Local Authorities
- Possibility that more framing than strictly necessary is being replaced – impacting on FAP contributions, and Councils in particular when FAP* not pursued.
* FAP in New Zealand refers to a weatherization Financial Assistance Package provided through the Building & Housing agency of the Ministry of Business, Innovation & Employment. More information about FAP can be found at http://www.dbh.govt.nz/fap - Evidence provided by claimant in disputes tends to be opinion based and hard to challenge.
- Degree of remediation design is determined by early report snapshot findings and assumptions. This tends to lock works into a specific approach – with little opportunity for reclads to be lessened to targeted repairs or partial reclads.*
- The current absence of a widely available cost effective non-destructive in situ test methodology for timber structural element assessment has limited options for remediation.
* Note Incodo is the original authors' forensic consulting firm. Incodo’s niche is providing building forensic assistance and inspection technology to government departments, consultants and others. Incodo does not undertake remediation project management, remedial design, prepurchase or similar work.
Similarly
InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.
Current In-situ Wood Beam, Timber, or other Wood Framing Member Structural Condition Assessment Methods
Current choices for assessing the structural integrity of wood timbers, beams, or other framing members include the following:
- WOOD BEAM VISUAL INSPECTION
- WOOD BEAM MICROBIOLOGICAL ASSESSMENT
- WOOD BEAM FRACTOMETER TESTING
- WOOD BEAM PILODYN TESTING
- WOOD BEAM MICRO-DRILLING ASSESSMENT
- WOOD BEAM ROT ASSESS: MOISTURE METERS
- WOOD BEAM ROT ASSESS: THERMOGRAPHY
Each of these approaches to detecting wood beam rot and assessing its extent and its impact on the condition and serviceability of the wood member being examined is discussed and compared in the article segments listed above.
In 2013 Probett et als. presented an update on the status of micro-drilling for wood timber assessment at the U.S. FPL Wisconsin conference: 18th International Nondestructive Testing and Evaluation of Wood Symposium, as we cite below. Significant in Mr. Probett's remarks is
The main advantage of this integration is that when microdrilling and Fractometer testing are done closely together on the same plane of a piece of timber the resultant graphic profiles are very similar so we have two very different test methods crosschecking each other – the key inference is that microdrills are profiling, but not measuring compressive strength parallel to grain, but a digital Fractometer can supply actual compressive strength measurements. [1a][1b][1c]
- Paul Probett, Clinton Craig, Blake Probett, "In Situ Structural Timber Strength Measurement Advances Using Qualitive Resistography and Quantitive Resisto-Fractometry" [Power Point Presentation] [1.7MB file], Paul Probett Clinton Craig Blake Probett INCODO Ltd, Tauranga, New Zealand, mail2us@incodo.co.nz, Presentation, U.S. Forest Service Conference, Madison Wisconsin, September 2013.
- Paul S. E. Probett, Clinton S. Craig, Blake In Situ Structural Timber Strength Measurement Advances Using Qualitative Resistography and Quantitive Resisto-FractometryJ. Probett, "" [USFPL paper, 730KB], Paul S. E. Probett MIFPI, AsocRICS, MBOINZ, MNZIBS, NZCB. Clinton S. Craig Blake J. Probett
INCODO Ltd, Tauranga, New Zealand, mail2us@incodo.co.nz, 18th International Nondestructive Testing
and Evaluation of Wood Symposium - Madison, WI Sept 2013, http://www.forestprod.org/symposium2013/,
Abstract
In situ and on site evaluation of timber used for structural purposes has largely been based on methodologies that give qualitive assessments that describe condition aspects, rather than providing measurable “strength” data. This is largely due to the absence of site-friendly equipment and processes that provide the various “strength” values engineers need for meaningful structural evaluation.
Even when such methodologies are used, sample size, the degree of destructive investigation and the difficulties in quickly relating ultimate values to yield strength and/or to various local or international code requirements present issues.
This document describes a paired methodology based on electronic resistography, used alone and in concert with incremental core type fractometry coupled by using software that permits a high degree of integration of results.
This is acknowledged to be a starter paper with limitations, based on preliminary and limited research undertaken in house by a very small company, in a remote corner of the globe, undertaken by field technicians looking for solutions to a real experienced problem. It highlights, arguably, a novel direction in this area whereby specific strength characteristics of wooden structural elements can be determined on site.
Largely it identifies tools and methodologies with a strong emphasis on site applications. Keywords: digital Resistograph, digital Fractometer, fractometry, resisto-fractometry, control tests, yield strength, Woodchecker, in situ, on-site, timber strength.
Additional Wood Decay or Damage Testing Instruments / Methods
Bob Monk, USDA Forest Service, discussed the use of various types of equipment capable of detecting decay in standing trees - the epitome of in-situ testing. Monk described and tested an extensive list of tools and methods for assessing the condition of trees, possibly also used for structural wood member evaluation. Monk's USDA article expands upon the types of options and test instrument applications discussed here.
The following table of tree decay detection equipment is adapted from Mr. Monk's USDA article [16] - DF
Table of Tree Decay Detection Equipment |
|||
|---|---|---|---|
| Equipment Type & Basic Properties | Wood Test Tool Name | Wood Test Tool Cost $USD | Manufacturer / Source |
Ultrasonic wood decay detection A sound wave is transmitted through the wood to a receiver; decayed wood slows the stress-wave signal. Stress waves vary by wood species. This approach permits multiple readings (for free-standing readily-accessible timbers or of course, for trees) thus permitting a 2-D map of the extent and location of wood decay. Limited to 1m of thickness; errors arise if sensors not properly placed. Early decay hard to spot. |
Arborsonic Decay Detector | $3,000. | Fujikura Europe, England |
| James "V" Meter | $2,650. | James Instruments, Chicago, IL | |
| Sylvatest | n/a | Sandes SA, Switzerland | |
| FAKOPP Ultrasonic Timer | $2,580. | FAKOPP Ent., Hungary | |
| Picus Sonic Tomograph (12 sensors + software) |
$18,000. | Fujikura Europe, England | |
Stress Wave Timer wood decay detection Similar to Ultrasonic method above, using a lower frequency signal generated by a tap-hammer. Can handle larger diameter trees than ultrasonic. Similar limitations + wood decay type impacts detection: brown-rot fungi damage easier to detect than white-rot fungi damage. May not detect some types of decay. |
Metriguard Model 239A | $5,375. | Metriguard, Pullman, WA |
| FAKOPP Microsecond Timer | $1,970. | FAKOPP Ent., Hungary | |
| FAKOPP 2D Microsecond Timer 6,8,16-channel versions | $4,820 - $11,390 | FAKOPP Ent., Hungary | |
| IML Impulse Hammer | $2,000. | IML, Germany | |
Microdrill wood decay detection A small 2-3mm probe-drill up to 1m in length penetrates the wood using a constant, measured force. The force required for the drill to penetrate is measured and graphed. Information is limited to the area immediately surrounding the drill probe. Cannot detect early stages of wood decay. The drill opening may spread decay or invite new decay. Units with a flexible probe can present deflection errors. Longer probes add significant cost. |
SIBTEC Digital microProbe basic kit + Field Printer |
$7,000. + $1,600 |
Sibert Technology, England |
| IML Resistograph F-series (300 - 500 mm) + w/electronic unit |
$3,800 - $4,600. + $2,000 |
IML, Germany Note: USDA FPL Study [20] found 25 -100% - Sound Wood |
|
| IML Resistograph - 2012 model | Comment: Resitogrpah's new drill (the PD) is substantially different from the one used as the basis of the 2005 article referred to. That model was (apparently) based on an attachment fitted to a battery drill and drill penetration speed and rotation speed were linked mechanically. The new drill has independent computer control for penetration depth rate and rotational speed is set – not subject to how hard the operator squeezes the trigger. The embedded firmware is also programmable to detect cavities and other anomalies such as splits and checks AND ignore defects that the operator adjusts settings for. We have also developed a report template ( word with xl spreadsheet embedded ) and are using Dell tablets with WIN 7 so that results are wirelessly sent from the drill and the report is prepared as investigation proceeds. Either we preload elevations for onsite mark-up of test areas or take a photo with the tablet and mark-up on the photo we embed in the report. - P.P. |
||
| Other Micro-drilling resistance tool suppliers | Tree Solutions, Seattle, Washington SIBTEC Scientific, DmP (Digital microProbe) (United Kingdom) Resistograph™, Frank Rinn, Heidelberg, Germany. |
||
Electrical Resistance wood decay detection A 2.38mm dia. drilled hole receives an 8" - 12" long sensing probe. Decaying wood cells release metal ions that change wood resistivity. Detects decay immediately adjacent to the test hole. This method can detect early stages of decay not detected by micro-drilling. Variations in wood moisture (season for living trees, building conditions for timbers) affect individual readings - possibly compensated for by taking comparative readings at other locations in the same timber. Borings may invite or spread decay. Other less invasive wood resistivity measurement methods are available (Larsson et als). |
Shigometer | $1,700. | Osmose Wood Preserving, Buffalo, NY |
| Vitalometer | France | ||
Mechanical wood decay detection A very sharp core cutting tool removes a wood sample then measured on a stiffness/breaking-strength scale. The result is compared with a data for wood species. (Not all species provided) Data only pertains to area immediately adjacent to the test opening. Multiple borings may be needed. Studies found this tool provided a sensitive method for both white & brown rot fungal damage. Borings may invite or spread decay. |
Fractometer I Fractometer II Fractometer Electric |
$1,000. $2,000. $4,000. |
IML Germany |
Mechanical wood decay detection A long thin probe is inserted into a pre-drilled hole in the wood / tree. The insertion process uses a self-firing spring-loaded punch to progress into the opening. The number of "punches" measures wood density and condition. Properly-sized drill hole is critical for accurate measurement. Data only pertains to area immediately adjacent to the test opening. Multiple borings may be needed. Borings may invite or spread decay. |
Portable Compression Meter | n/a | N/A |
Visual wood decay detection Can include visual examination of wood taken by a core sampler. |
Increment Borer | $200. - $500. | Several |
Manual wood decay detection Portable drill and long thin 9mm bit used by an expert can quickly detect decay by noting resistance to drilling, discoloration of wood in the drill bit flutes, even sense of smell. Multiple borings may be needed. Borings may invite or spread decay. |
Plastic Mallet Portable drill & common bit |
$ 10. $50. |
Various |
| Wood or Tree Test Instrument Manufacturer Contacts | |||
| Fujikura Europe | http://www.fujikura.co.uk/ | ||
| James Instruments | http://www.ndtjames.com/ultrasonic.html | ||
| Fakopp Ent | http://www.fakopp.com/main.htm | ||
| Sylvatest | http://www.cbs-cbt.com/TECH/index_s_en.html | ||
| Metriguard | http://www.metriguard.com/metprod.htm | ||
| IML | http://www.imlusa.com/index.php | ||
| Sibert Technology | http://www.sibtec.com/digitalmicroprobe.html | ||
| Osmose Wood Preserving | http://www.osmose.com/utilities/products/accessories/ | ||
Notes to the table above
Adapted from Evaluation of Decay Detection Equipment in Standing Trees, Bob Monk, USDA Forest Service [16]
Mr. Monk's comments include the following qualifications about the equipment in this list:
More sophisticated devices such as X-ray, gamma ray tomography, magnetic resonance imaging, and thermal imaging are limited in use because of cost and practicality of field use. Some of these latter devices may have more practicality with evaluation of logs rather than standing trees.
There is a large amount of information available about individual pieces or types of equipment. There is also some information comparing some of the devices. Some information is in formal reports and some is more anecdotal, some is by the manufacturers of the equipment (need to be careful not to put too much weight on their claims). So far no report has been found that compares all of the equipment. Much of the work has been done in Europe (England and Germany mainly) and that is where much of the equipment is manufactured.
The original authors' article without the expanded discussion added here can be seen at An Introduction to Micro-Drilling Technology for N. Z. Structural Timber Assessment. [PDF]
Additional comments, illustrations, and technical citations addressing wood structure testing technologies have been added. We and the original authors invite and will reply to reader questions and comments using the comments box found at the end of this article. Initial technical review completed 8/6/201
Wood Structure Assessment Associations & Key References
- APA – The Engineered Wood Association,
7011 S. 19th Street, Tacoma, WA 98466-5333
Main: (253) 565-6600
Product support: (253) 620-7400 Website: https://www.apawood.org/
The American Wood Protection Association (AWPA) is a non-profit organization which promulgates voluntary wood preservation standards. - APA - The Engineered Wood Association [older Website: www.pacificwoodlaminates.com ], 7011 So. 19th St., PO Box 11700, Tacoma WA 98411-0700, Tel: 253-565-7265. APA provides an HDO/MDO Plywood Product Guide that offers details about these products., provides
an HDO/MDO Plywood Product Guide [PDF] that offers details about these products. Product support help desk: 253-620-7400.
Email the APA at help@apawood.org. Web search 09/13/2010, original source: http://www.pacificwoodlaminates.com/img/PDFs/PlywoodGuide.pdf - ASCE, American Society of Civil Engineers, and the Structural Engineering Institute, Tel: (800) 548-ASCE (2723)
+1 (703) 295-6300 Website: https://www.asce.org/structural-engineering/structural-engineering-institute/
Good luck finding a mailing address at this annoying website with cookies warning overlays. - ASHI, American Society of Home Inspectors, Website: https://www.homeinspector.org/
- AWPA,. American Wood Protection Association, P.O. Box 361784 Birmingham, AL 35236-1784 USA Tel: +1-205-733-4077
- IABSE,
International Association for Bridge and Structural Engineering Jungholzstrasse 28
8050 Zurich
SWITZERLAND
Phone: +4143 443 97 65
Email: secretariat@iabse.org
Excerpt:
The International Association for Bridge and Structural Engineering (IABSE) is a scientific / technical Association comprising members in 100 countries and counting 55 National Groups worldwide. Founded in 1929 it has its seat in Zurich, Switzerland. The President of IABSE (2019-2023) is Yaojun Ge, China. - IASE, Indian Association of Structural Engineers, Website: https://www.iastructe.co.in/
- NCSEA, National Council of Structural Engineers Associations, 20 N. SWacker Dr., Suite 750., Chicago IL 60606 USA Tel: 312-649-4600 Website: http://www.ncsea.com/
- NHLA, National Hardwood Lumber Association, Post Office Box 34518 Memphis, TN 38184 (901) 377-1818 info@nhla.com Website: https://www.nhla.com/
- SLMA, Southeastern Lumber Manufacturers Association, Timber Products Inspection, 200 Greencastle Road Tyrone, Georgia 30290 (770) 631-6701
- TRADA, Assessment and Repair of Structural Timber, BM TRADA
Chiltern House Site, Stocking Ln, Hughenden Valley, High Wycombe HP14 4ND, United Kingdom Tel: 01494 569601
Website Excerpt:
TRADA (The Timber Research and Development Association) is an international membership organisation dedicated to inspiring and informing best practice design, specification and use of wood in the built environment and related fields. - USDA, POST-FIRE ASSESSMENT of STRUCTURAL WOOD MEMBERS [PDF] United States Department of Agriculture, US Forest Products Lab., retrieved 2020/01/16 original source:
- USDA, WOOD and TIMBER CONDITION ASSESSMENT MANUAL [PDF] 2nd Ed. United States Department of Agriculture, US Forest Products Lab., retrieved 2020/01/16 original source: https://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr234.pdf
- WWPA, Western Wood Products Association, 1500 SW First Ave., STE 870 Portland, OR 97201 Phone: 503-224-3930 Fax: 503-224-3935 Email: info@wwpa.org Website: https://www.wwpa.org/
- Also see the detailed citations inReferences or Citations on this page.
...
Reader Comments, Questions & Answers About The Article Above
Below you will find questions and answers previously posted on this page at its page bottom reader comment box.
Reader Q&A - also see RECOMMENDED ARTICLES & FAQs
Question:
I was looking through your wood inspection articles but was wondering if there was an engineering association for wood inspection guides that you would also recommend. - Anonymous by private email 2020/01/16
Reply:
There are probably several useful associations for wood structure inspection depending on the specific situation; bridge inspections, dock and pier inspections, retaining walls at waterways, timberframe, engineered wood products, fire damage assessment of wood structures, wood preservation, wood structure rehabilitation, use of "synethtic" or plastic or composite wood products, wood scaffolding, etc.
Separate from but overlapping such special interest areas are civil engineering and structural engineering fields both of whom have sub-specialties in wood structure assessment, and for in-service field defect detection and initial assessment, the better home inspectors are intimately familiar with wood structure issues, particularly around wood frame homes and decks.
All of those groups and their associations conduct regular training and seminars and conferences.
At WOOD STRUCTURE ASSESSMENT - home organize our articles on the topic.
...
Continue reading at WOOD BEAM VISUAL INSPECTION or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.
Or see these
Wood Structure Testing Articles
- CRACKS CHECKS SPLITS in BEAMS, LOGS & POSTS
- DEFLECTION in WOOD BEAMS ROOFS FLOORS
- INSECT INFESTATION / DAMAGE - home
- MERULIPORIA HOUSE EATING FUNGUS
- TERMITE IDENTIFICATION & CONTROL
- WOOD STRUCTURE ASSESSMENT - home
- CRACKS CHECKS SPLITS in BEAMS, LOGS & POSTS
- INSECT INFESTATION / DAMAGE - home
- INSECT DAMAGE PREVENTION
- MERULIPORIA FUNGUS DAMAGE
- ROT, TIMBER FRAME
- ROT TYPES, BROWN SOFT WHITE
- ROT, TIMBER ASSESSMENT
- SPLITS & CRACKS in STRUCTURAL WOOD BEAMS
- STRUCTURAL DAMAGE PROBING
- TABLE of TREE DECAY DETECTION EQUIPMENT
- WOOD BEAM VISUAL INSPECTION
- WOOD BEAM MICROBIOLOGICAL ASSESSMENT
- WOOD BEAM FRACTOMETER TESTING
- WOOD BEAM PILODYN TESTING
- WOOD BEAM MICRO-DRILLING ASSESSMENT
- WOOD BEAM MICRO-DRILLING PROCEDURES
- WOOD BEAM MICRO-DRILLING EFFECTIVENESS
- WOOD BEAM ROT ASSESS: MOISTURE METERS
- WOOD BEAM ROT ASSESS: THERMOGRAPHY
Suggested citation for this web page
WOOD STRUCTURE ASSESSMENT at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.
Or see this
INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING STRUCTURES
Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia
Ask a Question or Search InspectApedia
Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.
Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca
Citations & References
In addition to any citations in the article above, a full list is available on request.
- Dietsch, Philipp, and Heinrich Kreuzinger. "Guideline on the assessment of timber structures: Summary." Engineering structures 33, no. 11 (2011): 2983-2986.
- Green, David W., and Roland Hernandez. "Codes and standards for structural wood products and their use in the United States." In Proceedings of the Forest Products Study Group workshop: held at the Forest Products Society annual meeting, June 23, 1998, Merida, Yucatan, Mexico.[Madison, Wis.]: Forest Products Society, c2000.: p. 3-16: ill., map. 1998.
- [1] Paul Probett, Clinton Craig, Blake Probett, "An Introduction to Micro-Drilling Technology for N. Z. Structural Timber Assessment", Incodo Ltd, 4/511 Cameron Rd, Tauranga NZ, article adapted by InspectAPedia with permission, August 2012. Contact the authors by Email: Paul Probett, mail2us@incodo.co.nz , Tel: 027 28 000 36 (Mobile) Website: https://www.incodo.co.nz/ [Copy of this article on file as Microdrilling_Assessment_Incodo.pdf]
Quoting from the Incodo website the company describes its services:
- Incodo Forensic Building Pathology:
The Forensic Building Pathology division provides evidence in report form to government agencies, consultancy firms, lawyers and others, when truly independent analysis based on comprehensive testing is required. Incodo arguably has the largest, most up-to-date and comprehensive range of building investigation equipment available and has developed unique methodologies particularly in the field of non-destructive testing for leaking structures. - Incodo In situ Timber Assessment:
The in-situ Timber Assessment division provides a service whereby technicians use state-of-the-art timber resistance drill technology to profile variations in timber density associated with timber decay.
The work is done on site and the results are instant.
This technology is objective and evidential in nature and provides assessment as to whether wood is significantly decayed, suspect or suitable for retention. The technology has particular application in locating and assessing hidden decay.
- Incodo Forensic Building Pathology:
- [1a] Paul Probett to Daniel Friedman, personal communication, 10/8/2013
- [1b] Paul Probett, Clinton Craig, Blake Probett, "In Situ Structural Timber Strength Measurement Advances Using Qualitive Resistography and Quantitive Resisto-Fractometry" [Power Point Presentation] [1.7MB file], Paul Probett Clinton Craig Blake Probett INCODO Ltd, Tauranga, New Zealand, mail2us@incodo.co.nz, Presentation, U.S. Forest Service Conference, Madison Wisconsin, September 2013.
- [1c] Paul S. E. Probett, Clinton S. Craig, Blake J. Probett, In Situ Structural Timber Strength Measurement Advances Using Qualitative Resistography and Quantitive Resisto-Fractometry" [USFPL paper, 730KB], Paul S. E. Probett MIFPI, AsocRICS, MBOINZ, MNZIBS, NZCB. Clinton S. Craig Blake J. Probett
INCODO Ltd, Tauranga, New Zealand, mail2us@incodo.co.nz, 18th International Nondestructive Testing
and Evaluation of Wood Symposium - Madison, WI Sept 2013, http://www.forestprod.org/symposium2013/,
Abstract
In situ and on site evaluation of timber used for structural purposes has largely been based on methodologies that give qualitive assessments that describe condition aspects, rather than providing measurable “strength” data. This is largely due to the absence of site-friendly equipment and processes that provide the various “strength” values engineers need for meaningful structural evaluation. Even when such methodologies are used, sample size, the degree of destructive investigation and the difficulties in quickly relating ultimate values to yield strength and/or to various local or international code requirements present issues. This document describes a paired methodology based on electronic resistography, used alone and in concert with incremental core type fractometry coupled by using software that permits a high degree of integration of results.
This is acknowledged to be a starter paper with limitations, based on preliminary and limited research undertaken in house by a very small company, in a remote corner of the globe, undertaken by field technicians looking for solutions to a real experienced problem. It highlights, arguably, a novel direction in this area whereby specific strength characteristics of wooden structural elements can be determined on site. Largely it identifies tools and methodologies with a strong emphasis on site applications. Keywords: digital Resistograph, digital Fractometer, fractometry, resisto-fractometry, control tests, yield strength, Woodchecker, in situ, on-site, timber strength. - [2] Thomas Tannert, Andreas Muller, Mareike Vogel, "Applications and limitations of NDT: a timber bridge case study", NDTCE’09, Non-Destructive Testing in Civil Engineering
Nantes, France, June 30th – July 3rd, 2009, web search 8/3/2012, original source: http://www.ndt.net/article/ndtce2009/papers/144.pdf [copy on file as Tannert_Timber_Test_144.pdf]
Abstract
The applications and limitations of different non-destructive and semi-destructive techniques to evaluate the structural integrity of timber members in a pedestrian bridge are presented as a case study. Sophisticated assessment tools are required to detect hidden damages in timber structures: for example stress-wave techniques are used to evaluate the modulus of elasticity of bending members and resistance to drilling is used to gain knowledge of areas of changed density due to insect or moisture induced damages. Reliably relating the gathered data to the structural integrity of the structure is a complex issue.
Bending members and connection details of a decommissioned timber bridge were evaluated using non destructive assessment tools. Eventually these parts were tested destructively to assess their remaining modulus of elasticity and load bearing capacity. The need for improvements in the current practice is highlighted by comparing the results from the non-destructive, semidestructive and destructive tests. - [3] Bohumil Kasal, Thomas Tannert, "RILEM Technical Committee on In Situ Assessment of Structural Timber", Bohumil Kasal et al., 2010, Advanced Materials Research, 133-134, 271,
Abstract: Timber is an intriguing structural material and the only one that is truly renewable. Being biodegradable, hygroscopic and non-isotropic, it presents special challenges when assessing its integrity in structures. The presented paper outlines the major issues related to in-situ evaluation of structural timber and summarizes the work of the RILEM Technical Committee 215-AST “In-situ assessment of structural timber”. The committee was established in 2005 to bring together leading scientists and practitioners in the field of evaluation of timber in existing structures. Timber structures have been investigated for decades using numerous techniques that have been either developed specifically for the material or were transferred from other fields of investigation. A state-of-the-art report describing existing and emerging technologies and methods was prepared by the RILEM committee. The report describes the principles, the applications and the limitations of major evaluation techniques for in-situ assessment of timber. A brief discussion of codes standards and future research needs shows that much needs to be done in this area. As a present activity, harmonized test procedure recommendations are being prepared that will provide the engineering community with valuable guidance when evaluating timber structures. - [4] Bohumil Kasal & Thomas Tannert (Editors), State of the Art Reports: In Situ Assessment of Structural Timber, ISBN 978-94-007-0559-3, Rilem 2010
- [5] Bohumil Kasal, Tension Micro Specimens,
In Situ Assessment of Structural Timber
RILEM State of the Art Reports, 2011, Volume 7, 75-80, DOI: 10.1007/978-94-007-0560-9_8, [excepts chapter 7 on file: Tension Micro-Specimens, as Kasal_Testing.pdf]
Abstract The principle of this method is extracting triangular specimens (about 5 mm equal-sides triangle) along the length of the member. Small-kerf circular saw with a fixture attached to the surface of the member is used to extract the specimens. Specimens are then glued to the test blocks and tested in tension. The method gives direct values of tensile modulus of elasticity and strength for clear wood. The values are local and pertain to the tested area and surface.
[From chapter 7.1 Background: This method was developed by Kasal and is based on direct measurement of tension properties along fibers. Bending strength evaluation is an important aspect of in situ evaluation of timber members as it is one of the predominant modes of loading, but estimates of the bending properties in situ can present a challenge.
With information on the member's tensile properties, bending strength estimates can be made; tensile strength has been related to bending strength and is considered to be approximately equal. Tensile properties have a poor correlation with compression properties therefore tensile strength can not be estimated using information attained with the core drilling technique. Specimens can however be extracted to evaluate the tensile properties of in situ members with the technique described in the following sections....'] - [Also] Kasal B, Anthony R: Advances in in-situ evaluation of timber structures. Progress in Structural Eng and Materials. 6(2):94-103, 2004.
- [6] Thomas Tannert, Andreas Müller, Mareike Vogel, "in-situ assessment, hot spots, moisture content, block-laminated timber", ICTB 2010, Bern University of Applied Sciences. ISBN 978 8251 926805, in-situ assessment, hot spots, moisture content, block laminated timber,
Abstract:
Timber has been a structural material for bridges for centuries and numerous examples throughout the world demonstrate its durability. But timber is biodegradable and hygroscopic and regular inspections are recommended to determine the condition of the structure. This paper reports on the structural health monitoring of timber bridges in general and the long term moisture measurement inside block-laminated timber elements of several traffic bridges in specific.
Presently there is no reported scientific information available on the long-term moisture behaviour and the resulting moisture induced stresses and dimensional changes of block-laminated timber elements. The paper reports on the monitoring of the moisture content of a block-laminated timber bridge.
[References 7-13 below are cited from this document] - Thomasson, Gary L., Joseph Capizzi, F. Dost, J. Morrell, and D. Miller. "Wood preservation and wood products treatment: training manual." (2006). [PDF]
- [7] Wilkinson K, Thambiratnam D, Ferreira L. Non Destructive Testing of Timber Bridge Girders. In Proceedings Int. Conf. on Structural Condition Assessment, Monitoring and Improvement, Perth, Australia, 2005.
- [8] Kasal B, Anthony R: Advances in in-situ evaluation of timber structures. Progress in Structural Eng and Materials. 6(2):94-103, 2004.
- [9] Gerold M. Bloc-Glued Laminated decks for timber bridges. Structural engineering international, 12(3): 214–217, 2002.
- [10] Graham T. Overview of non-destructive evaluation technologies. In Proceedings of the Nondestructive Evaluation of Aging Bridges and Highways, Ed by S. Chose, 1995.
- [11] Duwadi SR, Ritter MA. An Overview of the Wood in Transportation Program in the United States, In Proceedings 5th World Conference on Timber Engineering, Montreux, Switzerland, 1998.
- [12] Rinn F, Schweingruber FH, Schär E. Resistograph and X-Ray Density Charts of Wood. Comparative Evaluation of Drill resistance Profiles and X-Ray Density Charts of Different Wood Species. Holzforschung 50:303-311, 1996.
- [13] Brashaw B, Vatalaro RJ, Wacker JP and RJ Ross. Condition Assessment of Timber Bridges: 1. Evaluation of a Micro-Drilling Tool. Gen. Tech. Rep. FPL-GTR-159. Forest Products Laboratory Madison, WI. 2005.
- [14 Simpson W. Drying and Control of Moisture Content and Dimensional Changes. Chapter 12, Wood handbook - wood as an engineering material. General Technical Report FPL–GTR– 113. Forest Products Laboratory, WI, 1999.
- [15] "Fractometer Print Manual", IML Instrumenta Mechanik Labor System GmbH Großer Stadtacker 2 69168 Wiesloch • Germany, 02-2008, web search 8/4/12, original source: http://www.imlusa.com/Fractometer_Print_eng_web_A4.pdf [Copy on file as Fractometer_Print_eng.pdf]
- [16] Bob Monk, "Evaluation of Decay Detection Equipment in Standing Trees", USDA Forest Service, web search 8/4/12, original source http://www.fs.fed.us/eng/techdev/IM/tree_decay/tree_decay_detect_equip.shtml [Copy on file as Monk_Tree_Deday_Detection.pdf] Introduction - quoting:
A project was proposed to test and compare several of the devices that are able, to some degree, to detect decay in trees. Decay in trees is directly related to the hazards that they present. However, detection of decay does not necessarily mean that a tree is hazardous. The identified devices can be used to determine what decay is present. It is still necessary to use professional experience and sound judgment to decide if a tree actually poses a hazard. General guides or "rules of thumb" can also be used, such as Guidance notes from the Minnesota Department of Natural Resources and the USDA Forest Service, 1996 that suggests a 25 mm ring of sound wood is required for every 150 mm of stem diameter at any point on the stem. If the proportion of decayed wood to sound wood exceeds this level then action may need to be taken to minimize the hazard posed by the tree (Lawday and Hodges, 2000). [Additional selected citations from this article are below]- [16a] Larsson, B.; Bengtsson, B.; and Gustafsson, M. 2004. Nondestructive Detection of Decay in Living Trees. Tree Physiology. 24: 853-858
- [16b] Moore, W. 1999. The Combined Use of the Resistograph and the Shigometer for the Accurate Mapping and Diagnosis of the Internal Condition of woody Support Organs of Trees. Arboriculture Journal. 23: 273-287
- [16c] Nicolotti, G.; Socco, L.V.; Martinis, R.; Godio, A.; and Sambuelli, L. 2003. Application and Comparison of Three Tomographic Techniques for Detection of Decay in Trees. Journal of Arboriculture. 29(2): 66-77
- [16d] Seavey, R.; and Larson, T. 2002. Inspection of Timber Bridges. Minnesota Department of Transportation Technical Report MN/RC-2002-34. St. Paul, MN. 43 p.
- [16e] Wang, X.; Divos, F.; Pilon, C.; Brashaw, B.K.; Ross, R.J.; and Pellerin, R.F. 2004. Assessment of Decay in Standing Timber Using Stress Wave Timing Nondestructive Evaluation Tools: A Guide for Use and Interpretation. Gen. Tech. Rep. FPL-GTR-147. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 11 p.
- [17] Pilodyn Wood Tester, USA / Canadian Source: Intech-NDE, 6211 Roper Road
Edmonton, Alberta
T6B 3G6, Tel: 1 888-576-7756 or Intech-NDE, 140 - 8851 Beckwith Road
Richmond, B.C., Tel: 1 800-677-8884, or USA Tel: 800-297-3208, Website: http://www.intechnde.com, web search 8/4/12, original source: http://www.corvib.com/pilodyn/ Quoting:
Pilodyn is an easy-to-use wood testing instrument which is suitable for trees, railway ties and utility poles. The Pilodyn wood tester (Hylec Controls) is described by and currently available in North America from InTech/NDE U.S. Tel: 905-716-5604 / 800-297-3208, or Email: bnadeau@intechnde.com - [18] Pilodyn Wood Tester, Hylec Controls, available in Australia from Ferret http://www.ferret.com.au/n/Pilodyn-wood-density-meter-from-Hylec-n852069 - Quoting:
Pilodyn, available from Hylec Controls , was developed to determine the density and strength of dead and living wood. Invisible soft rot can be detected rapidly and objectively in an easy non-destructiveway and the reduction in strength associated with it can be determined. This can be of vital importance in the case of wooden playground structures,climbing frames and telephone masts.
With PILODYN 6J Forestversion the density of the wood is determined on living trees. The damage is so little that the tree suffers no harm and the testing method is regarded as non-destructive.
Testing procedure: The testing procedure is very simple: The tester is loaded with the ramrod and then pressed firmly onto the tet surface. The impact pin is shot into the wood by pressing the trigger cover. The depth of penetrationcan be read straightaway in mm on the scale mounted on the tester.
Typical applications of the Pilodon:
Testing the stability of wooden structures on playgrounds, detection of soft rot
Testing the strength on wooden telephone masts, detection of soft rot
When thinning out: sorting out trees with undesirable density of the wood
Early detection of diseases: periodic measurement detects unnatural changes in the wood density
Comparison of the location-dependent density to determine the optimal location for the respective tree species
Establishing productivity with respect to density for the same tree species and similar location properties for culture purposes Testing and sorting of cut wood into timber classes - [19] Hylec Controls, 8 Melissa Street AUBURN NSW 2144 AUSTRALIA, Tel: 1300 522 004, Email: sales@hyleccontrols.com.au, http://www.ferret.com.au/c/Hylec-Controls
- [20] Brashaw, Brian K.; Vatalaro, Robert J.; Wacker, James P.; Ross, Robert J. 2005. "Condition Assessment of Timber Bridges: 1. Evaluation of a Micro-Drilling Resistance Tool" Gen. Tech. Rep. FPL-GTR-159. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 8 p., web search 8/5/2012, original source: http://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr159.pdf [copy on file as Micro_Drill_Study_USDA_fpl_gtr159.pdf] This publication is also available from the U.S. FPL at www.fpl.fs.fed.us
Abstract:
The research presented in this report was conducted to evaluate the accuracy and reliability of a commercially available micro-drilling resistance device, the IML RESI F300-S (Instrument Mechanic Labor, Inc., Kennesaw, Georgia), in locating deteriorated areas in timber bridge members. The device records drilling resistance as a function of drilling depth, which allows the operator to assess the location of deterioration in the member cross section.
Bridge components containing different levels of natural decay were used as test specimens in this study. The IML RESI F300-S was first used to assess decay in the timber bridge specimens. The specimens were then sawn along their length into slabs to expose their interior condition. The interior faces of these slabs were inspected visually and with a stress-wave probe to confirm if deterioration was present. On the basis of these tests, we conclude that this micro-drilling device accurately determines if deterioration is present at the point at which the test is performed. Keywords: timber, bridges, inspection, drilling resistance, nondestructive evaluation
Excerpt from the study's conclusions:
Based on our tests, we offer the following comments about the accuracy of using the IML RESI F300-S for locating deterioration in bridge timbers:
1. The tool is accurate at determining the presence of decay in timber bridge specimens. However, these data are limited to the drilling location.
2. The tool can precisely locate an internal defect (decay pocket, check, or split) within the member’s cross section. This can be advantageous for condition assessment and load rating purposes.
3. Decay indices were developed for Douglas-fir timbers as follows: sound, >25% resistance; moderate decay, 10–25%; and advanced or severe decay, 0–10%.
One drawback is that multiple, time-consuming drilling would be required to map the area and extent of the decay in the other plane. Another possible drawback is the potential to spread the decay to sound areas within a timber or to sound timbers by multiple use of a contaminated drill bit. Routine cleaning of drill bits, or replacement with a new one, would greatly reduce this potential drawback.
It is crucial to use this or any nondestructive testing tool or device as part of a comprehensive condition assessment. Such an assessment should incorporate an in-depth visual inspection, knowledge of prior use of the structure, and a working knowledge of fundamental engineering properties of structural wood products. This technique, when used in concert with visual and ultrasound techniques, would provide a very accurate description of the condition of timbers. - [21] Brashaw, B.K.; Vatalaro, R.J.; Erickson, J.R.; Forsman, J.W.; Ross, R.J. 2004. Final Report: A Study of Technologies to Locate Decayed Timber Bridge Members. Project No. 187-6456, NRRI/TR-2004-06. Duluth, MN: UM-Duluth, Natural Resources Research Institute.
- [22] Brashaw, B.K.; Vatalaro, R.J.; Ross, R.J.; Wacker, J.P. 2005. Condition Assessment of Timber Bridges: 2. Evaluation of Several Commercially Available Stress Wave/Ultrasonic Tools. Gen. Tech. Rep. FPL-GTR-160. Madison, WI: USDA Forest Service, Forest Products Laboratory.
- Nosker, Thomas J., Richard W. Renfree, and K. E. Van Ness. "The use of commingled plastic lumber as construction materials." [PDF] In TECHNICAL PAPERS OF THE ANNUAL TECHNICAL CONFERENCE-SOCIETY OF PLASTICS ENGINEERS INCORPORATED, pp. 3216-3216. SOCIETY OF PLASTICS ENGINEERS INC, 1993.
- [23] Ross, R.J.; Brashaw, B.K.; Wang, X.; White, R.H.; Pellerin, R.F. 2004. Wood and Timber Condition Assessment Manual Madison, WI: Forest Products Society. 74 p.
- [24] Troltech GMBH & Co. KG. Deutchland, Grebbener Str. 7, D-52525 Heinsberg, Deutchland, produces the Trotec T2000, Tel: 02452 962-450, International: +49 2452 962-450, Email: online@trotec.de, Website: http://www.trotec.de/, Web page for the Troltec T2000: http://www.trotec.de/en/product-catalog/measuring-instruments/multi-function/t2000/
- [25] Paul Probett, Incodo, Ltd., "Thermal Imaging and Building Surveying / Inspection" 2008, Incodo Ltd, 4/511 Cameron Rd, Tauranga NZ, article adapted by InspectAPedia with permission, August 2012. Contact the authors by Email: Paul Probett, mail2us@incodo.co.nz , Tel: 027 28 000 36 (Mobile) Website: https://www.incodo.co.nz/ [Copy of this article on file as Thermal Imaging NDT Presentation 2008.ppt ]
- Steve Bliss's Building Advisor at buildingadvisor.com helps homeowners & contractors plan & complete successful building & remodeling projects: buying land, site work, building design, cost estimating, materials & components, & project management through complete construction. Email: info@buildingadvisor.com
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education. Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com - Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
- Decks and Porches, the JLC Guide to, Best Practices for Outdoor Spaces, Steve Bliss (Editor), The Journal of Light Construction, Williston VT, 2010 ISBN 10: 1-928580-42-4, ISBN 13: 978-1-928580-42-3, available from Amazon.com
- The Journal of Light Construction has generously given reprint permission to InspectAPedia.com for certain articles found at this website. All rights and contents to those materials are ©Journal of Light Construction and may not be reproduced in any form.
- Allen, Edward and Joseph Iano. Fundamentals of Building Construction: Fourth Edition. Hoboken: John Wiley & Sons, 2004. pg. 91 [LVL lumber]
- Building Failures, Diagnosis & Avoidance, 2d Ed., W.H. Ransom, E.& F. Spon, New York, 1987 ISBN 0-419-14270-3
- Building Pathology, Deterioration, Diagnostics, and Intervention, Samuel Y. Harris, P.E., AIA, Esq., ISBN 0-471-33172-4, John Wiley & Sons, 2001 [General building science-DF] ISBN-10: 0471331724 ISBN-13: 978-0471331728
- Building Pathology: Principles and Practice, David Watt, Wiley-Blackwell; 2 edition (March 7, 2008) ISBN-10: 1405161035 ISBN-13: 978-1405161039
- CRAWL SPACE MOISTURE CONTROL [PDF] U.S. Department of Energy
- Design of Wood Structures - ASD, Donald E. Breyer, Kenneth Fridley, Kelly Cobeen, David Pollock, McGraw Hill, 2003, ISBN-10: 0071379320, ISBN-13: 978-0071379328
This book is an update of a long-established text dating from at least 1988 (DJF); Quoting:
This book is gives a good grasp of seismic design for wood structures. Many of the examples especially near the end are good practice for the California PE Special Seismic Exam design questions. It gives a good grasp of how seismic forces move through a building and how to calculate those forces at various locations.
THE CLASSIC TEXT ON WOOD DESIGN UPDATED TO INCLUDE THE LATEST CODES AND DATA. Reflects the most recent provisions of the 2003 International Building Code and 2001 National Design Specification for Wood Construction. Continuing the sterling standard set by earlier editions, this indispensable reference clearly explains the best wood design techniques for the safe handling of gravity and lateral loads. Carefully revised and updated to include the new 2003 International Building Code, ASCE 7-02 Minimum Design Loads for Buildings and Other Structures, the 2001 National Design Specification for Wood Construction, and the most recent Allowable Stress Design. - Diagnosing & Repairing House Structure Problems, Edgar O. Seaquist, McGraw Hill, 1980 ISBN 0-07-056013-7 (obsolete, incomplete, missing most diagnosis steps, but very good reading; out of print but used copies are available at Amazon.com, and reprints are available from some inspection tool suppliers). Ed Seaquist was among the first speakers invited to a series of educational conferences organized by D Friedman for ASHI, the American Society of Home Inspectors, where the topic of inspecting the in-service condition of building structures was first addressed.
- Domestic Building Surveys, Andrew R. Williams, Kindle book, Amazon.com
- Defects and Deterioration in Buildings: A Practical Guide to the Science and Technology of Material Failure, Barry Richardson, Spon Press; 2d Ed (2001), ISBN-10: 041925210X, ISBN-13: 978-0419252108. Quoting:
A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome. Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level. - Guide to Domestic Building Surveys, Jack Bower, Butterworth Architecture, London, 1988, ISBN 0-408-50000 X
- Historic Preservation Technology: A Primer, Robert A. Young, Wiley (March 21, 2008) ISBN-10: 0471788368 ISBN-13: 978-0471788362
- Manual for the Inspection of Residential Wood Decks and Balconies, by Cheryl Anderson, Frank Woeste (Forest Products Society), & Joseph Loferski, October 2003, ISBN-13: 978-1892529343,
- Microllam Laminated Veneer Lumber (LVL) and/or Parallam Parallel Strand Lumber (PSL) MSDS Material Safety Data Sheet, courtesy of Weyerhaeuser Company, PO Box 9777, Federal Way, WA 98063-9777 Tel: 253-924-3865
- Log Homes: Log Home Design, U.S. Department of Energy
- In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested
CONTINUE READING or RECOMMENDED ARTICLES.
- Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: info@carsondunlop.com. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The HOME REFERENCE BOOK - the Encyclopedia of Homes and to use illustrations from The ILLUSTRATED HOME .
Carson Dunlop Associates provides extensive home inspection education and report writing material. In gratitude we provide links to tsome Carson Dunlop Associates products and services.
 | HOME | ABOUT | ASK a QUESTION | CONTACT | CONTENT USE POLICY | DESCRIPTION | POLICIES | PRIVACY | |
| © 2024 - 1985 Publisher InspectApedia.com - Daniel Friedman | |||||||||