Fire Damage to Buildings vs Mold Damage
InspectAPedia® -
Photos & discussion of fire damage vs mold damage
Issues with seller failure to disclose prior fire damage
Issues with possible hidden mold damage in purchased home
Questions & Answers on Distinguishing Between Fire & Mold Stains in Buildings
This article discusses how fire damage and mold damage might be recognized in a building and how we might distinguish between black stains and white sealant paints used in both fire damage repair and mold remediation projects.
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers nor with topics or services discussed at this website.
Comparing Fire Damage to Buildings with Mold Damage
Our page top photo shows fire damage in the attic of a New York home.
Structural Repairs Following a Fire Get Confused With Venting Trouble and Mold Contamination
Question:
I found your website and found it extremely helpful. However I have a very particular situation and would like to have your suggestions and comments. Here are the series of facts leading to this e-mail to you.
Type of house: 1983 Canadian style with drooping front roof purchased January 2011
Information from seller: 2006 inside renovations (kitchen, living room and bathroom) 2008 new roof – completely redone. When asked if there had ever been water damage, problems or fires in the past the seller answered no to all questions.
Recent leak history: March 2011 – lots of snow and then + 5 degrees Celsius- our roof started leaking and water was leaking in our front door frame.
We went up in the attack and discovered that the air system did not have the protection to prevent fine snow to enter the roof area. There was a line of snow in the middle which probably melted.
After discovering this, I decided to have an engineer who work in construction problems, etc.
3rd April 2011 – Engineer visits and says there is an air problem in the roof top and all the wood seems to have been painted over and there seems to be dark black marks under the paint.
He also says the front part of the drooping roof does not have sufficient space to let air circulate and that this probably caused the water to run down the door frame inside. We are still waiting for the official report.
9th April 2011 – The seller informed us that there was a fire at the construction stage of the house 28 years ago and that is what the black is all about in the roof...They painted over it to seal in the smell.
So we have two different diagnoses of these black and painted areas: mold or fire. What do I do now?
How can I check if I actually have a mold problem ?
How do I fix the black fire appearance or mold traces in my attic ?
How can I fix the insulation problem in my roof (cathedral part of the roof ? - C. & R.
Reply:
A competent onsite inspection by an expert - a real one who knows both mold and fire damage - usually finds additional clues that help accurately diagnose a problem.
Also your photos are less than one one thousandth of what I'd look at if I were inspecting the building, so any opinion I give is of necessity incomplete..
That said, here are some things to consider:
By your account the seller was not forthcoming about the prior fire. However if proper inspection, assessment and repairs were made, the house may not be facing a costly fire-damage repair at all. Nevertheless, there might be some residual impact on the property value at re-sale time.
It is common practice to paint over fire damaged wood provided the wood is not structurally compromised - to seal in odors. Painting over fire blackened wood is not harmful.
It is possible to distinguish between mold and fire damage: A careful inspection of the painted areas and the surrounding material can often sort out the difference between fire-damaged surfaces that were painted and mold-contaminated surfaces that were coated, as I elaborate below.
Fires do create a secondary mold risk at a property: extinguishing a fire, presuming it was extinguished with water, dumps a lot of water into and through the structure. That process, when the fire is in the upper part of the structure in particular, sends a lot of water through lower ceilings and walls. Unless all of those areas are opened, gutted, dried, a future mold problem in those areas is a high risk.
Your photo of blocked soffits and where no white paint appears (photo at left) and no black marks on sheathing also shows a sister rafter at the right side of the photo - possibly part of a post-fire roof repair/replacement, or sometimes this is done to straighten a sagging roof.
This photo shows the soffit virtually blocked, black stained fiberglass insulation in the eaves in a pattern that could be due to air movement/air leaks, and thermal tracking. The engineer is correct that roof venting is improper and blocked, risking a moisture and mold problem.
Your next two photos (below) how white-painted surfaces low at the house eaves on sheathing and some rafters, more sistered rafters, Some of the roof sheathing appears to be plank or T&G boards, other, plywood.
In the photo showing a white-painted sistered rafter under roof sheathing and diagonal bracing (below-right, looks much like a repaired truss), the paint pattern on the upper truss chord and absence of paint and absence of mold on the roof planks that rest atop the sistered/repaired roof truss form a compelling argument that the paint was applied relating to a fire not mold - mold wouldn't grow on just the truss side and not on the adjoining wood roof decking. An exception would be if the roof decking was replaced and the old, repaired truss left in place. Usually plank roof decking is older than plywood roof decking.
Your last photo shows insulation pulled back and what looks like blackened ceiling, studs, and sheathing. I cannot tell from the photo where in the structure this is, if it is in a moisture path, if there is corroborating indication of surrounding moisture staining on insulation, rusted nails, etc. or if it is left-over charring from the fire.
Given that the (apparently) vertical wall in this last photo is black with something, an astute home inspector who had access to this area during a pre-purchase home inspection would be expected to observe and comment on that anomaly and to warn you of its possible consequences.
Some Specific Suggestions for Handling Mold & Fire Traces in a Home
How can I check if I actually have a mold problem in this house ?
An inspection by a expert who is familiar with mold contamination should include a look at the history of the extent of demolition and repair after the fire as well as looking carefully at the water path through the building.
In addition to visual inspection for mold or mold-suspect materials, it makes sense to sample some surface areas especially ones where your engineer thinks that there is a mold problem . Surface sampling is in order; if you like you can also screen the building for mold using air and dust sampling but the visual inspection and surface samples are most important.
How do I fix the black fire appearance or mold traces in my attic ?
Use sealant paints that are approved for fire restoration to cover or paint over unsightly fire blackened members, presuming that an expert has assured you that no further structural repairs are needed.
How can I fix the insulation problem in my roof (cathedral part of the roof ?
Attic ventilation, to work effectively, needs continuous air intake at the eaves and outlet at the ridge. Insulation & ventilation contractors use baffles to provide an air path in through vented soffits and add a ridge vent. See our article series on attic ventilation beginning at ROOF VENTILATION SPECIFICATIONS
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
Brick Development Association, The Building Centre, 26 Store Street, London, WC1E 7BT, England, U.K., Tel: 020 7323 7030, Email: brick@brick.org.uk
Brick Industry Association, 1850 Centennial Park Drive, Suite 301, Reston, VA 20191
Phone: 703.620.0010 Fax: 703.620.3928.
Canada Masonry Centre, 360 Superior Blvd., Mississauga ON Canada L5T 2N7. Tel: (905) 564-6622. Offers the CMCA Textbook of Canadian Masonry.
"Concrete Slab Finishes and the Use of the F-number System", Matthew Stuart, P.E., S.E., F.ASCE, online course at www.pdhonline.org/courses/s130/s130.htm
Sal Alfano - Editor, Journal of Light Construction*
Thanks to Alan Carson, Carson Dunlop, Associates, Toronto, for technical critique and some of the foundation inspection photographs cited in these articles
Arlene Puentes, ASHI, October Home Inspections - (845) 216-7833 - Kingston NY
Greg Robi, Magnum Piering - 800-822-7437 - National*
Dave Rathbun, P.E. - Geotech Engineering - 904-622-2424 FL*
Ed Seaquist, P.E., SIE Assoc. - 301-269-1450 - National
Dave Wickersheimer, P.E. R.A. - IL, professor, school of structures division, UIUC - University of Illinois at Urbana-Champaign School of Architecture. Professor Wickersheimer specializes in structural failure investigation and repair for wood and masonry construction. * Mr. Wickersheimer's engineering consulting service can be contacted at HDC Wickersheimer Engineering Services. (3/2010)
*These reviewers have not returned comment 6/95
Superior Walls of America, Ltd, 937 East Earl Road, New Holland, PA 17557, Phone: 1-800-452-9255, Fax: 717-351-9263. Website: http://www.superiorwalls.com/ Technical support:
Ed Helderman our Codes and Standards Manager. Email: ehelderman@superiorwalls.com or 717-351-9744
Robert Hare, Director of Technical Operations, rhare@superiorwalls.com, Tel: 717.351.9735
Thanks to Robert Hare for technical critique & content suggestions for this article - August 2010
Superior Walls of America Builder Guideline Booklet MAN 42-9000 booklet, [local copy] web-search 09/01/2010 original source (indirect link): http://www.superiorwalls.com/faq.php?&answers=1&details=53
...
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop, and from the InspectAPedia bookstore. The 2010 edition of the Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Allen, Edward and Joseph Iano. Fundamentals of Building Construction: Fourth Edition. Hoboken: John Wiley & Sons, 2004. pg. 91 [LVL lumber]
APA - The Engineered Wood Association, 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 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
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.
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.
Georgia-Pacific Building Products, 133 Peachtree Street NE, Atlanta, GA 30303. Telephone:
(404) 652-4000 , Wood Products: 800-284-5347. Gypsum Products: 800-255-6119. LVL lumber: GP-LAM, web search 09/14/2010, original source: http://www.gp.com/build/product.aspx?pid=1392
"Avoiding Foundation Failures," Robert Marshall, Journal of Light Construction, July, 1996 (Highly recommend this article-DF)
"A Foundation for Unstable Soils," Harris Hyman, P.E., Journal of Light Construction, May 1995
"Backfilling Basics," Buck Bartley, Journal of Light Construction, October 1994
"Inspecting Block Foundations," Donald V. Cohen, P.E., ASHI Reporter, December 1998. This article in turn cites the Fine Homebuilding article noted below.
"When Block Foundations go Bad," Fine Homebuilding, June/July 1998
Laminated Veneer Lumber, Overview of the Product, Manufacturing, Market, Department of Forest Products Marketing, wood-Based Panels Technology, Finland [PDF] web search 09/14/2010, original source: http://www.hochstrate.de/micha/finnland/reports/replvl.html
Masonry structures: The Masonry House, Home Inspection of a Masonry Building & Systems, Stephen Showalter (director, actor), DVD, Quoting: Movie Guide Experienced home inspectors and new home inspectors alike are sure to learn invaluable tips in this release designed to take viewers step-by-step through the home inspection process. In addition to being the former president of the National Association of Home Inspectors (NAHI), a longstanding member of the NAHI, the American Society of Home Inspectors (ASHI), and the Environmental Standard Organization (IESO), host Stephen Showalter has performed over 8000 building inspections - including environmental assessments. Now, the founder of a national home inspection school and inspection training curriculum shares his extensive experience in the inspection industry with everyday viewers looking to learn more about the process of evaluating homes. Topics covered in this release include: evaluation of masonry walls; detection of spalling from rebar failure; inspection of air conditioning systems; grounds and landscaping; electric systems and panel; plumbing supply and distribution; plumbing fixtures; electric furnaces; appliances; evaluation of electric water heaters; and safety techniques. Jason Buchanan --Jason Buchanan, All Movie Review
Masonry Structures: Behavior and Design, Robert G. Drysdale, Ahmid A. Hamid, Lawrie R. Baker, The Masonry Society; 2nd edition (1999), ISBN-10: 1929081014, ISBN-13: 978-1929081011
Straw Bale Home Design, U.S. Department of Energy provides information on strawbale home construction - original source at http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10350
More Straw Bale Building: A Complete Guide to Designing and Building with Straw (Mother Earth News Wiser Living Series), Chris Magwood, Peter Mack, New Society Publishers (February 1, 2005), ISBN-10: 0865715181 ISBN-13: 978-0865715189 - Quoting: Straw bale houses are easy to build, affordable, super energy efficient, environmentally friendly, attractive, and can be designed to match the builder’s personal space needs, esthetics and budget. Despite mushrooming interest in the technique, however, most straw bale books focus on “selling” the dream of straw bale building, but don’t adequately address the most critical issues faced by bale house builders. Moreover, since many developments in this field are recent, few books are completely up to date with the latest techniques. More Straw Bale Building is designed to fill this gap. A completely rewritten edition of the 20,000-copy best--selling original, it leads the potential builder through the entire process of building a bale structure, tackling all the practical issues: finding and choosing bales; developing sound building plans; roofing; electrical, plumbing, and heating systems; building code compliance; and special concerns for builders in northern climates.
Ohawa, Ontario Wood Reference Handbook, p. 166, Canadian Wood Council, 1991
Sinkholes and Sudden Land Subsidence References, Products, Consultants
"A Hole in the Ground Erupts, to Estonia's Delight", New York Times, 9 December 2008 p. 10.
History of water usage in Estonia: (5.7 MB PDF) jaagupi.parnu.ee/freshwater/doc/the_history_of_water_usage_systems_in_estonia.pdf
"Quebec Family Dies as Home Vanishes Into Crater, in Reminder of Hidden Menace", Ian Austen, New York Times, 13 May 2010 p. A8. See http://www.nytimes.com/
"Quick Clay", Wikipedia search 5/13/2010 - http://en.wikipedia.org/wiki/Quick_clay
Florida DEP - Department of Environmental Protection, & Florida Geological survey (http://www.dep.state.fl.us/geology/default.htm) on Florida sinkholes: Effects of Sinkholes on Water Conditions Hernando County, Florida, Brett Buff, GIS in Water Resources, 2008, Dr. David R. Maidment, Photos - Tom Scott, Florida Geographic Survey - Web Search 06/09/2010 - http://www.dep.state.fl.us/geology/geologictopics/jacksonsink.htm
and - http://www.dep.state.fl.us/geology/geologictopics/sinkhole.htm
also see
Lane, Ed, 1986, Karst in Florida: Florida Geological Survey Special Publication 29, 100 p.
Foundation Engineering Problems and Hazards in Karst Terranes, James P. Reger, Maryland Geological Survey, web search 06/05/2010, original source: http://www.mgs.md.gov/esic/fs/fs11.html Maryland Geological Survey, 2300 St. Paul Street, Baltimore, MD 21218
"Frost Heaving Forces in Leda Clay", Penner, E., Division of Building Research, National Research Council of Canada, Canadian Geotechnical Journal, NRC Research Press, 1970-2, Vol 7, No 1, PP 8-16, National Research Council of Canada, Accession number 1970-023601, Quoting from original source
The frost heaving forces developed under a 1 ft. (30.5 cm) diameter steel plate were measured in the field throughout one winter. The steel plate was fixed at the ground surface with a rock-anchored reaction frame. heave gauges and thermocouples were installed at various depths to determine the position and temperature of the active heaving zone. The general trend was for the surface force to increase as the winter progressed. when the frost line approached the maximum depth the force was in excess of 30,000 lb (13,608 KG). Estimates of the heaving pressure at the frost line ranged from 7 to 12 psi (0.49 to 0.84 KG/cm) square during this period. The variation of surface heaving force was closely associated with weather conditions. Warming trends resulting in a temperature increase of the frozen layer caused the forces to decline.
"Geoscape Ottowa-Gatineau Landslides", Canada Department of Natural Resources, original source http://geoscape.nrcan.gc.ca/ottawa/landslides_e.php - quoting from that source:
Leda clay slopes in the Ottawa valley are vulnerable to catastrophic landslides. More than 250 landslides, historical and ancient, large and small, have been identified within 60 km of Ottawa. Some of these landslides caused deaths, injuries, and property damage, and their impact extended far beyond the site of the original failure. In spectacular flowslides, the sediment underlying large areas of flat land adjacent to unstable slopes liquefies. The debris may flow up to several kilometres, damming rivers and causing flooding, siltation, and water-quality problems or damaging infrastructure. Geologists and geotechnical engineers can identify potential landslide areas, and appropriate land-use zoning and protective engineering works can reduce the risk to property and people.
Deposits of Leda clay, a potentially unstable material, underlie extensive areas of the Ottawa-Gatineau region. Leda clay is composed of clay- and silt-sized particles of bedrock that were finely ground by glaciers and washed into the Champlain Sea. As the particles settled through the salty water, they were attracted to one another and formed loose clusters that fell to the seafloor. The resulting sediment had a loose but strong framework that was capable of retaining a large amount of water. Following the retreat of the sea, the salts that originally contributed to the bonding of the particles were slowly removed (leached) by fresh water filtering through the ground. If sufficiently disturbed, the leached Leda clay, a weak but water-rich sediment, may liquefy and become a 'quick clay'. Trigger disturbances include river erosion, increases in pore-water pressure (especially during periods of high rainfall or rapid snowmelt), earthquakes, and human activities such as excavation
and construction.
After an initial failure removes the stiffer, weathered crust, the sensitive clay liquefies and collapses, flowing away from the scar. Failures continue in a domino-like fashion, rapidly eating back into the flat land lying behind the failed slope. The flowing mud may raft intact pieces of the stiffer surface material for great distances.
Kochanov, W. E., 1999, Sinkholes in Pennsylvania: Pennsylvania
Geological Survey, 4th ser., Educational Series 11,
33 p., 3rd printing April 2005, Pennsylvania Department of Conservation and Natural Resources / Bureau of Topographic and Geologic Survey, DCNR Educational Series 11, Pennsylvania Geological Survey, Fourth Series, Harrisburg,
1999 - web search 06/05/2010, original source: http://www.dcnr.state.pa.us/topogeo/hazards/es11.pdf - Quoting from the document introduction: The first 18 pages of this booklet contain an explanation of how sinkholes
develop. In order to tell the sinkhole story, it is important to discuss
a number of related geologic disciplines. The words used to describe sinkholes
and these disciplines may be a bit unfamiliar. However, general explanations
are given throughout the booklet to help clarify their meanings.
Key words are printed in bold type for emphasis. The more important
ones are defined in a Glossary that begins on page 29.
The remaining sections, starting with “Sinkholes in the Urban Environment”
(page 18), deal with sinkholes and their impact on our environment.
This includes recognition of subsidence features and sinkhole repair.
[1] Sarah Cervone, [web page] data from the APIRS database, Graphics by Ann Murray, Sara Reinhart and Vic Ramey, Vic Ramey is
the editor. DEP review by Jeff Schardt and Judy Ludlow. The web page is a
collaboration of the Center for Aquatic and Invasive Plants, University of Florida, and the Bureau of Invasive
Plant Management, Florida Department of Environmental Protection contact: varamey@nersp.nerdc.ufl.edu [A primary resource for this article
[2] Center for Cave and Karst Studies or the
Kentucky
Climate
Center, both at
Western
Kentucky
University
Vanity Fair - web search 06/04/2010 http://www.vanityfair.com/online/daily/2010/06/what-caused-the-guatemala-sinkhole-and-why-is-it-so-round.html
Sinkholes, Virginia Division of Mineral Resources,
Virginia Department of Mines, Minerals and Energy, www.dmme.virginia.gov Virginia Department of Mines, Minerals and Energy
Division of Mineral Resources
900 Natural Resources Drive, Suite 500
Charlottesville, VA 22903
Sales Office: (434) 951-6341 FAX : (434) 951-6365
Geologic Information: (434) 951-6342
http://www.dmme.virginia.gov/
divisionmineralresources.shtml - Web search 06/09/2010
Sink Hole & Related Engineering References
Newton, J. G., 1987, Development of sinkholes resulting from man's activities in the eastern United States: US Geological Survey Circular 968, 54 p.
Sinclair, W. C., 1982, Sinkhole development resulting from ground-water withdrawal in the Tampa Area, Florida: U.S. Geological Survey Water-Resources Investigations 81-50, 19 p.
White, W. B., 1988, Geomorphology and Hydrology of Karst Terrains: Oxford University Press, New York, 464 p.
Williams, J. H. and Vineyard, J. D., 1976, Geologic indicators of subsidence and collapse in karst terrain in Missouri: Presentation at the 55th Annual Meeting, Transportation Research Board, Washington, D.C.
Barry F. Beck, A. J. (1999). Hydrogeology and Engineering Geology of Sinkholes and Karst. Rotterdam, Netherlands: A. A. Balkema.
Beck, B. F. (2003). Sinkholes and the Engineering and Environmental Impacts of Karst. Huntsville, Alabama: The American Society of Civil Engineers.
Beck, B. F. (2005). Sinkholes and the Engineering and Envrionmental Impacts of Karst. San Antonio, Texas: The American Society of Civil Engineers.
Tony Waltham, F. B. (2005). Sinkholes and Subsidence, Karst and Cavernous Rocks in Engineering and Construction. Chichester, United Kingdom: Praxis Publishing.
Whitman D., G. T. (1999). Spatial Interrelationships Between Lake Elevations, Water Tables, and Sinkhole Occurence in Central Florida: A GIS Approach. Photogrammetric Engineering and Remote Sensing , 1169-1178.
Lincoln Log Homes Marketing, Inc., 6000 Lumber Lane, Kannapolis NC 28081 704-932-6151
Merrimac Log Homes, Henniker, NH, sells log home products, milled log home kits, log siding, and log home plans and log home construction accessories. 866-637-7462 or logs@mlhnh.com - merrimacloghomes.com
PermaChink Systems, Knoxville TN 800-548-1231 provides a range of log chinking products, coatings, and sealants for log and other wood buildings.
Mobile View
