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Insect damage or mold contamination in or on fiberboard insulating sheathing used on or in buildings:
This article discusses the occurrence of mold contamination and also insect damage on fiberboard sheathing used on roofs, walls, ceilings in buildings and on building exteriors.
This article series gives the efinition, ingredients, history, use, fire resistance & insulating properties of fiberboard sheathing. This article describes and provides photographs that aid in identifying various insulating board sheathing materials used on building walls and roofs, such as Homasote, Celotex, Insulite, and Masonite insulating board sheathing products.
Mold Growth & Wood Boring Insect Susceptibility of Fiberboard Building Insulating Sheathing Products
We do not usually find mold growth on fiberboard building insulating sheathing nor insect damage to this material. Possibly the resin binder and coating is unattractive to insects and the moisture resistance of some coatings also reduce the ease of mold growth on this material.
[Click to enlarge any image]
However in sufficiently challenging conditions such as very wet conditions or prolonged exposure to water and moisture or insects.
We have found both extensive mold growth on Homasote type insulating board (photo above, in a wet basement against a masonry wall) and evidence of insect damage to an interior wall fiberboard sheathing product, probably Beaver board or Upson board (in the attic of a leaky building, below).
At DRYWALL, FIBERBOARD, PLASTER INTERIORS we discuss the types of non-structural interior sheathing boards (plaster, gypsum board, drywall, fiberboard) that were used on building interior walls and ceilings.
Insects in fiberboard products: Reader comment: insect attack through fiber-type flooring
(Feb 27, 2013) Teresa Mietus said:
I live in a 50's home.
Termites literally built an entire empire between the top and bottom layers of a fiber type floor board.
If not for the mud tunnels, the floor would have fallen through
! What you don't see - can hurt you.
Research on Insect Damage to LDF & MDF Fiberboard Products
Indrayani, Yuliati, Dina Setyawati, Sasa Sofyan Munawar, Kenji Umemura, and Tsuyoshi Yoshimura. "Evaluation of termite resistance of medium density fiberboard (MDF) manufacture from agricultural fiber bonded with citric acid." Procedia Environmental Sciences 28 (2015): 778-782.
Kameshki, B. "Evaluation of particleboard treated with Preservation material (ACQ, and Evaluate of the durability of wood BFCA and Chlorothalonil) products against termite attack." PhD diss., University of Zabol, 2015.
Question: Question about Homasote product from 1940s. Mold problems on gypsum board exterior building sheathing?
Was there a Homasote product used in the early 1940s on the exterior of houses that looks like sheet rock? How long does this last for?
If it is still on the house, could it contain mold due to lack of sunlight?
Was there "code" at some point that would have forced individuals who were to replace vinyl siding on the house over these boards to replace with proper products after a certain date?
Thank you, K.B.C.
Reply: Properties of Homasote® type fiberboard compared with gypsum-based exterior wall & roof sheathing boards
Homasote® fiberboard sheathing is a wood fiber product, not a gypsum or plasterboard product. However there were indeed gypsum-based sheathing board products used on buildings both as wall sheathing (under siding and over studs) as well as roof sheathing.
Having inspected quite a few buildings that used this material, my OPINION is that it has proven surprisingly durable so long as it was kept dry. Wet the material can become soft, and also one might find mold growth on the paper backing of the gypsum board.
See MOLD EXPERT, WHEN TO HIRE for help in deciding if in your particular case hiring a competent professional to inspect and test the building is justified.
Requirements to Remove Old Siding & Sheathing When Re-Siding a Building?
Finally, I've not found any national building code that requires a homeowner to replace one existing siding or wall sheathing material with another. The decision on siding-over existing surfaces vs. doing a (more expensive) tear-off depends on at least these considerations:
The condition of the structure beneath the siding and sheathing. Siding and sheathing may need to be removed for structural repairs, for example.
The condition of the siding and sheathing itself: very rough siding in poor condition forms a bad base over which to install new siding materials. The installer might simply nail furring strips over the existing walls, then install the new siding to the furring, or s/he might recommend a tear-off.
Aesthetic/cosmetic concerns: when you build out a building's exterior walls with furring and new siding, the thicker wall will usually extend past existing window and door trim - giving the windows and doors a "sunken" look that you might not like. A solution is to build out the building trim at the same time.
Some builders install wood or foam backer over the existing trim and wrap the new opening in aluminum so that it projects out past the new siding.
Watch out: be careful not to add multiple vapor barriers to a building wall. Installing an air and moisture resistant vapor-permeable housewrap should be fine however, and is required by some building codes and some product manufacturers.
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 Homasote® Company, 932 Lower Ferry Road, West Trenton, NJ 08628-0240 Tel: 800-257-9491 Ext 1332, or from outside the U.S. call 609-883-3300. Website: http://www.homasote.com/ , Email: Sales@homasote.com.
Thanks to Homasote CEO Warren Flicker for technical review and comment on this article.
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: email@example.com
 Celotex Corporation, PO Box 31602, Tampa FL 33631, with offices in Atlanta, Chicago, Cincinnati, Dallas, Oakland and Philadelphia, and plants in six U.S. States is headquartered in Tampa, FL. Celotex is a national manufacturer of residential and commercial building materials. Website: www.celotex.com Tel: 800-CELOTEX
"Insulation Selector Guide", Celotex Corporation, web search 6/29/12, original source: http://www.silvercote.com/PDF/ThermaxInsulSelectorGuide.pdf, [copy on file as CelotexThermaxInsulSelectorGuide.pdf ]
"Celotex Blue Ridge Fiberboard", SturdyBrace®, produced by Blue Ridge Fiberboard Inc., 250 Celotex Dr., Danville VA 24541, product literature, web search 6/29/2012, original source: blueridgefiberboard.com/pages/sturdybrace.php, [Copy on file as Celotex_BlueRidge_SturdyBrace.pdf].
MSDS: original source: blueridgefiberboard.com/pages/sturdybrace/pdfs/SturdyBrace-msds-br.pdf
"Guide Specifications: SturdyBrace® Structural Fiberboard Wall Sheathing", 6/29/12, original source: blueridgefiberboard.com/pages/sturdybrace.php [Copy on file as SturdyBrace-guidespecs.pdf]
 Douglas Leen, Petersburg AK 99833, contributed the photograph of insulating board scraps from roof insulation removed from a building. Dr. Leen provides such a wide range of services, collectables, and historical information about the Northwest that a succinct description is difficult: flying dentist goes anywhere, antique forestry posters, historic campers, the tugboat Katahdin, in Alaska, Washington, and Wyoming. Mr. Leen can be contacted at firstname.lastname@example.org or at 907-518-0335
 Georgia Pacific: information about DensGlas gypsum board building sheathing can be found at the company's website at gp.com/build/product.aspx?pid=4674
 Pittsburgh Press, "Yesterday - in costly homes alone, Today even the simplest home can have this hidden comfort", The Pittsburgh Press, 19 April 1925, classified ads section. Web search 6/22/12, [Copy on file as Celotex_Ad_023_PP.jpg and more]
 pending research
Patents pertaining to building insulation & insulating board, Celotex & Insulating Board type products
"Sound absorbing board for walls and ceilings", Patent No. 1,554,180, issued to W.S. Trader, September 15,1925, first disclosed a wallboard constructed from "Celotex", a felted mass of strong bagasse fibers, so compacted as to be capable of use as an artificial lumber in that it can be sawed and nailed, and has sufficient strength in many cases to be substituted for lumber. That same patent mentions "Insulite", a building board made from wood pulp tailings and which likewise has a porous fibrous body portion and which is possessed of considerable strength so that the same can be nailed, etc. Celotex was preferred as an insulating material because its internal cells produce a sound-deadening insulating effect.
"Method and apparatus for drying moving material", Treadway B. Munroe et als, assigned to Dahlberg & Co., U.S. Patent No. 1,598,980, 7 September 1926, described a method and apparatus for drying sheets of artificial heat insulating lumber, known on the market as Celotex, improving the original process.
"Reenforced composition board", Treadway B. Munroe et als, U.S. Patent No. 1,578,344, 30 March 1926
"Insulating Structural Board", U.S. Patent 2,159,300, Armen H. Tashjian et als, assigned to William B. Miller, Lakewood OH, 23 May 1939, describes insulating structural boards of laminated construction for use as roof or floor slabs, and refers to "Standard insulating fiber boards, such as "Celotex", "Masonite", "Insulite", etc. that had excellent insulating properties but have relatively slight structural strength in flexure or bending under load, hence are not and cannot be used as structural slabs for load sustaining purposes, as roof or floor slabs, for example. [Adding structural strength ran into the problem of reducing the insulating value of the product.]
"Sound-absorbing chamber", Treadway B. Munroe et als, U.S. Patent No. 1,705,778, 19 March 1929 (using Celotex to construct a sound deadening chamber.
"Method of and apparatus for drying moving material", U.S. Patent 2,376,612, Carl G. Muench, New Orleans, assigned to Celotex Corporation, described a method and apparatus for drying sheets of artificial heat insulating lumber, preferably formed by the felting of bagasse fiber along with other materials necessary to make a satisfactory structural fiber board. 22 May 1945
"Sound-absorbing board for walls and ceilings," U.S. Patent 1,554,180, Sept. 15, 1925, Wilber S. Trader, assignor to Dahlberg & Company, Chicago IL. described an interior-use sound insulating product.
 "Insulite Co. v. Reserve Supply Co.," 60F.2d 433 (1932), Circuit Court of Appeals, Eighth Circuit, July 26, 1932. Web Search t/23/12. Quoting:
Rabbeted joints in material to which plaster or other material is applied are found in the Jones patent, No. 886,813. In this patent the composition is made up of plaster of paris, cement, or other like substance, combined with hair, wood fiber, sawdust, wool, wood shavings, excelsior, straw, or similar substances. The length of the lath covers three joists instead of four. The boards are arranged in staggered relation to each other and the joints are shiplapped. The specification states that after the boards or blocks are placed in position they may be covered with wallpaper or other similar material, which, of course, would include plaster.
"Machine for perforating Insulite Boards", U.S. Patent No. 1,306,283, Patented 10 June 1919, John K. Shaw, inventor from Minneapolis MN, describes improvements for machines for perforating Insulite Boards.
"Before you Build write for this mailing piece and a sample of Insulite", [advertisement], The Literary Digest, 13 September 1940.
 Museum of Fine Arts, Boston, web search 6/22/12, original source: http://cameo.mfa.org/browse/record.asp?subkey=3644 [Copy on file as MFAB_Fiberboard.pdf]
 "Separating the Fiber of Wood", A.S. Lyman, U.S. Patent No. 21,077, 3 August 1858
 Standards pertaining to fiberboard insulating sheathing:
ASTM C 208-95 (2001) – Standard Specification for Cellulosic Fiber Insulating Board. Type IV Grade 2 (Structural Wall Sheathing).
ASTM C 846-94 (2003) – Application of Cellulosic Fiber Insulating Board for Wall Sheathing.
ASTM D 1554 - Definitions of terms Relating to Wood Based Fiber and Particle Panel Materials.
ASTM E-72 (1997)- Standard Method for Conducting Strength Tests of Panels for Building Construction.
ANSI /AHA - A194.1, Cellulosic Fiberboard.
U.S. Department of Commerce: PS57-73, Cellulosic Fiber Insulating Board
A.F.A. (2003): Fiberboard Sheathing test results
 "Properties of insulating fiberboard sheathing",
Forest Products Laboratory (U.S.)
Luxford, R. F. (Ronald Floyd), 1889 (1960), original report 1955, citation:hdl.handle.net/1957/2489, web search 6/29/12, original source: http://ir.library.oregonstate.edu/xmlui/handle/1957/2489
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.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. 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 & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
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The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, 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. Field inspection worksheets are included at the back of the volume.
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