Fiberboard insulating sheathing used on or in buildings:

Definition, ingredients, history, use, fire resistance & insulating properties of fiberboard sheathing. Fiberboard was used indoors as both a finish-surface to be painted or as a base to which plaster and then paint were applied.

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.

Fiberboard Building Sheathing FAQs

These questions and answers about fiberboard sheathing, or Beaverboard®, black board, buffalo board, gray board, cane board, Celotex®, Homasote®, Insulite®, Nu-Wood® were posted originally at FIBERBOARD SHEATHING - home - so be sure to review that article too.

On 2022-10-10 by InspectApedia (mod) - how much does fiberboard weigh

@Anonymous,

The total weight depends on the size of your fiberboard panel. A 4' x 8' piece of 1" thick fiberboard weighs approx. 115 pounds.

For measuring other sizes or thicknesses, see

https://calculator.academy/medium-density-fiberboard-mdf-weight-calculator/

On 2022-10-10 by Anonymous

what does 1 inch fiberboard wiegh

On 2022-09-19 by InspectApedia-911 (mod) - how do I recognize fiberboard products

@Keisha,

Fiberboard products are quite distinctive and easy to recognize as you will see in the photos in this article series.

If your wall board actually looked like cardboard or corrugated cardboard box like material you may be surprised to learn that there were some wall panels made of that material. That was basically paper.

Of course I don't know what you have I'm just outlining what you could have.

On 2022-09-18 by Keisha

Hi: Really appreciate your site. I did something very stupid. I took down four layers of old wall paper in a house built in 1972. Underneath I found a wall that was not drywall, but almost like a cardboard material that I could peel away very easily in strips similar to craft paper.

It was rough and without thinking it out hand sanded it and created a lot of dust. Not only did I regret this later because of fire retardants and other chemicals, but I also thought of asbestos.

I'm not sure exactly what kind of "fiberboard" it is. You are so knowledge, I thought I would ask. Thanks so much.

 

On 2022-07-17 by InspectApedia-911 (mod) - Gold Bond products contain asbestos?

@Patrick,

We've researched the question of asbestos in Gold Bond products - including fiberboard sheathing (your question about asbestos in Gold Bond insulating sheathing board) and also Gold Bond ceiling tiles and Gold Bond drywall.

Please take a look at

SHEATHING, FIBERBOARD ASBESTOS CONTENT

NATIONAL GYPSUM CEILING TILES

NATIONAL GYPSUM DRYWALL ASBESTOS?

On 2022-07-17 by Patrick

Does anyone know if Gold Bond insulation board has asbestos. It looks like celotex says gold bond building products IBI rated R1.32

On 2022-05-04 by Inspectapedia Com Moderator - Fiberboard is a thin insulating sheathing not a structural component

@Tom Herman,

Thank you for a helpful question.

Fiberboard is a thin insulating sheathing. It certainly would not be adequate by itself in a cold climate. But it's commonly used as an exterior wall cladding. It's not structural.

But neither was your aluminum siding. It's perfectly adequate as a backer for vinyl siding. The structure of your home is going to depend on either plywood or diagonal bracing at least at the corners.

On 2022-05-03 by Tom Herman

Turning off aluminum siding and find this celotex blackboard underneath I am putting on vinyl siding is this blackboard sturdy enough and an r value high enough to increase the warmth of a home and being vinyl siding is being placed over top is it structurally sound?

On 2022-01-16 by Inspectapedia Com Moderator - need to have objective data not just speculation to be sure of a correct answer

@barbara smith,

Speculation on everyone's part, without objective data, such as a lab test of your materials of concern, we are left doing so much guessing that there's not much chance of a guess being correct.

On 2022-01-16 by barbara smith

@Inspectapedia Com Moderator, ok what type of fiberboard for ceilings such as brand,design,type of fiberboard has ever used asbestos in the paint coating as a fire resistant measure?

On 2022-01-15 by Inspectapedia Com Moderator

@barbara smith,

From the limited paint description we have so far, I can't offer a generic name for a paint coating on a ceiling except possibly fire retardant paint.

If I haven't made this clear before let me try again,

we are spending too much time speculating and inventing vague answers with no objective data or information information.

The result is that you can't have any confidence in anything that you conclude.

Too much speculation means too great a possibility of being wrong.

On 2022-01-15 by barbara smith

@Inspectapedia Com Moderator, ok the inspector emailed back and said its the same paint coating that was used in false drop down ceilings of commercial buildings if you would know what kind that would have been called?

On 2022-01-14 by Inspectapedia Com Moderator

@barbara smith,

It's perfectly possible that an asbestos expert has collected samples and had lab tests done that confirmed an asbestos-based paint on building materials - perhaps there as a fire resistance measure.

Such paints, if not the more fragile popcorn or textured paints, are not so soft, not friable, and thus are less of a hazard - leave alone, paint-over.

Beyond that speculation on everyone's part, without objective data, such as a lab test of your materials of concern, we are left doing so much guessing that there's not much chance of a guess being correct.

On 2022-01-14 by barbara smith

its me again,sorry to bother you so much but another asbestos inspector has answered me back and we discussed this on the phone as well but he says in old 50s and 60s mobile homes he has found asbestos in the fiberboard ceiling,not the ceiling itself but the dull white paint coating from the manufacturer,he said hes not talking about popcorn or any type of texture but the plain dull white coating applied as im getting soo confused

On 2022-01-12 by Inspectapedia Com Moderator

@barbara smith,

For clarity please read the two articles that I recommended since they offer clear answers to your concerns

On 2022-01-12 by barbara smith

ok i dont quite understand. does no mean that no its not common for a large sheet or panel to have a backing with asbestos? also is it common for the fiberboard to have asbestos adhesive?

On 2022-01-11 by Danjoefriedman (mod) - backing and mastic adhesives with asbestos

@barbara smith,

No.

Do see details at

SHEATHING, FIBERBOARD ASBESTOS CONTENT - do some wood or cellulose-based fiberboard or insulating board products contain asbestos? Maybe.

and also for a discussion of the use of asbestos in mastic adhesives see

ASBESTOS MASTIC IDENTIFICATION

On 2022-01-11 by barbara smith

Asbestos was also used in homes and buildings in the walls, floors, and ceiling. This is a mineral that is naturally occurring and made of soft and flexible fibers. In addition, it was on the paper facing and backing, and mastic adhesives for gluing tiles to the ceiling.

this perhaps may be what the inspectors were talking about with a backing and mastic adhesives.. this is referring to tiles with a backing but has it been known for a large sheet or panel to have a backing with asbestos?

also the mastic as you said it would be uncommon for fiberboard to have mastic to hold them onto ceilings.did you mean uncommon for any adhesives or asbestos containing adhesives? thanks

On 2021-04-17 by danjoefriedman (mod)

@Anonymous, you're right, it's shocking.

On 2021-04-17 by Anonymous

Y is osb 7/16 up to 40 bucks a sheet this is unreal

On 2021-01-28 by danjoefriedman (mod)

George

If you can provide me with photos (one per comment) or product specs or specific brand names that will help me research the question and to check against the R-value data we already have.

On 2021-01-28 by george adams

what are the R-Values for the fiberboard roofing panels [decking] made with glued and pressed excelsior. A lot of use in the 60s but haven't seen in years. Can't find product literature.

On 2020-12-04 by danjoefriedman (mod)

Leslie

While there may be a product with that name and spelling, like Google, I think your original specifications may themselves contain a misspelling, because there is in fact a widely used and familiar product, Plyscore .

On 2020-12-01 by Leslie

I have a 1966 home. The original specs call for 5/8" Plyscord sheathing for the roof. Every time I search for this product, Google, et al... think that it is misspelled. Regardless, does this sheathing have asbestos in it?

On 2020-03-01 by danjoefriedman (mod)

Mike:

As it will be helpful to other readers, and as its publication may prompt other readers to offer a helpful suggestion, I will include a redacted (to respect your privacy) version of our ongoing discussion about venting vs. closing and conditioning the HVAC duct utility attic in your home in our article at

HOT ROOFS in HOT HUMID CLIMATES

near the bottom of that article.

Often our published version of the question will include expanded discussion and additional references beyond this original email reply.

 

On 2019-11-19 - by (mod) -

Many coatings such as plaster or just paint were often applied directly to the fiberboard. There's no moisture barrier between the plaster and the fiberboard.

On 2019-11-19 by Barry

I'm sorry that I was not clear, so let me try to improve on that. Yes, I am planning to do this from the attic side, laying batts between the ceiling joists. And yes, I am going to seal the leaks first.

The attic has actual floor boards, pieces of which have been removed in places such as air conditioning registers, which facilitates the sealing of leaks.

By removing selected floor boards, I can gain enough access to slide in sections of insulation. I have done that in some places in the past, as other work was done, and now I am going to complete the job. Where I have done it I have used fiberglass insulation that was faced with a vapor barrier.

Of course the barrier was down towards the living area as you say, However, after reading some of the excellent information you have on this web site, I am finally realizing that I am dealing with plaster over wood ldf. This had always been a mystery to me as I cut holes for electrical boxes, etc., and finally the mystery is solved for me.

But, what I am wondering is if there might already be some sort of vapor barrier between the plaster and the fiber board, and if therefore, using faced insulation might create a vapor trap that would cause the fiberboard to become moldy or rot. It sounds like you don't think that should be a concern, but I hope my clarification will allow you to understand my question better.

On 2019-11-19 - by (mod) -

Barry

If you want to add insulation in the attic floor it's usually easiest to do that from the attic side - I'm not sure but I think you're headed that way; but if you plan to cover your ceilings with drywall (which would be a step towards meeting modern fire codes too)

AND if there is a hard-to-access-from-above attic floor, then yeah you could blow insulation in through the ceiling and then cover all that with drywall.

Flipping the project over and discussing batts installed from above, between the ceiling joists,

A vapor barrier on the WARM side - down towards heated space - is traditional good practice ... though most important is not allowing air leaks into or through the ceiling;

A vapor barrier in the right place - as I said, down at the upper side of the ceiling - avoids a moisture problem and ought not cause an issue with the fiberboard left in place;

On 2019-11-18 by Barry

My interior walls and ceilings are some unidentified ldf wood fiberboard with a layer of plaster over it. Although I know that the fiberboard provides some insulation, I want to add insulation as I can in the attic floor, probably using batts. I can get the batts in the floor by removing some of the floor boards.

i am wondering whether to use batts that are faced with a vapor barrier or if that will cause moisture to collect in and damage the fiberboard.

On 2019-08-21 - by (mod) -

We can do some scholarly research on the actual Shear strength but generally I think your experts are absolutely correct.

After all of you look at the use of fiberboard sheathing on the walls of wood frame constructed buildings you'll see that at the corners of those buildings the Builder either used let in bracing or to provide the necessary rigidity.

Most likely your experts are considering that the storm resistance and structural requirements need to be met when there is sufficient change, modification, or renovation on an existing building. I also requested how many layers you'd want to keep adding to such a roof.

On 2019-08-21 by David Breuner

HI, I have a 1957 Ranch style home with fiberboard roof panels. I do not know the brand name, but they appear to be painted white on the inside, 4'X8' panel size, and tar and gravel on top. In later years, the homeowner added 3" rigid foam insulation and then put a new tar and gravel overlay on top.

I am doing a remodel, and my architect and engineer claim that the fiberboard must be completely removed from the entire house because it has no shear strength.

That means complete tear off of the entire roof all the way to the roof beams. Big expense! My question is does the 2" - 2.5" fiber board have shear value, or is it too soft to meet code? I live in Marin County, CA. Also, there is half inch ply on top of the fiberboard, and he says that is not good enough... that there must be direct wood to wood contact to provide necessary shear strength. Thank you!

Dave
415 359 6045

On 2019-03-11 - by (mod) -

I thought you were going to install house wrap. I would run metal flashing or even at flashing tape around the openings but install the flashing tape so that it extends under rather than on top of the house wrap if the tape is not adhering securely to the house wrap itself.

On 2019-03-09 by Leo

@Leo,
Thank you very much for the reply. What sort of flashing would you use on fiberboard sheathing? Tar paper?

On 2019-03-08 - by (mod) -

Leo

You're right that stick-on or peel-and-stick membrane flashing (that makes the job wonderful) around windows and doors doesn't work well on fiberboard as it doesn't stick; in my experience it also doesn't stick well to some housewraps either - at least not always.

IN that case we run the flashing up under the housewrap over and alongside of windows and doors, then take care to bring it out atop the housewrap to direct water out of the building wrap as appropriate.

On 2019-03-08 by Leo

Hello. I am doing a pretty extensive remodel to my 80s house, which has fiberboard sheathing. The sheathing appears to be about 1/2" thick. There is no flashing around the existing windows or doors. I plan to replace the windows and the siding. The new windows are flanged, just like the originals, but unlike the originals, I want to flash the openings

. I also want to install a house wrap of some kind. But I'm not sure what sort of flashing to use with this sheathing, and I'm not quite sure how to install house wrap over it, as the sheathing has no nail holding ability.

Does anyone know, will self-adhesive flashing tapes adhere to fiberboard sheathing? And how do you install house wrap over it? Will nailing the house wrap to only the studs be adequate? I've contemplated removing the sheathing, or sheathing over it with plywood, but I am curious to hear what others think. Thanks for any thoughts.

On 2018-09-24 by (mod) - repair damaged grooved fiberboard or beaverboard ceiling

I think what I would do particularly since the material is so inexpensive, would be to look for modern fiberboard panel and using very sharp knife and straight edge cut matching grooves. I wouldn't try using a router as I think that it'll blow dust all over the place without making a smooth enough cut.

Keep in mind that I fiber board panels on walls and ceilings in the interior of a modern home and are not likely to meet modern building fire codes. So there's a fire safety issue as well. unfortunately the solution is to cover the existing material with a layer of drywall

On 2018-09-24 by Steve

Thank you. Yes, it is fiberboard, and called beaver board by some. Would you have access to any info about the grooves?

Due to water damage i have lost two ornate ceilings. My guess is that I will not be able to duplicate these panels. Thank you for your response

On 2018-09-20 by (mod) - fiberboard panels that had grooves or other designs

Steve

If I assume from the fact that your question is posted on a page about fiberboard sheathing that you are ceiling material is in fact a fiberboard product, that I can answer that some of the manufacturers sold tooled fiberboard panels that had grooves or other designs cut into them.

Some Builders may have in fact cut panels to set designs in the field as well.

On 2018-09-19 by Steve

This stuff covers the walls and ceilings of my house. It is scored with different designs on the ceilings in all of the rooms. I can not find any info on how these patterns were created, and if they can be reproduced.

On 2018-08-25 by mod - pre-finished Homasote-type fiberboard ceiling panels, T&G

Tim, I have certainly seen this product before, such as in this hurricane-leak-damaged home (above) and separately in a 1960s home in Two Harbors Minnesota.

The Minnesota building was originally constructed as a flat roof structure using insulating board roof panels that sported a finished-surface on the interior.

But I haven't found the exact product name for your photo and I am continuing to research it.

Examples of more contemporary Tongue and Groove Ceiling panels included products made by

• Armstrong Ceilings, sold as MDF Wall and Ceiling Panels
• Homasote EASYPLY® ROOF DECK PANELS [PDF] HOMASOTE COMPANY, 932 Lower Ferry Road, West Trenton, New Jersey 08628, Phone: (800) 257-9491 www.homasote.com, For Technical Support call Ext. 1332 or e-mail techhelp@homasote.com
• Homasote FIRESTALL ROOF DECK PANELS [PDF] Op. Cit. retrieved 2019/02/05 original source http://www.homasote.com/assets/files/installation/firestallroofdeck.pdf
• Insulated Roof Panels, various manufacturers
• See also FIBERBOARD ROOFING & FIBER-WOOD ROOFING - home
• SHEATHING, FIBERBOARD ASBESTOS CONTENT

On 2018-08-25 by Tim Tobin

The product in the attached image was removed from a house built in 1971. It's a 2-1/4" thick fiberboard tongue and groove roof decking. Homasote says it's not their product.

Can you identify or do you know of other manufacturers of fiberboard roof decking from the 1970's [shown above]?

My concern is the possible presence of asbestos. Thanks in advance for your reply.

On 2018-07-03 by (mod) - What "R" factor does 1 inch Celotex offer and does Celotex contain asbestos?

Gaylei

Since 15/32-inches thick (one board was 1/2") claims an R-value of about 1.5 a double thickness would double that to about R 3.0 per inch.

About your asbestos question please see SHEATHING, FIBERBOARD ASBESTOS CONTENT https://inspectapedia.com/structure/Fiberboard-Sheathing-Asbestos.php

On 2018-07-02 by Gaylei Nicholson

What "R" factor does 1 inch Celotex offer and does Celotex contain asbestos?

On 2017-10-22 by Adrian Harper

Hi, I'm trying to find the name for the fibre-type board I used as a base for a model railway. The name is something like "anaconda." It is relatively soft but rigid enough to support weight over a one-foot framework.

Any suggestions?

On 2017-08-05 by Jo

Hi, I just found some moisture rot on my window frame. I noticed it from the soft spongy corners at one side. Underneath the wood the sheathing looks like asphalt covered MDF.

I expected it to be OSB like on another part of the house. Its mostly OK except in the area where the wood was rotten. Its a bit soft there. I'm wondering if I can just dry it out and seal it over with resin on another product and replace the wood or might there be water damage further down.

Nothing apparent from the outside. It's quite dry here in Denver so the climate is a plus at least

On 2017-03-06 by (mod) - evaluate the condition of fiberboard sheathing

You need to examine the sheathing; if it is dry, not swollen, softened, disconnected from studs, nor mold contaminated it's probably fine.
I'm assumng you can see the wall condition from inside - as you'll have had to remove drywall and insulation.

It's essential that the veneer wall remains soundly connected to the building framing.

If the board is damaged, falling out, missing, then I'll have other suggestions for how to reconstruct the wall.

On 2017-03-06 02:09:49.220808 by Anonymous

My house was built in the 50's. In August my home took in almost 5 feet of water. I have this black board with Celotex written on it that is between the bricks and studs. My question is should this board be removed or is it safe to rebuild.

On 2016-05-04 by (mod) - solar panel mounts cause leaks?

I'm not sure that I agree that the solar panel mounts are properly installed if in fact they are the leak points.

It might be that the solar panel installer indeed installed using their standard procedures, so they defend what they did.

But if the panels are installed on top of a soft roof sheathing such as fiberboard, the installation needed to take that into effect. The solution might be a larger support pad under the solar panel mounts.

Properly anything supported on a roof sheathed just in fiberboard panels ought to be supported on and connected to structural framing such as rafters.

Certainly without adequate support wind rain snow and other forces will cause the brackets to move on the roof surface which increases the chance of leakage.

On 2016-05-04 by David

my cousin's roof has Celotex on top of tongue and grove roofing. The nails go through the Celotex and into the tongue and groove ceiling. The house was built in 1963 and re-roofed about five years ago.

My cousin had solar panels put on. Wind blows rain under the quick mounts,then up under the shingles ,and leaks into the house.the Quick mount is installed properly. The solar company has tried to fix the leaks four times. Now they said the shingles should have been nail to plywood. They want us to re-roof. Please help
they said the roof is not to code. Please help?

On 2016-01-23 by (mod) - if your roof is sheathed only with Celotex fiberboard I would worry

Guy if your roof is sheathed only with Celotex fiberboard I would worry that the shingles may blow off. I don't quite understand your situation.

On 2016-01-21 by Guy

When installing a new roof, can I nail shingles to the Celotex or should I cover with plywood/OSB?

On 2015-09-18 by (mod) - water resistance of Celotex fiberboard

Good question, Charlie and not one for which I could find data.

However I have read that because Celotex is a closed-cell product (really?) it has good water resistance and I found a builder commenting that he'd had "ok to use in flood zone" advice directly from Celotex technical support. That would have been before the bankruptcy.

My OPINION is that after flooding has subsided and the material has fully dried, if an inspection does not show swelling or mechanical damage, the material is probably fine. I understand that some products might show up deterioration later but this one is rather homogeneous and so less difficult to assess.

Unfortunately we'll have trouble asking Celotex technical support directly except for U.K. readers who can go to

https://www.celotex.co.uk/contact Technical enquiries: 01473 820850

http://www.celotextrust.com/ reports The Celotex Asbestos Settlement Trust was founded February 1, 1998 as a result of the bankruptcy of Celotex Corporation and Carey Canada Incorporated.

Originally, Celotex was a Delaware corporation reincorporated in 1964, which manufactured and distributed roofing and building products for residential and commercial use. Carey Canada, a wholly owned subsidiary of Celotex, was formerly engaged in the mining, milling and processing of asbestos fiber.

On October 12, 1990, Celotex Corporation and Carey Canada Incorporated filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code.
The Trust was created as a result of the bankruptcy.

On 2015-09-18 by charlie

Is any information available regarding long term performance of celotex sheathing that has been sbmerged during a flood?

On 2015-09-14 by (mod) -

Andre to permit space and citations I repeat your question and provide a detailed answer in the article titled:

FIBERBOARD SHEATHING FIRE RATINGS

Other readers. use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies

Question: putting stone veneer on fiber board sheeting?

(June 19, 2014) Amy VonArx said:
What are the spec's for putting stone veneer on fiber board sheeting? Do I have to cover with OSB or plywood sheeting first? My house was built in 1964 and has this on it. I want to stone veneer the front porch area.

Reply:

Amy, masonry veneer walls are typically supported by a structural ledger of steel, or by a foundation wall, and are also secured by mechanical connections to the building structural wall. There are also requirements for moisture barriers, weep or drain openings, and other derails.

Search InspectAPedia for

STONE VENEER WALLS

And

BRICK VENEER WALLS

To see articles discussing the topicc. Let us know if that material is unclear.

Question:

(July 29, 2014) Dan and linda said:
We have USG (black board) fiberboard as sheathing. I plan on re.sheathing over top of USG board with 1/2 plywood, than tyvek prior to siding house.

Any concerns with trapping moisture with this technique, or do I have to remove USG board?

Reply:

D&L

Presuming you are in a heating climate where the vapor barrier is in the building interior wall I don't see an issue with moisture from the double sheathing you intend. Be sure to use house wrap properly installed and flashed on the exterior walls.

Question:

(July 30, 2014) Dan and Linda said:
We are in NJ, is the vapor barrier considered inside or outside?

Reply:

in NJ the vapor barrier would go on the inside surface of the studs, i.e. the interior side of exterior walls, beneath the drywall.

This article series beginning at

inspectapedia.com/Energy/Vapor_Barrier_Condensation.php

discussed vapor barriers & their placement.

This article:

inspectapedia.com/BestPractices/Housewrap_Installation_Specifications.php

discusses placement of housewrap.

Question:

(Oct 11, 2014) judy said:
my handyman has used masonite board as a barrier to replace some discarded metal radiator covers. they are right next to the radiator and separated from the room by flimsy wood decorative covers. are there any health related risks (such as off gassing) from this arrangement?

Reply:

The material is basically wood fibers and a water resistant treatment such as waxes.

Question:

(Dec 18, 2014) Bob Shup said:
My sons crawl space has fiberboard glued to the concrete walls(for insulation value I assume), can we attach polyisocyanurate foam insulation board directly over the fiberboard? I'm trying to avoid the mess of removing the 60 year old fiberboard. Thanks for the help.

Reply:

(Dec 18, 2014) Bob Shup said:
My sons crawl space has fiberboard glued to the concrete walls(for insulation value I assume), can we attach polyisocyanurate foam insulation board directly over the fiberboard? I'm trying to avoid the mess of removing the 60 year old fiberboard. Thanks for the help.

Question: is Upsonite a Fire Risk?

(Feb 23, 2015) EH said:
Concerned about buying a home with Upsonite (upson board). Is there a fire risk? Would installing conventional drywall over the upson suffice?

Reply:

I'd consider fire-rated drywall not conventional drywall. See FIBERBOARD SHEATHING FIRE RATINGS

Question: asbestos in fiberboard?

(Mar 15, 2015) April said:
My home was built 1939. It is a story and a half. I have two closets on the upper floor that are finished with a fiberboard type of product. I am unsure exactly what the material is or what it is made of. Both the walls and trim are comprised of this material, and they are painted.

I am concerned that it could be an asbestos containing product because we have both exterior asbestos siding and some asbestos insulation around the ductwork in the basement. Would this material be fiberboard or something else?

Reply:

April:

Fiberboard as discussed here is not an asbestos material. Naturally I cannot possibly know what material is installed in your home from just an e-text.

But if you are not disturbing the material and it's in good condition, whatever it's made of it's unlikely that it's producing a measurable level of fibres in the air.

Question: fiberboard sheathing damage from an ice dam leak

(Mar 26, 2015) Marcus said:
We had an ice dam, have 1/2 fiberboard as sheathing, with 6.5 inch exposed wod shake siding with a 3/8 fiberboard in between coarses of shake, the board got soaked, how will this affect the performance of the board longterm, will the siding be more likely to fall off as the board may lose strength?

Reply:

Marcus

Typical fiberboard sheathing is treated with waxes and coatings to resist water absorption. I'm doubtful that strength loss is the first concern. More likely I'd be worried that water entered the wall cavity where it can trigger a problem mold reservoir or damage electrical wiring / devices.

I'd pick a most-suspect spot that got most-wet and make a small exploratory opening from the building interior to see what's going on in the wall cavity.

...

Continue reading at FIBERBOARD SHEATHING - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• FIBERBOARD SHEATHING - home
  • FIBERBOARD CEILING & WALL COVERINGS
  • FIBERBOARD PANEL REPAIR
  • FIBERBOARD PLASTER BASE SYSTEMS
  • FIBERBOARD ROOF SHEATHING
  • FIBERBOARD SHEATHED WALL BRACING
  • FIBERBOARD SHEATHING ASBESTOS CONTENT
  • FIBERBOARD SHEATHING INGREDIENTS
  • FIBERBOARD SHEATHING FIRE RATINGS
  • FIBERBOARD SHEATHING IDENTIFICATION
  • FIBERBOARD SHEATHING INSECT DAMAGE
  • FIBERBOARD SHEATHING MOLD CONTAMINATION
  • FIBERBOARD ROOFING & FIBER-WOOD ROOFING
  • FIBERBOARD PROTECT from WATER
  • FIBERBOARD SOUND INSULATION
  • SHEATHING, FIBERBOARD ASBESTOS CONTENT

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FIBERBOARD SHEATHING FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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