Delaminating OSB Roof sheathing

art wickerham · 01-05-2008, 03:29 PM

In an 18 year old house I viewed today I saw pieces of the OSB sheathing on top of the attic insulation. NO ventilation problems were noted and the delaminating was confined to each sheet of OSB and did not cross from one sheet to another. What would you tell the client.

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**Scott Patterson** · 01-05-2008, 03:44 PM

About the only thing that I know of that would make the OSB look like that would be moisture. Either from on top or from below. I guess that it is also possible that that the OSB could have been a bad batch.

Anyway it is toast and will need to be replaced.

Jon Randolph · 01-05-2008, 04:18 PM

Originally Posted by art wickerham

NO ventilation problems were noted and the delaminating was confined to each sheet of OSB and did not cross from one sheet to another.

If you look at the picture that I attached (I took the liberty of brightening it up) you can see that what was originally installed to allow for ventillation is now blocked with insulation. Looks like blown in cellulose insulation as well as fiberglass batts. They blown in was probably added after the home was built and they clogged the air passage.

As far as it being isolated to some sheets, it may be mfgr. defects in those sheets or it could be that the ventilation was blocked only at those sheets.

The only way to provide proper ventilation in an attic is with continuous soffit vents and a continuous ridge vent. If there are areas where the vent is not continuous or blocked (as in this home), there will be no air movement and moisture will take it's toll on the decking.

Like Scott said, decking needs replaced but ventilation also needs improvement or it will happen again.

Jon Randolph · 01-05-2008, 04:19 PM

Forgot picture.

Kevin Luce · 01-05-2008, 06:10 PM

Problem occured during construction?

It mentioned it on this web page.

New Generation OSB Sub-flooring

I agree with everyone else above, it needs to be replaced.

Where you able to walk on the roof or was there snow on the roof?

**wayne soper** · 01-06-2008, 06:21 AM

Maybe the framer ate the OSB and left the potato chips. Just a thought.

art wickerham · 01-06-2008, 09:02 AM

Unfortunately the roof was snow covered. Also the sheets of OSB closest to the soffet vent did not delaminate. Not all of the OSB in the attic was delaminating, mostly only on the north side of the house and at the west end of the house. The owner just had a new roof installed less than a year ago. The buyer has asked for the delaminating OSB to be replaced by the roofer and the seller has agreed but they have not talked to the roofer yet. If the roofer refuses to replace the sheets what would you advise the buyer to do?

**Jerry Peck** · 01-06-2008, 09:24 AM

Originally Posted by art wickerham

The buyer has asked for the delaminating OSB to be replaced by the roofer and the seller has agreed ...

If the roofer refuses to replace the sheets what would you advise the buyer to do?

Have the seller pay for replacing the OSB?

What other choice is there?

(Besides walking away from the house or paying for it themselves, which it should not be their responsibility to do so - as long as they are willing to walk away from it ... )

Added: Depending on how old the house is, maybe calling in an APA representative to look at it and see if they say it is a manufacturing defect - send them a photo of it first. Go here: Contact Us | APA - The Engineered Wood Association and click on the email: help@apawood.org link

**Scott Patterson** · 01-06-2008, 10:06 AM

Originally Posted by art wickerham

Unfortunately the roof was snow covered. Also the sheets of OSB closest to the soffet vent did not delaminate. Not all of the OSB in the attic was delaminating, mostly only on the north side of the house and at the west end of the house. The owner just had a new roof installed less than a year ago. The buyer has asked for the delaminating OSB to be replaced by the roofer and the seller has agreed but they have not talked to the roofer yet. If the roofer refuses to replace the sheets what would you advise the buyer to do?

As a home inspector we do not give real estate advice. We report what we find and what needs to be done. End of story!

It is up to the buyer to decide what the next step should be, you should not even be having that type of conversation with the buyer. This is the point that a good real estate agent can earn their commission.

You need to tell your client that you can not give them real estate advice. You simply need to tell them that the damaged OSB needs to be replaced. You can not get involved in the How, Who or What delama.

Jon Randolph · 01-06-2008, 10:03 PM

Originally Posted by Jerry Peck

Depending on how old the house is, maybe calling in an APA representative to look at it and see if they say it is a manufacturing defect - send them a photo of it first.

You may be able to find a stamp (date and mfgrs. info.) somewhere on that sheet, but probably not due to the amount of delamination. In the future, looking for a date stamp on the affected sheet or other sheets in the same general area may help an APA rep. in determining if it is a mfgr. defect or other issue.