I have a contractor adding about 1,000 sq ft to my home. Yesterday, the insulation sub started his work. I noticed they were stapling the insulation batts to the inside of the studs (16" OC 2x4's), and insisted they face staple them instead--per common best practices and the Residential Energy Code of Alabama (and International). They guys on the job basically said, "sure, whatever, the customer is always right."

Today, the manager of the insulation company prepared and had me sign a waiver accepting responsibility for damage to the drywall from face stapling the batts. The reason given is that face stapling batts onto 2x4 studs basically puts two layers of kraft paoer vapor barrier on the face of the studs (one layer from each of the batts on either side of the sutd). These two kraft vapor barriers will supposedly trap moistere behind the drywall where it is nailed to the studs, and lead to damage of the drywall and nails, and to the tape and mud if a seam is on the stud.

I am in Northern Alabama--in case climate is a factor.

The insulation contractor said he has personally observed drywall damage by moisture caused by face stapling in several homes, although it often takes 10-15 years for it to happen. He said the local utility company (TVA) no longer recommends face stapling for this reason. The whole attitude was that guys behind desks do not understand how things are in the field, so they do not care about this issue.

So, what's the story? Am I doomed? What is the best way to do this?

Or, from another angle, is there something that can be done prevents this condensation between face stapled kraft paper, or is this contractor doing something else wrong that makes his face-stapling trap moisture?

From the Owens.Corning web site:

"Should I staple the facing to the front of the stud or to the inside?

Either is acceptable. Most drywall installers prefer to have the kraft paper stapled to the inside. Inset stapling allows them to glue the drywall and gives a smoother surface to attach to. The flanges are not part of the vapor retarder so faced stapling does not give you a better seal."

The tale you heard from the contractor did not have the ring of truth, so I went straight to the horse's mouth for an answer and I found it.

Since the flanges are not part of the vapor retarder, a double vapor retarder is not created by face-stapling, so theoretically, moisture cannot be trapped there. Even if it were part of the vapor retarder, I would think that it would be compressed so tightly that moisture would not likely accumulate there either.

Anyway, the reason given doesn't hold water, and neither will the installation.

Richard,

Thanks for your advice. The insulation is Knauf, not OC, so I checked their site. It says either is acceptable, and does not say the flanges are not vapor retarder. I looked at the flange today, and noticed the Knauf flanges do have the black tar layer on the flanges as well as the rest of the paper.

I cannot see his motivation to blatantly lie to me and go so far as have me sign a waiver. He apparently had been burned before, and blames it on the problem I described in my post.

It seems 1 of 3 things is true:

1. He did have the problem he described, and the cause was as he stated, and the best practices need to change.

2. He did have the problem, but is was caused by some other poor practice, not the face stapling alone.

3. He is BS's me because of a hidden agenda (perhaps to keep the General Contractor and/or drywall installers happy, since the cannot slide the drywall on the face-stapled stuff.)

Maybe 2 and 3 combine to have the drywall installers slide the drywall over the face-stapled kraft paper, it tears and bunches, then the drywall reacts poorly to this over the years as he described.


As it stands now, I have the worst of both. I let him finish the house with inside stapling, but not go back and redo the face stapled. I will know if I have drywall problems due to face stapling, but (like most insulation failures) I will probably not ever know if my house coulda' been better if it had ALL face stapling.

In retrospect, I think I should have gone with all face stapling, then gone back to the manufacturer if I had drywall problems. But would they care after 15 years? Heck, would I still own the house?
?