As municipalities adopt new codes, code officials are beginning to verify compliance. And in some cases, it has not gone well. One recent example is an apartment building in the Dallas-Fort Worth area. Blower door tests were done on the first completed units. When the official reviewed the results, it showed a one-bedroom unit (less than 800 sf.) having 1290 CFM of leakage, so he refused to approve the certificate of occupancy.
To put it in layman’s terms, 400 CFM of leakage is equal to one ton of air conditioning. That’s right , this one-bedroom apartment had over three tons of leakage. So, in a climate zone where building codes are wanting three air changes per hour, this apartment was coming in around ten.
Since the insulator was responsible for the air sealing package demands were for the insulation contractor to make it pass in order to meet code. The problem was, it wasn’t the insulator’s fault. He had already tried to get the builder to add a top plate gasket to the project but got turned down. Now that the drywall was in, the only solution to stop air escaping through that area would be from the top. This was obviously much more challenging and far more expensive than the top plate gasket would have been. At first, the builder wanted the insulator to do this at no charge. That wasn’t happening, so after a couple of days, a potential solution was proposed for a trial, the insulator held their ground, and the builder finally agreed to foot the bill.
The proposed solution was simple: Vacuum out all of the fiberglass and air seal the head of every wall. Foam kits were sent up to the attic and every top plate was encapsulated from above. This could have been done with gun foam, but this was one unit, of one building, in a multi-building complex. The solution needed to be fast.
Once everything was sealed, new blower door tests were done on the unit and the results were better than expected. The same unit after sealing the top plates came in at 473 CFM of leakage, a drop of 817 CFM. The code official approved, and the insulator was paid to fix the entire complex.
All of this could have been avoided with the installation of a top plate gasket Be sure to check out IDI’s 2018 blog and video with tips on installing and selling top plate gaskets.
Lean on the Experts at IDI for More Insulation Advice
Hopefully, this blog and the one from 2018 help you increase sales with your builders and eliminate some of the headaches or challenges in meeting air tightness goals. For more information on top plate gaskets or any of the products we sell, reach out to your local branch or contact the corporate office where our goal is to help you profit and grow.