Thread: Oversized insulation in floor structure

New construction home. Ventilated crawlspace in the Great NW. The space between the floor joists is 16" where there is not a large span and is 12" over the living room and kitchen(larger span). The insulation appears to be R-13 that is 24" wide and has been folded lengthwise and stuffed to fit. Very poorly installed with lots of small and larger areas that are missing insulation. I will be calling it out but am wondering if anyone else has seen both structure and insulation installed this way and what code references I can use(verbally) to support my findings as well as recommendations for repair. I know the buyers will be looking to me for advice so feel free to let me know what you would say/write.

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Originally Posted by Bill Anglin

New construction home. Ventilated crawlspace in the Great NW. The space between the floor joists is 16" where there is not a large span and is 12" over the living room and kitchen(larger span). The insulation appears to be R-13 that is 24" wide and has been folded lengthwise and stuffed to fit. Very poorly installed with lots of small and larger areas that are missing insulation. I will be calling it out but am wondering if anyone else has seen both structure and insulation installed this way and what code references I can use(verbally) to support my findings as well as recommendations for repair. I know the buyers will be looking to me for advice so feel free to let me know what you would say/write.

Crushing the insulation will actually reduce the R value. Unlikely to find anything in the code to cover this. This would be manufacturer's installation instructions and the code defers to the installation instructions. If you know who the manufacturer is, you can point them in that direction. If you don't then the contractor should have that information.

There is no code required to support your findings. The insulation is not properly installed, and has failed to stay in place, thus reducing its insulative effectiveness.

In my view thats all you have to convey, and that repairs/replacement are necessary.

The code does support the findings of crushing insulation and reduced R value.

The code even tells how much R value reduction based on percentage of compression.