We came across this post from one of our fellow bloggers and thought you would be interested in it. Thanks to Jay Markanich, see Jay’s info at bottom of blog.
This much missing insulation can influence a whole room.
It doesn’t seem like a lot, but with insulation just a little that is missing goes a long way toward dramatically increasing energy bills.
This subject house was advertised to have had a new roof installed just a few years ago.
It was an older townhouse, and going into the attic space it was obvious that much of the sheathing had to be replaced along with the shingles.
That likely was the result of the roof shingles being very old at the time of replacement.
The previous roof may have leaked substantially, rotting the roof sheathing below.
It may have also had the older, bad Fire Retardant Treated plywood. I could see evidence of the older roof materials laying about.
But in the corner there was an area where the insulation was missing completely.
Perhaps it had been removed to get it out of the way when the roof was replaced, who knows.
It isn’t a large area, but large enough to influence the room on hot and cold days.
The temperature outdoors at the time of this inspection was about 55F, not very cold or warm.
But the sun was out, and look at how high the temperature was in the bedroom’s drywall on that cool day – 86F!
This is what the missing insulation looks like from inside the bedroom as described by a thermal camera. This would technically be referred to as a “thermal defect.” The room would also be graded by Energy Star and RESNET as “uninsulated” because it represents more than 5% of the ceiling space.
Studies have shown, and I have written before (click here), that only 5% of missing insulation can reduce the R-value, or resistance value, of insulation by 50%! That is significant!
RESNET and HERS rating systems define the grading of insulation in these terms: Grade I is the best, where “insulation is installed according to manufacturer’s instructions and completely fills cavities…”; Grade II is not bad, with some areas of missing or poorly-placed insulation and “moderate to frequent insulation gaps…”; Grade III as poorly insulated “with substantial gaps and voids.” And with a 5% void an area “is treated as uninsulated.” You can read the study here.
My recommendation: have your insulation checked! I do a thermal image sweep of the house on every home inspection, looking importantly for insulation defects. There are many things thermal cameras can find, but thermal defects are a big part of any thermal imaging investigation. Having a look around with a thermal camera can be very revealing.