R Value Tji Roof With Dense Pack Cellulose

R value measures how well certain building insulation materials can resist heat.

R value tji roof with dense pack cellulose.

Read this article to learn how to install dense pack cellulose insulation correctly. Me thods and verification of density. Then install the 2nd layer of foam. Cellulose is a superb air blocker.

The r value per inch decreases slightly as density is increased from 3 0 to 4 0 lbs ft3. Bag of cellulose in framing cavities from 2 in. At the end of the day s work you should count up the number of bags blown and then divide that number by the total square footage of walls ceilings and floor space insulated the actual square footage of the. Me thods and verification of density thermal conductivity vs.

With the cavity dense packed with cellulose you end up with a r52 whole assembly. Reduction in r value from 3 4 at 2 5 lbs ft3 to 3 3 at 4 5 lbs ft3 but insignificant. You want longer clear spans go with 14 or 16 tji and get an even higher r value r60 and r68. Then place metal on top of that.

This gives me a total r 51 plus still leaves about a 1 5 gap between the bottom of the sheathing and the insulation to vent it. The higher the r value the greater the insulation performance. This is all we spec. Know exactly how much you need with our project calculators.

The chart shows the r value and expected coverage for a single 20 lb. Dense packed in wall cavities should only be install at 4psf and it has a r3 8 3 9 per inch. Like many insulation materials it provides an r value of approximately r 3 5 per inch of thickness. I do not know about the performance at other densities.

When determining how much insulation you need don t guesstimate calculate. Blown cellulose in the attic is r3 5 3 70 per inch. Dense pack cellulose does an excellent job of stopping air movement and its hygroscopic nature allows it to absorb and release moisture throughout the seasons. Cellulose is not unusual in this regard.

Dense pack cellulose insulation. Ashrae handbook of fundamentals 2001 p 23 4. Flat roof there are a gazillion of these roofs that are uninsulated and need to be addressed. But air leakage through cracks voids and gaps is important responsible for approximately one third of an average home s heat loss.

The guy in the middle is jim fitzerald the absolute best guy in the world and he could not make it. Much cheaper than 6 of foam never mind dealing with hitting studs with 9 screws. After that i simply net off the bottom of them and dense pack the rest with cellulose so 7 5 at r 3 7 would give me r27 30. Spray foam installs faster but cellulose costs less.

Flat roof being dense packed the roof is opened up and cellulose is being blown into the roof cavity dense packing it.