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.
R value tji roof with dense pack cellulose.
Then place metal on top of that.
Cellulose is not unusual in this regard.
This works well for any mono slope or gabled cathedral ceiling.
Flat roof there are a gazillion of these roofs that are uninsulated and need to be addressed.
The higher the r value the greater the insulation performance.
Dense pack cellulose insulation.
Ashrae handbook of fundamentals 2001 p 23 4.
You want longer clear spans go with 14 or 16 tji and get an even higher r value r60 and r68.
Flat roof being dense packed the roof is opened up and cellulose is being blown into the roof cavity dense packing it.
12 dense pack cellulose insulation.
But air leakage through cracks voids and gaps is important responsible for approximately one third of an average home s heat loss.
Read this article to learn how to install dense pack cellulose insulation correctly.
Spray foam installs faster but cellulose costs less.
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.
I do not know about the performance at other densities.
Much cheaper than 6 of foam never mind dealing with hitting studs with 9 screws.
Like many insulation materials it provides an r value of approximately r 3 5 per inch of thickness.
When determining how much insulation you need don t guesstimate calculate.
Me thods and verification of density.
With the cavity dense packed with cellulose you end up with a r52 whole assembly.
This is all we spec.
Bag of cellulose in framing cavities from 2 in.
Then install the 2nd layer of foam.
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.
Blown cellulose in the attic is r3 5 3 70 per inch.
The r value of wet spray and dense pack cellulose insulation depends slightly on its installed density and the exact type of cellulose used but commonly ranges between 3 6 and 3 8 per inch 1 as measured by the standard astm c518 test.
Dense packed in wall cavities should only be install at 4psf and it has a r3 8 3 9 per inch.
Know exactly how much you need with our project calculators.
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.
Reduction in r value from 3 4 at 2 5 lbs ft3 to 3 3 at 4 5 lbs ft3 but insignificant.
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.
R value measures how well certain building insulation materials can resist heat.
