 |
|
|
| |
EICRS |
ISO |
| Board Aged R Value |
3.85 |
5.56 (Note 1) |
| For R-19 |
2" Elastizell + 4" E.P.S. = 6" |
3/4" Perlite + 3" ISO + 1/2" GypBd = 4-1/4" |
| For R-30 |
2" Elastizell + 6-1/2" E.P.S. = 8-1/2" |
3/4" Perlite + 5" ISO + 1/2" GypBd = 6-1/4" |
|
| Weight |
8 psf |
2-1/2 - 3 psf |
|
| Conclusion EICRS |
Requires only an additional 2-3" thickness
and 5-6 psf loading |
|
| Sloping Capacity |
Excellent - flexible
Custom slope as needed |
Fixed - Rigid
uncompromising |
|
| Strength |
160 psi min. |
25 psi |
|
| Durability |
Excellent - not affected by normal foot traffic |
Poor - foot traffic strains membrane |
|
| Heat Sink |
Lower R-value of top 2" diffuses thermal shock |
High surface R value produces thermal shock |
|
| Fire Rating |
Will not burn - meets ULP921 for a one or two-hour fire rating |
Rated non-combustible but requires below deck fire protection and barrier board |
|
| Shrinkage |
Only 0.3% |
Allowable shrinkage per ASTM C1289 is 4% linear change - needs cover board per N.R.C.A. |
|
| Environment Values |
No ozone damaging gases |
HCFC blowing agent destroys OZONE - Must be eliminated in 2003 |
|
| Installation Rate |
Up to 10,000 sq. ft. per day |
Considerably less |
|
| Installation Problems |
| On concrete |
None - install roofing after 3 - 4 days |
Wait up to 28 days |
| On metal deck |
as above - i.e. entire fire rated assembly is installed simultaneously |
Project delay as below deck fire proofing should be installed after roofing. Will interfere with mechanical installation. |
Note 1:
The aged R-Value of isocyanurate board is 5.56, far less than the advertised 7.2 or even 8 touted by salesman. Note the small print disclaimer for E'NRG'Y2 by John Manville. From 7.2 to 5.56 is a 22% drop in insulation value - i.e., theoretical R-19 is a R-14.8! Even less when you consider the gaps due to the shrinkage of the board and the direct heat transmission of the metal fasteners. |
