Perlite concrete roof deck insulation is an ideal base for built-up and single ply roofing systems. It has superior wind and fire resistance over other roof insulation materials and with the addition of polystyrene insulation board sandwiched in the perlite concrete, high thermal resistance values are economically achieved.

Positive drainage is easily accomplished by varying the thickness of perlite concrete or by stair stepping different thicknesses of polystyrene insulation board and then covering it with a uniform layer of perlite concrete.

Perlite concrete insulation may be placed over vented or slotted galvanized steel decking, precast or pour-in-place concrete, or existing roofing materials providing a seamless, smooth, and hard surface ready for roofing. If exposed to water it will not deteriorate.

Perlite concrete insulation is ideally suited for reroofing applications. It provides permanent, cost effective, slope-to-drain designs with high R-values over flat and often-irregular substrates found in reroofing projects. Using a perlite concrete slurry coat, the polystyrene insulation board is positively attached to the substrate and covered with a uniform layer of perlite concrete insulation. If the existing substrate is sound and capable of the additional loading required, then the perlite concrete insulation can be applied to the existing roof thereby eliminating costly tearoffs.

R-VALUE1, U-FACTOR2 AND DEADLOAD TABLE3 BASED ON 1:6 MIX RATIO, 24-30 PCF PERLITE INSULATING CONCRETE
2 INCHES OF PERLITE CONCRETE OVER POLYSTYRENE THICKNESS IN INCHES	DEPTH OF CORRUGATIONS									STRUCTURAL CONCRETE 4 INCHES
	26 GAUGE 15/16 INCH			24 GAUGE 1-5/16 INCH			22 GAUGE 1-1/2 INCH
	R	U	D.L.	R	U	D.L.	R	U	D.L.	R	U	D.L.
0	3.9	.187	5.87	4.1	.177	6.65	4.1	.180	6.85	3.1	.216	4.00
1	7.9	.106	6.20	8.2	.103	6.98	8.1	.104	7.18	7.2	.115	4.33
2	11.7	.075	6.28	12.0	.074	7.06	12.0	.074	7.26	11.0	.080	4.41
3	15.6	.058	6.36	15.9	.058	7.14	15.8	.058	7.34	14.9	.061	4.49
4	19.4	.048	6.44	19.7	.047	7.22	19.7	.047	7.42	18.7	.049	4.57
5	23.3	.040	6.52	23.6	.040	7.30	23.5	.040	7.50	22.6	.042	4.65
6	27.1	.035	6.60	27.4	.035	7.38	27.4	.035	7.58	26.4	.036	4.73

FOOTNOTES:

1. R Values are expressed as ⁰F^.ft²h/Btu.
2. U Factors expressed as Btu/h^.ft²⁰F. Includes air films and roofing.
3. Dead Loads include weightof metal, polystyrene and perlite concrete roof insulation. Dead loads of structural concrete are not included.

• Insulation values are for summer conditions, heat flow down. To calculate winter conditions, heat flow up, substract 0.39 from the R-value, then add 1.5 for air films and roof, and divide into 1 for the U-value.
• U factors are based on series-parallel heat flow caluculations defined in the ASHRAE Handbook of Fundamentals and on test data by recognized, independent test laboratories. Thermal conductivities of roof deck components are based on 40⁰F mean temperature except perlite concrete which is based on 75⁰F.
• Perlite concrete properties are bsed on constant thickness insulation. For sloped insulattion, calculate average thickness.
• The U factors shown are calculations based on thermal conductivity data derived from laboratory testing of dry materials in accordance with ASTM Specification C 177. The values shown are intended only as guidelines. Actual insulation performance for all materials and systems is affected by design of building, environment, and installation, and will be lower than calculated values.

TESTING AND APPROVALS

Perlite roof deck insulation systems have been tested and approved for wind and fire ratings by Underwriters Laboratories, Factory Mutual, and of the code authorities. The system is rated as non-combustible by Factory Mutual. U.L. Design P-920 successfully achieved the fist 2-hour rating for any system of this kind under full-scale fire conditions. Perlite concrete roof decks with polystyrene insulation board meet the criteria for U.L. Class90 and FM I-90 wind resistance.

Back to Construction Products Main Page

Back to Home Page (Main Page of www.schundler.com)