PERLITE
CONCRETE
SCHUNDLER

ROOF REPAIR
AND REROOFING
CONSTRUCTION GUIDE
The Schundler Company
150 Whitman Avenue
Edison, New Jersey 08817
732-287-2244 www.schundler.com



SCHUNDLER PERLITE CONCRETE

FOR REROOFING AND ROOF RENOVATION


An old adage or saying is that "God never meant there to be flat roofs!" Unfortunately, economics demand the use of flat roofs over many commerical, industrial buildings. Eventually these roofs usually have problems caused by leaks in the waterproofing membrane, loss of slope due to structural problems or a collapse in the underlying insulation, or from a variety of other normal, predictable failures.

A common problem is caused when the original slope of a roof changes, causing water to either drain in the wrong direction, or to begin ponding. When this occurs, the slope of the roof can be corrected easily with the use of perlite lightwieght concrete.

Perlite concrete can be used as a thin (0-4 inches) fill to correct slope to drain problems, it can be poured over irregular substrates, and it often can be installed directly over B.U.R. and gravel roofs (eliminating costly tearoffs.) And because it is so light, the addition of a perlite concrte layer does not substantially add to the overall wieght of the roof. In fact, in many of these applications, perlite concrete simply is placed over the existing roof to correct slope problems, and then new insulation (sometimes a perlite concrete deck) is placed directly on top.


What is perlite concrete?

Perlite concrete aggregate combined with portland cement and water produces a lightweight insulating concrete used for lightweight roof decks, floor fills, lightweight structural decks, insulation for steam and coolant lines, bases of cryogenic storage tanks, oven insulation, interstitial spaces in reconditioned water and sewer lines, interstitial floors in hospitals, lightweight pre-cast forms and blocks, statuary, basic fills, and many other applications where a lightweight permanent concrete is desired. Although many uses could be described in greater detail, the most common and well-established uses have been for insulating flat roof decks and for repairing existing roofs.

The physical properties of perlite concrete vary according to mix designs. Perlite concrete can be made with a dry density of 20 lb/ft3(320 kg/m3) or with the addition of sand or other aggregates up to 90 lb/ft3 (1440 kg/m3). The lower the density, the higher the insulating value. For most uses to maintain a proper balance between insulation value and compressive strength, a 1:6 (one part portland cement by volume to 6 parts perlite by volume) mix is chosen with a density between 24-30 lb/cf3 (384 and 480 kg/m3). This provides a k factor range of 0.58 to 0.66 Btu-inch/h-ft2-F (0.085 to 0.095 W/m-k) and a compresssive strength of 125 to 200 psi (986 to 1378 Pa). For specific applications requiring higher strengths or other special properties, consult a local perlite manufacturer or The Perlite Institute.



PHYSICAL PROPERTIES AND MIX PROPORTIONS FOR PERLITE CONCRETE

TYPICAL PROPERTIES
TYPICAL MIX PROPORTIONS
CEMENT TO
AGGREGATE RATIO
(BY VOLUME)
DRY DENSITY
RANGE
LB/FT3
MINIMUM
COMPRESSIVE
STRENGTH
LB/IN2
WET DENSITY
RANGE
LB/FT3
CEMENT
FT3
PERLITE
FT3
WATER
GALLONS
AEA
1:4 36-42 300 48-56 6.75 27 61 (a)
1:6b 24-30 125 38-44 4.5 27 54 (a)
1:8 18-24 80 34-40 3.5 27 50 (a)

FOOTNOTES AND NOTES:

  • (a)Consult your perlite manufacturer for recommended types and proportioning of air entraining agent.
    Whatever type and proportion is used, try to obtain 10-15 percent air in the wet mix.
  • (b)The 1:6 mix ratio is the standard mix used on most roof deck applications.
  • Note: When used as a floor fill, sand and fibers can be addd to increase strength.
  • For information on transit mix/ready mix applications and procedures, see our page Transit Mix Perlite Concrete--Guidelines and Procedures.

Ask your perlite supplier for more information about these mix designs, or contact: The Perlite Institute



INSULATING CONCRETE ROOF DECKS

ROOFING INSULATION

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.

REROOFING BASE

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
RUD.L.RUD.L.RUD.L.RUD.L.
03.9.1875.874.1.1776.654.1.1806.853.1.2164.00
17.9.1066.208.2.1036.988.1.1047.187.2.1154.33
211.7.0756.2812.0.0747.0612.0.0747.2611.0.0804.41
315.6.0586.3615.9.0587.1415.8.0587.3414.9.0614.49
419.4.0486.4419.7.0477.2219.7.0477.4218.7.0494.57
523.3.0406.5223.6.0407.3023.5.0407.5022.6.0424.65
627.1.0356.6027.4.0357.3827.4.0357.5826.4.0364.73

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.
NOTES:
  • 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.

CODE APPROVALS AND GUIDE REFERENCES

  • International Conference of Building Officials (ICBO)
  • Building Conference of America (BOCA)
  • Southern Building Code Congress (SBCC)
  • South Florida Building Code
  • Ferderal Construction Guide Specification FCGS 03501
  • U.S. Army Corps of Engineers Guide Specificatoins: CEGS 03510

TECHNICAL SUPPORT

  • FM I-90 Wind Uplist
  • FM Serial Report No. OC2AO-AC
  • U.L. Wind Uplift Construction No. 143
  • U.L. Wind Uplift Construction No. 250
  • U.L. Fire Rated Designs

U.L. FIRE RATED SYSTEMS
P405 -- 3 HOURS
P406 -- 3 HOURS
P215 -- 2 HOURS
P241 -- 2 HOURS
P251 -- 2 HOURS
P407 -- 2 HOURS
P410 -- 2 HOURS
P708 -- 2 HOURS
P810 -- 2 HOURS
P812 -- 2 HOURS

P902 -- 2 HOURS
P905 -- 2 HOURS
P907 -- 2 HOURS
P908 -- 2 HOURS
P910 -- 2 HOURS
P913 -- 2 HOURS
P916 -- 2 HOURS
P920 -- 2 HOURS
P921 -- 2 HOURS
P922 -- 2 HOURS
P923 -- 2 HOURS
P231 -- 1-1/2 HOURS
P513 -- 1-1/2 HOURS
P919 -- 1-1/2 HOURS
P214 -- 1 HOUR
P216 -- 1 HOUR
P246 -- 1 HOUR
P509 -- 1 HOUR
P511 -- 1 HOUR
P678 -- 1 HOUR
P903 -- 1 HOUR



For more information, please call or contact:

The Schundler Company

150 Whitman Avenue
Edison, New Jersey 08817
732-287-2244 or www.schundler.com
email: info@schundler.com

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