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Raymond Brooks
Posted: Jun 26, 2008 04:24 PM
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Foam Under Slab
Mason,I have a customer interested in spray 2" CC on the ground before the concrete is poured. Code officer says it needs to pass ASTM C578, which is for EPS. Are there any studies/reports available to confirm the suitability of this application. Thanks in advance. |
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mason
Posted: Jun 27, 2008 06:49 AM
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There is a specification for SPF, ASTM C 1029. This provides a description of closed cell SPF designated by type. Type 1 is 15 psi to 24 psi minimum, Type II is 25 to 39 psi minimum, Type III is 40 to 59 psi minimum and Type IV is 60 minimum compressive strength. Just match the physical properties of compressive strength and water absorption with the EPS C 578 specification and that should do it. By the way FEMA has listed ccSPF as a severe flood zone acceptable insulation. Meaning that it can get wet and dry out without losing its physical properties. There has been significant testing of ccSPF below grade and it holds up very well. The National Research Council of Canada tested it along with other insulation to below grade insulation on foundations walls and they concluded that it does not require extra waterproofing so long as the water table is not higher than the foam. I have sprayed to the ground then covered it with concrete in cold storage projects in South Texas. We used a vapor retarder on the ground first. |
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Posted: Jun 29, 2008 01:45 AM
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i have sprayed many slabs on grades with good results,,, we usually spray 2" as this is the grade usually set to accomodate boardstock for an r-10 spec under hydronic heat tubeing.... i have 2 sub zero freezers with 5" 2.0lb which have been performing well for 7 years now... i have numerous freezers down in amish land that must be workin well cause i aint been beat with a buggy whip for some time now.. when we apply 2" or greater we do not use a vapor retarding membrane above or below the foam slab... the key to sucessful application is a properly prepared grade...3/4 road stone...compacted,,dry, (the stone is an important part of the drainage plane,,,foam or no foam,, round here i see some bozo's are useing sand,,or limes wasted,,,or stone-fines,,this is just bad building science.."saveing a buck,,,and it compacts real nice for a perty grade"..it just doesnt promote drainage,,which is why it is there in the first place) we have shot 15000 sq ft slabs that have poured to within 2 yards predicted cement use...so yes,,you can get it smooth and consistent... hope this helps 'dude |
