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waterproofing basements Post New Topic | Post Reply
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Thomas Kasper
Posted: Apr 18, 2007 08:56 PM
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waterproofing basements
I saw something new today. The concrete walls (outside)of a basement were sprayed with a "waterproofer". The material was black in color, very flexible, and rubbery. It looked about 30 ml thick. It wasn't polyurea. It was sprayed on. The house is about 2,500 sq ft. The homeowner said it cost $500. It also came with a warranty. Thats cheaper then the membrane you can buy at a home store!Does anyone have an idea what this stuff is called? Where to get it? I think it was sprayed through a proportioner. Thanks |
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Posted: Apr 18, 2007 09:38 PM
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Is it just an asphalt coating? That is very common up here, required by code prior to backfill. It is cheap and is "ok" at waterproofing. It is asphalt that is just heated and sprayed out of a pretty simple spray setup, nothing fancy. Tim Granite State Spray Foam Co. |
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Thomas Kasper
Posted: Apr 18, 2007 10:00 PM
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Yea, I think thats what it is. It was like tar. I wonder what kind of spray set up was used? Do you think it is the stuff that is used to seal blacktop driveways? |
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Posted: Apr 18, 2007 11:00 PM
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it is an asphalt type coating... it is a dampproofing,,,not a waterproofing...(basement walls can leak) recently read it can be ingested by common microbs found in the soil,,fascinating,,,but its gonna take one heck of a bunch of em to eat it all off of your foundation ( LOL ),,, (aint the internet great!!).. dampproofing///2"closed cellurethaneXXXXfoundation ah,,,insulation on the cold side of the wall... bueno,,bueno... |
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Timothy Sonney
Posted: Apr 19, 2007 12:52 AM
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they use the same stuff here. It has a very high perm rating. We call it "The Black Sh*t" We have sprayed the outside of basement walls with 2lb and then the guys with the B.S. came and coated the foam, just to meet the required perm rating for our area. The 2lb foam applied 2" thick has a higher R compaired to the rigid foam board and ours has no seams... |
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Posted: Apr 19, 2007 07:30 AM
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tim what perm rateing were they looking for.. 2" closed cell is about 0.8 perms... a good vapor retarder... the asphalt coating is a dampproofing membrane to assist in shedding of gross water,,it is not a waterproofing membrane,nor a vapor retarding layer... your application was in accordance to the spfa's recomendations for below grade on foundations,,, |
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Posted: Apr 19, 2007 07:33 AM
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ps..it also has a higher PSI rateing.. works great on grade for radiant heat too!! (shot 10K at 2" on monday for that application) remind the general to excavate the hole a bit larger to accomodate spray foam application to the foundation,,it can be a muddy,,,tight proposition,,,oh yeah,,beware of the wind and surrounding structures, vehicles, and other things prone to drift... |
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Richard Russell
Posted: Apr 19, 2007 08:41 AM
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BHI, when you spray a foundation outside for insulation purposes, do you foam above grade, up to the sill? If so, that will give a more uneven exterior surface than rigid foam board, so I would think that getting a decent appearance after covering with something for UV/weedwhacker protection would be difficult. If not insulating above grade, why not? I'm talking about a cold climate, without termite issues. Half the heat loss in a cold climate will be in that foot or so above grade. I saw an interesting web site with the diagram of heat loss from an uninsulated foundation as a function of depth, showing just how important that piece of exposed concrete above grade is wrt heat loss. As to the BS sprayed on, I wonder if what the OP was referring to was not the simple dampproofing stuff put on to satisfy code or one of the various products out there that go on much thicker, can bridge small cracks, and constitute (in theory anyway) true waterproofing. If the OP's case had a warranty with it, however meaningful, I don't think it would have been a simple dampproofing. |
