Replies

1. 
   Guest_ | Jul 14, 2000 03:02am | #1

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   The longer the better but there's a point when you want to backfill. Since it's best to permit the concrete to cure about a week before backfilling, you could dampproof just before the backfill. Say day 6. That's what I usually do.

   Want a drier basement?? Check out some of the waterproofing systems. Some are costly though. I usually install 6mil poly over the dampproofing tar while it's still wet. Even if you get some holes during the backfill, it's better than just the tar.

1. 
   Guest_ | Jul 14, 2000 03:47am | #2

   *Carole & Doug:Mike's right:the longer the better. Depends on the height, thickness of your walls, and condition of backfill(wet, dry, rocky, clean dirt). Most of our houses have 9' front walls and 7-12' subwalls so I insist on a minimum of 2 weeks before backfill with the waterproofing just before backfill.We primarily use asphalt coatings and occasionally apply fiberglass insulation board over the tar. I like Mike's suggestion of poly. Have sometimes used the Rub-R-Wall coating instead of tar.The premium systems in our area(North GA) are Trotter and B-Dri. Both offer unconditional guarantees of dry basement but are extremely pricey(last house $.65/sft for exterior and $7.50/lft for interior drain). Don't worry about these houses, though.The primary ingredient for dry basements is good foundation drainage. Final grading has got to move water away from the house. Sock pipe with gravel cover or perf pipe with fabric cover over gravel, installed at bottom of footer, and gutters with downspout drainage system are mandatory no matter which coating system you choose. If you keep the water away from the house, it can't get in the basement.This is one area you should buy the best you can afford. Appliances, cabinets, trim, carpet, etc. can all be upgraded easily but retrofitting a good waterproofing and drainage system can be an expensive proposition.Good luck and happy homebuilding.Bill