Interior or Exterior waterproofing better?


  #1  
Old 11-28-05, 04:56 PM
Ginger137
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Interior or Exterior waterproofing better?

Owned home for 2 years and 1st year leaks during heavy rains. Finally determined that a 4" pipe from the outside of basement South wall on side of attached garage does not come into sump pump crock just inside basement but stops short and is full of dirt. When water table rises water gets into crock and is pumped out and a hole was put in South wall right above the basement floor that lets water in which goes into crock during heavy rains. Same wall to the right seeps during heavy rains. the other 2 walls that join this wall (E & w walls) were waterproofed outside about 10 years ago and supposedly drain tile hooked into this sump crock. A lot of the basement has old knotty pine panelling so just uncovered the whole situation this summer. Have had at least 3 contractors look at this. The N wall has a crawlspace on it which doesn't leak yet. 1 or 2 times during extremely high amount of continuous rainfall the basement floor is damp enuf to cause some of the carpeting to get wet which concerns me but does not flood there. My choices now are get an inside system with tile around all 4 walls which would provide lifetime warranty on all walls and floor as long as all 4 walls are done. #2 waterproof outside of garage-side wall where water seeps in which involves breaking up garage floor. A few times have seen some leakage in E wall which was waterproofed 10 years ago but no longer under warranty. Would jetting out the tiles done 10 years ago on each wall as much as possible along with exterior waterproofing of S. wall eliminate this water problem with the E wall and basement floor? I could also get the same waterproofer to do the external waterproofing of S. wall that did the W & E walls 10 years ago but sounds fishy with the way the pipe isn't coming into the sump pump crock. And he acts like he doesn't know anything about it. would it be better to get the exterior on the garage side wall or an interior system on the 2 walls that are leaking and hope that either of these solutions will alleviate the floor wetness seen only 1 or 2 times so far? Basement is concrete block - house built in 1955. mostly clay soil (northern Ohio). I'm just not sure how much needs to be done and what is better for the house. Is exterior wping that much better than interior? Thanks for any ideas as I can't seem to decide on this.
 
  #2  
Old 11-28-05, 06:58 PM
Join Date: Mar 2005
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Interior or Exterior waterproofing better?

Before doing anything about drain tiles, make sure you have extensions on your downspouts (8' to 10' for clay soil). Make sure this water flows away from the house. With clay soil, your basement is sitting in the middle of a swimming pool, so you want to keep the water out of the excavated and backfilled area around the foundation.

Interior drain tiles are the best solution, especially with an attached garage or an adjacent crawl space.

If possible, I would suggest an interior continuous loop around the basement with drain tile entering the crock from both sides. This will allow you to jet out the pipe in the future if silt or clay happen to get in the drain tile. Interior drain tile does a better job of eliminating floor leakage than exterior tile do.

One advantage of a block basement is that you can go to optional extra some lengths (more $) by tapping into the bottom of the block wall with plastic tubing leading into the rock around the drain tile.

When the drain tile is installed, the bottom of the tile should have 2" of stone under it and the holes in the tile should be as low as the bottom of the footing. don't let the contractor tell you he can't go that deep. All he has to do is move the tile slightly (a few inches) away from the footing.

Dick
 
  #3  
Old 11-29-05, 02:27 AM
Ginger137
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Thank you very much. I already had new gutters installed and the downspouts do extend further than before but not as far as 8-10 ft. Regular extenders aren't very attractive sticking out from your house so I have flexible ones you see in HD - the brown or green ones everywhere. Guess I could add another section for now. The one WPer offers in-the-ground downspout extenders that a lawn mower can go over w/no problems. One downspout was eliminated which was near the leaking area but now during heavy downpours that section of the gutter has water running over the sides creating the waterfall effect near the foundation. So that section has to be kept especially clean of leaves most of the time so I may have that downspout put back in or something changed there.

Not sure what you mean by plastic tubing going into the rock....do you mean rock in the ground (under the floor) that is around the new tile? Also, if the tile s/b laid at the bottom of the footer wouldn't the drain trench have to be about a foot or so inside the perimeter of the basement walls?

do you think the interior would be better due to crawlspace and attached garage due to convenience of waterproofing? I would rather do what is best for the foundation. i guess I would like the exterior done as am very curious as to what the previous WP-er did, but then the moisture that has appeared on the floor concerns me. Am also concerned that would be a mold problem with the indoor system or would be more difficult to sell as am seriously thinking of putting this on the market next year.

Again thanks for your reply ! Very helpful to a new homeowner. do you think I can wait til Spring to have this done? Its been leaking basically probably since I moved in but didn't notice til Spring of 2004 almost 2 years. Probably leaking much longer time.
 
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Old 11-29-05, 06:39 AM
Join Date: Mar 2005
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Interior or Exterior waterproofing better?

The plastic tubing I refered to is an option to drain water (if the is any) our of the cores of the block. The water could be from leakage or from frost in very cold climates. It goes into the rock fill around the drain tile, then into the drain tile.

The drain tile is a foot or so inside the wall and thr rock fills right up to the wall, so the distance from the wall is not a factor. The elevation is important to collect the water that seeps under the footing.

The attached garage prevents good installation of exterior drain tile unless you go all around the garage AND under the slab ($$$). I am not aware how the crawl space is configured. In slit level homes, I have seen the drain tile laid inside below and along the low wall. I would not dig up the exterior just to see what did not work.

Drain tile system all work the same way - collect water and reduce the water table around the footings. Each has its advantages. Often, it is a question of which can be installed to do the best job. attached gargaes a broblem with one type and finished basement are a problem with the other type. I know of home builders that always put in both systems on new construction because the cost is not that much at that time.

Mold in drain tile is not a factor since there is no food (cellulose) for the mold. Most systems have a sealed lid for the sump - safety and radon reasons. Interior drain tile can be a part of a radon mitigation system.

Dick
 
 

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