Tar paper vs. Plastic for foundation wall waterproofing

[anthonymmfalcone]

Dear Readers,

I've a block foundation wall with full basement. After heavy rains, water seeps in from one part of the wall and has bubbled the paint about 6" above the floor and seeped up along the edge between the wall & floor in the same area.

I want to excavate the exterior, install a sloped perf pipe drain along the footing, apply a dampproofing coating to the exterior wall, and apply either tar paper or plastic sheeting over the dampproofing.

Is tar paper better than plastic to waterproof the wall? If plastic, what thickness? The thickest plastic I can find at HomeDepot is 6mil, but I'm concerned that it might tear.

All suggestions appreciated!

-Anthony M. Falcone

[AAllc.architects]

Neither sheet material will work well by itself. The wall must be sealed. Here is one way to do it: Clean the exposed wall with a power washer and allow a day or two for it to dry. Repair chips, cracks, or holes to seal and give a relatively even surface. Using brush or roller, coat the surface. Make sure all pores are sealed. Use fiberd or non-fibered roof & foundation coating. Allow coating to cure for a day or two. Protect coating with asphalt felt paper or inulation sheeting. T

[marson]

I have seen plastic work. Use two layers--the outer layer gets pulled down as the backfill settles. I would think felt would be hard to keep on the wall during backfill. However, as long as you are going to the expense of digging it up, why not use a peel and stick membrane? WR Meadows Sealtite or Bituthene 4000 are a couple of many brands.

[hallerb]

Yeah membrame costs more but MUCH more effective!

DRAIN PIPE MUST MUST MUST be BELOW FOOTER LEVEL! Or your water will move from wall to floor level!:(

Been there done all this.

Honestly its way less work and expense to install a indoor french drain system.

No exterior digging. No digging it up again in a number of years when the drain line gets clogged with dirt, trust me sooner or later it will. no replacing plantings and lawn in effected area. system also removes water from below floor so high seasonal water table is no problem.

first make certain gutters are clean, downspout water goes at least 15 feet from foundation, and ground slopes AWAY from home.

I spent a summer and over 10 grand DIY trying to fix water problem from outdoors. hired contractors for some I was laborer:(

Installed outdoor perimeter drain, actually replaced old clogged one, a former owner had installed. backfilled to grade with rock, expensive since sidewalk being replaced, cant put new sidewalk on dirt it will crack, waterproffed outside walls, had many dump truck loads of excess dirt hauled away, new downspot a drain lines, all new resloped lawn.

high water table resulted in water coming up thru floor..... after all that money and expense:(

had interior french drain and sump pump installed for under 4 grand that fixed it all. should of done that from beginning:(

would of saved a summers hard work, although yard looked wonderful when it was complete.........

save yourself a lot of grief fix it from inside...

from one who has been there done that.........

[Greg]

When I did mine I rolled on the foundation tar coating and while still wet stuck 6 mil plasic up against it, that plastic is never going anywhere now.

[anthonymmfalcone]

One concern is the plastic may get brittle in a few years, no? Whereas tar paper may not. Now granted, tar paper would not be water "proof." It would just make it difficult to go through the wall and encourage the water to go down to the perforated perimeter drain.

[Noozer]

Check this out:

[marson]

Plastic would not get brittle below grade. But if you want to encourage the water to go down and into the drain tile, as another poster is suggesting, you use a dimple membrane in addition to dampproofing.

What this product accomplishes is reduces hydrostatic pressure against the foundation. Backfilling with sand accomplishes the same thing.

[hallerb]

interior french drain

[Kitep]

I have no idea which is better, but I have heard an important thing to do is backfill with gravel, not dirt. This'll stop water pressure from pushing against the wall and making its way through.