as i said earlier i recently waterproofed a bilco door extension yet i'm getting seepage between the floor and first row of blocks on heavy rainfall days. would re-excavating and installing drain tile help at all? it would seem it would keep water from building against the foundation and make it less likely to seep in. i know it shouldn't be seeping in due to my waterproofing job but somehow it is and i've checked everything and i just can't see where it's coming from so a drain tile might be my best option. thoughts?

http://www.flickr.com/photos/32002376@N00/

Was there any water coming into your excavations? My guess is as LW has said, that water is getting into your block walls somehow, and seeping out the bottom. Is the water appearing near the main foundation, or is it at the other end, or in the middle? Maybe water is getting into the main foundation and running through the walls of the Bilco section. Did you extend the waterproofing onto the main foundation...at least a foot, and preferably two feet?

if you look at the pictures the 3rd one (img_1729) is facing the bilco door that leads out to the back of the house. the main foundation is connected on the left and right sides on perpendicular angles like so:

bilco door
| |
left | | right
wall | | wall
| |
----------| |----------
main
foundation


the water first starts creeping in in isolated pockets along the left wall which is waterproofed. then it eventually spreads and the whole left wall is wet like you see in the picture. the right wall which isn't waterproofed starts in much the same way but lags the left wall a bit.

i did extend the waterproofing to the main part of the foundation on the left wall about 6 inches out. is it really out of the realm of possibility that water is coming up from underneath the floor and making its way through these areas? my house is on a downslope and this bilco door area is the farthest down the hill so to speak. the water is running downhill and could be pooling here enough to bleed through. thanks again.

Was there any water in your excavations?

oops i guess my little drawing didn't come out right no richard there was no water in my excavations dry as a bone. on more info tidbit. on the outer wall where the bilco door sits it's dry as a bone now even after these 2 nasty rainstorms we've recently had (one going on right now). this is the place where 95% of the water was flowing in from and the waterproofing job absolutely did the trick. this is why i'm stumped as to where this seepage is coming from. there is no seepage on the outer wall.

when you say "waterproofing", what did you do? - A surface coating?

A classic, proven method of sealing the floor/wall joint is to open up the joint and force in hydraulic cement. As the cement cures (it does quickly), it expands to fill the joint. This is commonly done on dams and commercial structures and similar applications. Usually, the joint between the slab an wall widens as the concrete slab cures and pulls away. You could try a soft joint, but the concrete really should be bone dry(almost impossible if it is in contact with the soil) to get any adhesion.

The water is probably slightly coming up from below and seeking the easiest path. Often, the excavation and backfilling around a basement or Bilco door can allow surface water down to where it will accumulate if the natural subsoil is relatively impermiable.

When you are done, coat the inside of the wall with something like Thoroseal and NOT DryLok.

Granted, it is a "band-aid" solution since the cause of the leakage (the water) is still present, but it proven and very durable. You can also do it when the concrete has moisture in it.

Obviously, drain tile would work since it removes the water and eliminates any hydrostatic pressure that could force leakage. It is a mess and probably not worth doing now unless other methods do not work.

****

thanks for your comments.

quote:

when you say "waterproofing", what did you do? - A surface coating?

i did as waterproofer and richard recommended. wire brush external wall, thickly cover with a rubberized roofing cement, visqueen over it and backfilled with round stone.

quote:

Often, the excavation and backfilling around a basement or Bilco door can allow surface water down to where it will accumulate if the natural subsoil is relatively impermiable.

interesting point. now that the soil has all but been removed and it's nothing but backfilled stone the water could be sitting and accumulating near the footings where before the soil at least sopped up some water so it's making its way in. this is why i asked if a drain tile would work to move water away from the area so its not sitting there trying to find a way in (which it has).

i have one other thing to try first. i have 2 downspouts that enter the ground about 4 feet away from the bilco door extension on each side that could be contributing to increased water in the area. there are underground plastic extensions connected to the downspouts that run away from the area but they could be clogged for all i know they're old.

question. is there any way to seal the floor wall joint from the inside? i'd hate to have to dig up the outside again it was quite a bit of work. thanks.

The method of sealing the wall/floor joint I suggested would be done from the inside. It can be very effective. It hate to call it a "band aid", but because it does not eliminate the cause, it is technically a "band-aid" just like coatings applied after construction. It is cheap accessible and and the most difficult part is creating an open joint (dove tail shape preferably) and following the the classic hydraulic cement instructions.

Regarding your downspout extensions, I have two that are about 20' long and use the pop-up ground level discharges. They work well. You can always check out the extensions by disconnecting, inserting a hose and look for the discharge. Sometimes they get plugges with leaves, seeds and acorns.

Good luck!

thanks again. even if i had access to the outside you can't see the floor/wall joint its behind a layer of concrete that was lathered over the cement block wall and footers during construction. i remain completely baffled as to where this water is coming from hence my stab that it might be coming from underneath i just can't see where else it could be entering.

drain tile does NOT eliminate hydrostatic pressure....tile on inside or outside.

drain tile may divert 'some' water out towards street,backyard or if its inside, will divert 'some' water to sump,floor drain etc.

but drain tile will not eliminate the accumulation of all water under a basement floor or outside, along a basement wall. it will not get rid of expanding-contracting soil pressure, roots etc, you want to believe this nonsense thats your choice.

waterproofer you've helped educate me enough to know drain tile is not going to solve the issue just potentially diminish it. my problem now is i can't identify where this water is coming from. i was thinking if it's not coming from above grade maybe i missed a spot in the waterproofing and it's finding a way in and bleeding along the floor/wall joint.

the first time my waterproofing job was put to the test was last wed morning when we got 3.12 inches of rain in 3 hours. the outcome was the pictures i supplied in the link above. when i got home from work i put a fan on it for about 20 minutes and it dried up and never seeped back in. seems whatever pressure was there went away pretty quickly. ugh this one is going to bug me until i can find out what the heck is going on.

you might, you could have a partial blockage under the bsmt floor, i`m saying its possible is all. Some folks have a 2-3 PART problem, and sometimes, unfortuantely, it can be a pain in da az to find them all, takes time `n patience.

Let me ask you, this last rain you folks got there.....would you have normally got water in on floor in those areas BEFORE you did your waterproofing?????

quote:

his last rain you folks got there.....would you have normally got water in on floor in those areas BEFORE you did your waterproofing?????

during the 7 inch deluge that hit us in april we did get water in the same spot however at other times of heavier rains we would see a little dampness but nothing to the extent as is happening now.

latest update. we had 3.12 inches of rain last wed morning. that's when i took the pictures in the above link. so far today we've gotten another 2 inches so far. the seepage is worse than last wed morning. it's not standing water but it's wet.

waterproofer, what do you mean by a partial blocks under basement floor? how do you deal with such a thing?

for 'some' HO`s, they have could have a blockage under the bsmt floor, could be a blockage in the lateral line that goes out to street and/or, a blockage that is in other direction under the floor, towards the back.

Either can cause water to accumualte under a floor and on longer rains it can rise-UP through any openings/gaps in the bsmt floor, in only one area or, many areas.

'IF' this is part or all of their problem they`ll need to try and snake through the storm cleanout, both ways/directions when possible.Not all plumbers 'get' this!

Thats one way, another is when a HO has a sump pump, the drain tile that empties into the pit can get clogged and can cause water to accumulate and rise up, just like lateral line problem.Good honest plumber will have to snake through the drain tile to free blockage IF this is the problem. Most-not all plumbers around here charge 'around' $125-150...depends on how long it takes em etc, may cost a lil less or a lil more.

thanks. i have an interesting layout in my basement. let me start by saying it was built in 1928. they put in a poor man's french drain which is a 2 inch trench in the concrete that runs around the inside perimeter of the house and slopes down to a 6 inch circular hole in the floor in the center front part of the basement. when i look down this hole during bad rains i can see water running away from the house, kind of like a stream. my house is on a downward slope and the water runs opposite direction 'up the hill' so to speak where the street is. i always wondered what style of drain this is is and how far in either direction it runs. sounds like a good idea would be to snake this hole in both directions until i hit an obstruction?

If your excavations were dry as a bone, it's hard to see how there could be enough water pressure to force water through that floor/wall joint. The pressure would dissipate in your gravel backfill first. My guess is that water is getting into the block by some other route, and what you are seeing is the water seeping out of the block and on to the floor. That's my guess. I have solved a few water problems, also, by suggesting that clients disconnect their downspots from the underground piping, at least temporarily, and extend them six to eight feet away from the house. Sometimes, the water intrusion stops, and that identifies the downspouts as the source of the water.

thanks richard. i'm going to try the downspout disconnect. i'm also going to take some pics and upload them to show you what today looks like after 2 more inches of rain only 2 days after i got 3.12 inches of rain.

Rikky -

To repeat and as Richard suggested, the downspouts should certainly be looked at, if only for the sake of the general water/drainage problem. They are too close to the problem to be ignored.

Since your home was built in the 1920's that brings up some possiblities. The trench "feeble" basement drainage system was used in many homes in the NY, NJ, PA, etc. area in the past has generally been discontunued and is not permitted in most areas. It does not really dewatering like a proper "french" drain. Often, the drainage goes into the city sanitary sewer.

You should find out where your downspouts are drained to. Just disconnecting them will not definitely tell you where they go. If they dump into a dry well near the house, they could be adding water around and under your house. If they collapsed through the years, they could also be dumping water too close. Disconnecting them and a combination of using a snake and running water may give you a clue about the route, condition and discharge point. If the discharge is not free, it is very easy for the pipe to be plugged and back up water toward the house. Leaves, bugs, acorns and other debris can also easily plug them. Richard's suggestion to look at where the water ends up is very good.

One thing about observing leaks and water showing up. - Concrete will absorb moisture, but if there is air circulation, it could be described as "saturated, surface dry" which means that it looks dry, but cannot hold any more water. Any small amount of additional water will show up easily. Your slab and footings may be saturated and sitting in saturated soil, but appear to be completely dry. A little extra water (and little or no pressure)is all it takes to show up at an open (unbonded)joint between two pieces of concrete. This could be your situation and a little water from a good gutter sytem could very easily create the situation shown on your photos. - Last I checked, no one has invented a big "baggie" that covers the bottom of a home.