i'm hoping my fellow posters can help me with a basement water leakage problem. live in Northern NJ and recently bought a 1928 colonial. basement has a den extension built in the 40's and a further 4'x 6' extension built off the den in the 1980's. it's concrete block sitting directly on a concrete poured floor. i'm constantly getting water leaking in through the first row of concrete blocks and on heavier rain days through the places where the floor meets the concrete blocks. tried internally sealing with a polymer based spray and hydraulic cement, not working. i remember a stretch where it didn't rain for 2 1/2 weeks and water was still coming through! (though not much).
what do you recommend? thanks for your suggestions in advance.
been reading much of the older posts and i'm much more informed thanks to licensedwaterproofer and richard.
question. if it take the external waterproofing route, what materials do i need and in what succession do i apply them and what equivalent products are available at a home depot/lowes? one contractor told me to buy a rubber based membrane that can be brushed on. thanks.
Excavate down to the footing/floor slab. Be careful not to pile the excavated soil at the edge of the excavation. Clean off the outside of the foundation walls, removing any loose stuff. Apply a thick brush coating of bituminous dampproofing, or even two coats. Embed a sheet of 6-mil polyethylene film in the wet dampproofing, running down the wall and over the top of the footing/floor slab. Backfill with pea gravel to within 6 to 8 inches of finished grade.
Did I forget anything, LW?
Architect (NY) and Home Designer (PA)
Posts: 2545 | Location: Tobyhanna, PA | Registered: 24 October 2005
First, its best to define problem(s), make sure WHERE water/rain is FIRST-entering. Some get water coming out of blocks/onto floor inside from ONLY openings at/Above ground.
Some of these are openings around basement windows, or just under a bsmt window or just under a sill, open mortar joints from ground UP, openings where any service line enters and so on. Had a lady call that lives in N Jersey, she had openings/problems with her Bilco bsmt doors.
You can run a water test w/a hose at ground level directly on outside of where you see/get water inside. When running the hose, don`t let it wet anything above grade, and run water near full blast,not a trickle....you WANT to know.
Ok, so your soaking the soil on outside of leaky area(s) inside, IF you begin to get water in then there are problems below ground, there are problems on Outside of hollow-block wall. Will most likely be crack(s),loose parging and you`ll need to 'waterproof' this area,all the way down to footing.
Scrape `n brush outside of wall, you should SEE the problem(s), apply hydraulic cement over ANY crack/opening, apply thick asphalt over wall, top to bottom/ened to end of area, apply 6 mil visqueen, backfill with most/all gravel-peastone, sand if you have to.
Juts make sure of where water is first-entering. Because if Only openings are 'above ground' then doing any kind of waterproofing isn`t necessary. You`ll simply need tuckpointing and/or bsmt window replacement or 'maybe' part of your problem is water is first getting in through/around bildo door(s), know what i mean?
Believe it or not one can get water coming out of first row/course of blocks, along cove due to openings 'above ground'...yes. It`s possible for water to FIRST enter in hollow blo ck through openings around bsmt windows,open mortar joints etc etc and, homeowner sometimes ONLY see`s water come out of first blocks at/near bsmt floor.
The fact you/some-others have water come onto floor a few days or weeks AFTER the LAST rain 'usually' means quite a bit of water is INSIDE of blocks...water can get locked-up inside cores of blocks, build-up/accumulate and it`ll then keep coming onto the bsmt floor days/weeks later. I know this may seem a lil strange but its the truth. The water you see dribbling/seeping out a week/whatever later when it hasn`t rained is MOST likely this.
I`ve seen water locked up inside block wall from first row/course off floor up to my shoulders, about 5-5 1/2' up off floor. This water will have to be drained-out of course but this amount of water can get INTO `n fill cores of blocks from EITHER cracks/loose parging on outside of wall and/or opennings at ground level and UP. Yes, lots of water can enter the blocks from any openings outside.
Most won`t have water get locked-up inside cores but SOME do, throughout our 30 yrs it seems like 1 out of every 10-12 will have some amount of water locked up in blocks,leaky area of wall.
Now, a lesser group of HO`s will have a 2-part problem. They may have a crack on outside of hollow block AND opening(s) around bsmt window etc...OR, may have a crack/loose parging on outside of leaky inside area AND a blockage under floor in lateral line-sump pit tile. They`ll need 2 different repairs to fix 2 separate problems
Rikky, as Rich says, be very careful if YOU are going to dig, do NOT pile soil anywhere near excavated area, even if there is concrete/driveway, i would NOT do this, risky.
Its best to haul this crap away anyways and backfill w/gravel-peastone so common sense says WHY pick it up,WHY shovel it twice....when digging down, shovel dirt in wheelbarrows and wheel out to street or an area where front end loader/backhoe can pick it up.
Piling soil near open trench adds WEIGHT, and alot of weight, to/onto 'bank' and could cause/help cause a cave-in. Cave in`s can smash you like a pancake, not kidding. Not saying every ditch/hole will cave in, not saying some who do pile soil near trench have cave ins every time but, WHY take any chance...its NOT worth it.
And again, zero-in on the outside of where you leak inside. If you have one wall, one PART of wall that leaks then thats where the problem will be, outside, either below and/or above ground...90% or so of the time.
Example, this HO had 2 part problem, MOST of water that they saw entering onto bsmt floor at/near first row/course of blocks was entering through cracks on the outside,but on wind blown rains some water would enter through opening around bsmt window, see PIC`s
after clicking link, you 'may' have to click "BACK" on the right side to view
pic 1...vertical crack near corner, some cracks are WIDER than others. Even a hairline crack CAN allow quite a bit of water to enter, most will only see the water come onto bsmt floor near cold joint/cove BUT its through the CRACK where water/rain is 'first entering'. HO also had mold and efflorescence on inside of wall where cracks are on outside.
2) roots 'could-can' WIDEN a crack 3) opening(s) around bsmt windows can also allow alot of water to enter blocks 4,5) another vertical cracks further down the wall, about 12' away from crack in pic 1
9-10) a diagonal crack that runs off the vertical crack, this crack goes down and turns-the-corner onto back wall, MUST find `n waterproof all cracks/openings
Alco,Dewitt make a good asphalt, been using em for 30 yrs, NO problems. i can`t remember name of good asphalt product sold in East, i used it in Pennsylvania....think it was 'Henry' something or other
Quikrete makes hydrualic cement. Hyd cement,visqueen, asphalt-tar you should be able to find at builders supply. Gravel etc can be delivered.
Here are some Pic`s of OTHER OPENINGS that can be just below grade, open mortar joints can be found Above grade too
pic 4) under sill, lady got water up high on poured wall inside bsmt in part due to openings under this sill. If more thought/care would go into waterproofing/sealing all openings then les folks would have problems. Not trying to crap on all builders, they obviously know alot more on other things than i do but NOT on THIS subject.They don`t know and/or care about potential leaks,openings below grade, nor do city inspectors so please Mr inspector , please don`t tell us most/all problems have to do with outside drain tiles. Your tests,books,info is wrong here
thorough and very helpful responses thank you both. in terms of attempting to define the problem the metal bilco door extension area is in the back of the house and it's not very big 6'x4'x4'. there are no punch out's through the floors/walls and no windows or trees nearby just dirt. i've sealed the door perimeter with caulk so i know no water is entering via this area. the water seepage comes up through the first row of blocks on one side (the side that's parallel to the backyard) and through the whole perimeter where the blocks meet the floor. it appears to rise up from under the slab but as you said that might not be the case.
interestingly i have two downspouts that run into the ground on each side of this area, both about 4-5 feet away. i dug up one and rigght underneath the soil there's a black plastic extension connection that runs underground towards the backyard away from the house on a steady decline. i dug out about 6 feet out before stopping since i heard you want to push water at least 3-4 feet away from the foundation to relieve hydrostatic pressure. it's possible these drains could be clogged and water is spilling out near the foundation. it's also possible water is coming back even though it's draining away from the house (house on a steadily declining property with the highest point being the street steadily downward to the backyard). still even if water is building up it shouldn't be getting in. i mean it's only 4 feet down so the pressure shouldn't be that bad!
a few weeks back i actually dug a 1 foot hole down to the foundation on one corner where one cinder block was leaking water. i saw no cracks in that cinder block on the outside or surrounding ones. what i did find strange was the edges of the concrete floor slab weren't quite symmetrical. it looked more like someone just poured the slab without any boundaries to shape it therefore i couldn't see the place where the cinder blocks met the floor. i'm wondering even if i waterproof can i get to the place where the floor meets the blocks.
I don't understand why you can't see the place where the blocks meet the floor. Does the floor not extend out beyond the face of the blocks? When you dug your hole, did you see any dampproofing on the blocks (black tar kind of stuff)? Just because water appears to come from a certain place, it doesn't mean water is entering that place. It could be that water is entering throughout your wall and just collecting in the bottom course of block, so the natural places for it to appear would be at the bottom course, and at the joint between the wall and the floor.
Your underground downspout piping may or may not be a problem. The easy way to find out is to disconnect the downspout from the pipe and put a temporary six- or eight-foot extension on it above ground, and see what happens after the next heavy rain. Or better yet, find where the piping comes out of the ground (if it does) and watch during the next rain to see if water is flowing freely out of the end of the pipe.
Architect (NY) and Home Designer (PA)
Posts: 2545 | Location: Tobyhanna, PA | Registered: 24 October 2005
richard i can see the cinder blocks that are connecting with the floor it's just the area around it isn't smooth concrete looks more like a rocky terrain (maybe that's the problem!).
there was no treatment of the exterior masonry whatsoever.
your suggestion on extending the downspouts to see the effects are what i was thinking of trying first. the underground piping does not come out of the ground anywhere so i'd have to disconnect at the downspout and extend like you said. it might just be that alleviating this condition could correct the problem so much that exterior waterproofing might not be worth it. appreciate your responses once again i'll keep you posted on status as i would imagine it's good to see your knowledge at work
The downspouts are probably piped to a drywell, and who knows where? If your soils don't readily absorb water, or if the drywell is either too small or improperly constructed and possibly clogged with silt, the drywell may not be working. If it's too close to the bilco access structure, it could be the source of the water. I say that because you seem to be getting water in only one side of your access structure.
If you had lots of general groundwater, and your access structure is completely untreated, then I would have expected water to enter on all sides, not just one. So my guess is that either the drywell is too close, or it has stopped working, or the pipe is clogged, crimped or broken. The downspout extension could well tell the story. But please bear in mind that we are really only guessing.
Architect (NY) and Home Designer (PA)
Posts: 2545 | Location: Tobyhanna, PA | Registered: 24 October 2005
richard in regards to the drywell one could exist or not. if one does exist i can tell you it's probably decades old along with the gutters and downspouts. are there any techniques aside from digging (sonar?) to locate a drywell?
Well, don't laugh...there's always a dowser, although it's a dying art and they are few and far between these days. Just disconnect the downspout from the underground pipe...I'll bet a miracle occurs.
Architect (NY) and Home Designer (PA)
Posts: 2545 | Location: Tobyhanna, PA | Registered: 24 October 2005
so tonight i tried waterproofers suggestion to run a hose around the perimeter and see what happens. sure enough the water is starting to leak through in the same areas and i found a couple of other cracks that are leaking. clearly the area needs to be externally waterproofed so i'm going to get starting excavating right away. thanks again.
couple of last questions before i get my hands dirty.
in inches how much gravel do you recommend between the basement wall and the soil?
i have a waterborne concrete sealer (Radonseal). i was thinking of spraying the external walls first, then doing the asphalt then polyethylene film. i figured it can't hurt your thoughts?
missed one. damp proofing or waterproofing materials for the foundation? i went to home depot and they had only damp proofing stuff at 70-80% asphalt. to find waterproofing i'll have to poke around some more. thanks.
You'll probably have to dig about 18 inches back from the wall, so that's what you backfill with pea gravel.
Dampproofing material is fine, just make sure it's on heavy and thick. LW recently mentioned a brand that he likes, but I don't think it really matters a lot. Black goo is black goo.
While the dampproofing is wet, embed a sheet of 6-mil polyetylene in it (often called Visqueen, one brand name of the product).
Don't forget to patch any cracks with hydraulic cement before applying dampproofing.
No making mudpies.
Architect (NY) and Home Designer (PA)
Posts: 2545 | Location: Tobyhanna, PA | Registered: 24 October 2005
one can get water coming out of first row/course of blocks, along cove due to openings 'above ground'...yes. It`s possible for water to FIRST enter in hollow blo ck through openings around bsmt windows,open mortar joints etc etc and, homeowner sometimes ONLY see`s water come out of first blocks at/near bsmt floor.
, please don`t tell us most/all problems have to do with outside drain tiles. Your tests,books,info is wrong here
