Concrete block basement leaking

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  #1  
Old 02-19-06, 06:46 PM
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Unhappy Concrete block basement leaking

I bought a house that was built about 50 years ago. I noticed today that the basement concrete blocks near to the floor are leaking. There is a big deck adjacent to the exterior wall, so that is must be very difficult to dig the outside and fix the leaking. Any suggestions? Thanks a lot.
 
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  #2  
Old 02-21-06, 06:04 AM
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Welcome to the forums

As you probably already know basement leaks are best solved from the outside. When that isn't feasable products like drylok work well. First repair any cracks in the foundation, then apply a liberal coat of drylok. You want to fill all the pores in the block. This will solve most water problems.

On the outside you may be able to alleviate some of the problem with gutters and correctly positioned downspouts. The more you can keep water away from the underside of the deck or atleast direct it away from the deck the better off you will be.
 
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Old 02-21-06, 09:46 AM
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Welcome to the forums

As you probably already know basement leaks are best solved from the outside. When that isn't feasable products like drylok work well. First repair any cracks in the foundation, then apply a liberal coat of drylok. You want to fill all the pores in the block. This will solve most water problems.

On the outside you may be able to alleviate some of the problem with gutters and correctly positioned downspouts. The more you can keep water away from the underside of the deck or atleast direct it away from the deck the better off you will be.
Drylock is one of the absolute WORST things you can do to a CONCRETE BLOCK foundation that has water problems. (This does NOT apply to poured concrete foundations, only concrete block!).

Even if Drylock were a permanent solution (which it absolutely is not), when you seal concrete block walls, the water will build up and stay inside the concrete blocks and will weaken the blocks over time. The water will climb higher and higher inside your blocks, with no way to get out! Once the Drylock begins to fail, you may have many leaks, will certainly have a VERY humid basement, and will have a structurely weaker foundation!

As already mentioned, the best solution is to eliminate the source of the water problem from outside. If not possible, waterproof the basement from inside using a drain tile-typed system which includes weap-holes drilled into the concrete block to keep water from building up inside.
 
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Old 02-21-06, 05:34 PM
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Originally Posted by hammer
Even if Drylock were a permanent solution (which it absolutely is not), when you seal concrete block walls, the water will build up and stay inside the concrete blocks and will weaken the blocks over time. The water will climb higher and higher inside your blocks, with no way to get out! Once the Drylock begins to fail, you may have many leaks, will certainly have a VERY humid basement, and will have a structurely weaker foundation! .



I have heard this several times but believe it to be a myth not founded in fact. It is extremely doubtfull that the block would fill up with water. Unless the ground surronding the basement stays constantly waterlogged [also means you got BIG problems] the moisture will for the most part leave the way it came.
I have dryloked basements that have never needed further protection but in problem areas it is sometimes necesarry to recoat every so often.
Obviously there are better ways to stop water infiltration than with paint but it is an economical option.
 
  #5  
Old 02-22-06, 07:45 AM
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I can personally attest that it is a fact!!
I just had my basement waterproofed on Jan 30-31!
I received 10 different proposals and have heard every different angle and pitch there is
and considered doing the job myself.

For time constraints, I did hire it out, however.

I had water has high as the 6th course (block) high in parts of my basement! When the weep holes
were drilled to relieve the pressure, it was like turning the spicket of the hose on for 10-15 seconds on some parts...and the weep holes were 3/4" diameter!

Granted, however, that if the water problem is minor and the cause of the infiltration is lower on the foundation, the water would not get so high inside the blocks...but that is a very specific condition and would be difficult determine from inside.
 
  #6  
Old 02-22-06, 07:47 AM
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Originally Posted by marksr
I have heard this several times but believe it to be a myth not founded in fact. It is extremely doubtfull that the block would fill up with water. Unless the ground surronding the basement stays constantly waterlogged [also means you got BIG problems] the moisture will for the most part leave the way it came.
I have dryloked basements that have never needed further protection but in problem areas it is sometimes necesarry to recoat every so often.
Obviously there are better ways to stop water infiltration than with paint but it is an economical option.
It isn't a myth and it has been proven.

Interior sealing of a block wall sealed in this way will develop a high concentration of moisture inside the wall itself if there is a water problem outside. Interior insulation on top of this interior sealed wall could cause freezing problems within the concrete or between the inside the blocks. If such problems do develop they could probably be stopped by adding exterior insulation, thus raising the wall temperature above freezing.
 
  #7  
Old 02-22-06, 01:07 PM
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Concrete block basement leaking

In most cases, interior drain tile are as effective as exterior drain tile and some cases, they are a better solution. An interior system also reduces the moisture under the floor slab. Both interior and exterior drain tile solve the problem by removing the water and not trying prevent it from coming in with a few mils of paint.

The question of whether you can install an interior system depends on the degree of finishing you have done in the basement. You will need about 2 feet of width along each wall you want to protect. The ideal system is a closed loop leading to the sump instead of a single line leading to the sump. A loop allows you to flush out the line if silt gets into the drain tile. Obviously, you cannot flush an exterior system.

I had the proverbial "geyser" with about 4 feet of water in the wall and outside the wall. This was caused by a very hard clay that would trap all water in the excavated area and not even soften until it was saturated for a month or so. The excavation for my foundation was a swimming pool.

I installed an interior system over a two month period working some nights and on some week-end days. My 12 year old son and hid "buddies" helped with some of the grunt work like carrying out dirt and bringing in rock to surround the tile. I hired a contractor with a saw to come in and saw the slab sections for removal, leaving a 12" section every 6 feet to prevent the wall from sliding in.

I dug a hole for the sump and placed it in clean gravel or rock. Then I worked my way around the basement removing the muck (sopping wet silt and clay). During this, I allowed the water to drain back into the sump and be pumped out. After the trench was dug, I put in 4" of rock and then the perforated pipe. I covered the pipe with rock. Because of the 2' by 6' open sections, I used Quikrete to make small batches and finished the concrete section by section.

I did not put drains into the cores of the block since I had a long established faith in the Thoroseal that I was going to put on the walls and knew that my house was built in a swimming pool, had long extensions and did not have a great source of exterior water (underground spring).

I applied Thoroseal and then finishing coat (Thorocoat? or Thorheen? I think?) and that was in 1980 and it is still working to my knowledge.

It may not fit your situation, but it worked for me (with some sweat).

Dick
 
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Old 02-22-06, 03:11 PM
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My Problem Any Info??

We just bought a house in October. It was built in 1932 and they used "Cinder"(??) Block not concrete block. Hope I am right there from what I have learned so far. Well they had 1 inch styrofoam insulation sheets all the way around the basement walls. IDIOTS!!!!!!!!! Anyway that kept the moisture in the block and ate away about 100 or so of the blocks. There were cracks I could look throught to the outside and see daylight. Also found some holes down near the bottom by the floor where I could stick 2 fingers in and it was very wet in there and lots of sand which I found odd along w/ my uncle who has built 2 houses. So I took a wire type brush and putty knife and scrapped and brushed the whole basement. I then took and used quikcrete w/ the stone in it and patched all the big holes. I then used quikcrete caulking and sealed all the minor cracks. Also I used Mortor Mix and Vinyl Patching to patch the block where it was completely defaced (I guess thats the word? An inch of the inside block just peeled away and left it very rough). I am done w/ all that and now half the basement is dryloc'd. LOOKS GREAT AND HOPE IT WORKS. When May roles around my uncle is coming up w/ his dumptruck and skid steer and is going to fix my lawn. Like I read above you need to fix what the problem is outside first. But can't right now its a little cold in PA!! BUMMER Don't know the word for this device but he is bringing his leveler thing that sets on a tripod and another person holds a stick!! (no idea what its called) We are going to slope the dirt away from the house. I have a patio out back and the worst part of the basement wall is adjacent to that patio so I think it is leaning toward and even against the house and it has pushed several block inward. So we are going to tear some of the patio out and put a float in.

Anyone else have any ideas let me know. I didn't have a whole lot of water in the basement but when it did rain heavy there were puddles in the center next to the furnace. I do have a drain but it is next to the bad wall where the patio is and that was where the worst of the water problem was. There were 4 or 5 holes that I filled w/ concrete that water would just run in and down to the drain.

THANKS AHEAD FOR ANY INFO!!??
 
  #9  
Old 12-13-06, 09:52 PM
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i tought i had problems,did the drylock smell so bad that you had to leave the house?i'm about to dryloc my basement but scared the smell my drive me crazy and my wife is pregnant,is the smell safe?
 
  #10  
Old 12-14-06, 10:57 AM
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The oil based dryloc has an extremely strong smell that will force everyone out of the house for several days. You'll want the latex version if that is a concern.
 
  #11  
Old 12-22-06, 03:27 PM
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Red face Interested in doing this in our basement..

Concretemasonry,

Hi. This solution you've described above is the answer to what we've been looking for. We live in an old family home w/a concrete block foundation and are not interested in the exterior repair process. The basement in unfinished, so we would not be sorry to lose a couple feet all around it. It would be great if you could help explain this whole process to us. We would like to do this ourselves. Also, was this expensive, or just alot of elbow grease?
 

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  #12  
Old 12-22-06, 07:11 PM
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Internal waterproofing

Hi,

I have done many internal waterproofing jobs in the past 15 to 20 years.
The opinions I have heard here are all correct but are also indicating to me that the subject is having a bad reputation in your country. Bad reputation for internal waterproofing stems, per my experience, from low quality jobs and acuumulated failures on the part of the "teller".

If you apply internal waterproofing technology to the book, you shall have no failures. Out of 100 jobs I can say I have had only 1 failure.

Ye- this is a difficult job. Ye- when the walls are made of blocks / bricks the chance of the failure increase dramatically. But it can be done. the trouble with block-walls is that they are not as stable as concrete. They tend to move and crack, therefore cracking the waterproofing layer. This can certainly happen but even if it does the re-corection is relativaly easy.

Now, the ONLY way to do inside waterproofing is by Hidaulic Cement materials. NEVER use anything else. NEVER NEVER NEVER.

The first preparation step should be treated as waterproofing in itself. Meaning: the basement is already waterproofed after the preperation stage. The waterproof layer that comes afterwards is the final blow to the problem.

I can not describe all the procedure in details here (could do it on email or if you show pictures) , since it varies according to the details of the area. In general:

1. Correct broken areas with special restoration-cements (that do not shrink when they dry, as the usual cement).
2. Plaster the whole wall with a mixture of cememt and sand 1:1 , water and Latex Glue (SBS), 50:50. Layer should be 3-5 milimeter thick.
3. Brush an hidraulic cement waterproofing material (such as Sika Top 107), 5 KG per SQM, with amesh in between the layers.

Preperation also include the use of flexible sealing-materials on certain cracks, especialy on the joints between the blocks to concrete elements. Main area that always cause trouble is the connection between the wall and the floor (there is always a crack there). On that last point joint you should do a small "triangle" of cement and cover it later with the mesh described above.

Its getting too long here... You can see pictures in my site here, if you read that weird language: http://www.itumen.co.il/site/gallery_viewCat.asp?ID=21 and also here: http://www.itumen.co.il/site/viewCat.asp?ID=29

Dont worry, be happy.
 
  #13  
Old 12-22-06, 08:24 PM
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Concrete block basement leaking

ituman -

The poster was for information on how to make a basement dry.

In all of the projects I have seen in Israel, I have not seen any similar to an American basement with the type of moisture conditions we have.

The key to a dry basement is to remove the source of moisture from outside and under the basement "living space". Internal waterproofing systems are proven and offer many structural advantages since they reduce the pressure on the walls and floor slab.



Old HouseW/Issue - The first thing to do is make sure you have proper gutters and downspout extensions (8' minimum) and have the exterior grade sloped away from the house. This is the key to a dry basement.

The classic interior drain tile/ waterproofing system is quite simple. It consists of putting preforated drain tile inside the footings, at or below the level of the bottom of the foundation footings. This collects the water in a sump, which is emptied, as needed, by a sump pump.

A sump pit is located and placed by removing the concrete floor and excavating a hole for the sump to be placed in. The sump pump discharges to the exterior for drainage away or to a sewer (if permitted). Discharge is usually not permitted into a sanitary sewer, but it may be permitted into a combined sewer system. The discharge line should have a check valve to prevent backflow and short cycling of the pump.

A section (12" - 18"wide) of the slab parallel to the exterior wall is removed. the soil is also removed to a depth slightly below the footings and several inches of rock is placed in the bottom of the trench. Perforated drain tile in then laid and the pipe is covered with more rock to 3" below the top of the floor slab. A filter "sock" may be placed around the perforated pipe to prevent clogging of the system. After that, a concrete slab is poured to cover the excavation and rock fill. Usually, the concrete is poured over the lip of the sump to prevent any tendancy to "float" when it is empty during a period of high water table.

The project is quite simple, but does require hard work since a substantial amount of heavy wet soil, rock and concrete must be moved in and out of the basement.

After the completion of the drain tile or water removal system, it is best to seal the interior of the basement and improve the appearance. This would include forcing hydraulic cement nto the joint between the floor slab and the wall and coating the walls with somrthing like Thoroseal.

One of the benefits of an internal system is that it can collect water from under the floor slab and reduce the hydraulic pressure that can result in leaks.

This method does not cause a loss of space within the basement, but does require access to the floor area adjacent to the walls during construction.

Dick
 
  #14  
Old 12-22-06, 09:11 PM
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Dick, thanks for the exlanation

And good to know you too.

There are some places in Israel that this system is being used (without the under-floor-drains). Its has its downside when there is a electricity power break (common in winter) or when the pump stops working.

Also - in an area with permanent underground water (like near the shore in the north of Israel) this will not work well.

Cool to know you have reality on Israel too. And good lack.
 
  #15  
Old 12-23-06, 02:47 PM
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Talking

Concretemasonry- Thank you for explaining that. We do, in fact, need to replace the gutter system come spring. But, I still think we will end up waterproofing the interior. We're very excited now that we know there is something we can do about it. Appreciate everything. Enjoy your holiday.

OldHouseW/Issue
 
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