Hi,

Forgive my ignoreness, but before I get started with my theater build it seems I should work first on insuring my basement stays dry. Right now there doesn't appear to be a moisture problem, i have a sump pump, but there are signs of 3 cracks in one part of the basement that had water coming in at one time, and I see one crack that is actively leaking water.

With a sump pump, if I seal the crack with epoxy the theory is all that water should end up in the sump, right?

I also have a crack running around the entire perimeter of the basement (where the floor meets the wall) and another crack where the slab of the proposed theater meets the rest of the floor. There's no dampness or water in these cracks, but I feel like I should fill them to avoid any radon leakage (i had a radon test done about 2 months ago, my level is < 1).

So, before I put up any insulation, dri-core, or framing, what should I do to the concrete? I want to avoid mold, and that musty basement smell.

sounds like you need a professional.

Chisel out the cracks and seal with hydraulic cement

I used Mold resistent drywall as well. More expensive but worth the piece of mind, imho

Definately take care of the cracks on the walls. Check out my build to see similar issue I had to take care of before continuing my buid. The crack wher the floor meets the walls should be normal your wall are poured first then the floor. Sometimes a builder will do stress lines/cracks to relieve pressure on the concrete.

Check out this link for a similar product of what was used on my basement, very useful pics on how to do it. Pretty low cost.

http://www.appliedtechnologies.com/pages/content/crack_repair_material.html

I haven't had a problem since my basement was done.

I had a large floor to ceiling crack that I repaired with a similar injection product that oman321 linked to...

This is the one (Urethane kit with removable seal) I used: http://www.emecole.com/homeowner.php

There are specialty contractors for this. We have this problem in Pa. too. As time passes water finds its way through your foundation walls, so what will need to be done is the contractor will come in and cut through the concrete slab in your basement where it meets the foundation walls, and fill it with gravel over some PVC pipe to control the flow of the water. Then your room walls are built a foot in from the foundation wall. Owens corning has a special wall system just for this and it has excellent acoustical properties.

There are specialty contractors for this. We have this problem in Pa. too. As time passes water finds its way through your foundation walls, so what will need to be done is the contractor will come in and cut through the concrete slab in your basement where it meets the foundation walls, and fill it with gravel over some PVC pipe to control the flow of the water. Then your room walls are built a foot in from the foundation wall. Owens corning has a special wall system just for this and it has excellent acoustical properties.

I've seen references to that in several of the sites i searched for info. But that seems to be the exact same thing as having a full house sump drainage system already.

I had a large floor to ceiling crack that I repaired with a similar injection product that oman321 linked to...

This is the one (Urethane kit with removable seal) I used: http://www.emecole.com/homeowner.php

The previous homeowner got a quote to patch that crack with a urethane system, and it too was $500. Not sure why it's so darn pricey. That sounds like what I'll need to do for at least the one crack. But if the other cracks aren't actively leaking, should I worry about them as well? They may just be surface cracks on the interior walls.

Chisel out the cracks and seal with hydraulic cement

I used Mold resistent drywall as well. More expensive but worth the piece of mind, imho

Probably not for the actively leaking crack, but I was wondering if I can use it for the non-water producing cracks (i.e. just unsightly cracks that have no leakage).

Some sights i've seen recommend putting cement caulk into the cracks to seal them, that sounds like it might be the most economical (and easiest) approach where water seepage isn't an issue.

Now this is a thread I can really relate to...

IMO...

Fill one crack and another will start leaking... you need to solve the root of your problem... why is there water up against your foundation wall? My last house had the backyard sloped poorly... water would flow down it up against my basement walls. Other things to look for are that your downspouts are pushing water far enough away from your house. Take care of the water getting to your basement FIRST, then seal the crack, then finish the basement with peace of mind.

Nick

Hydraulic cement... Do a dampness test as well to see how wet the slab is. If there is a serious issue sealing it will cause other issues.

IMO...

Fill one crack and another will start leaking... you need to solve the root of your problem... why is there water up against your foundation wall? My last house had the backyard sloped poorly... water would flow down it up against my basement walls. Other things to look for are that your downspouts are pushing water far enough away from your house. Take care of the water getting to your basement FIRST, then seal the crack, then finish the basement with peace of mind.

Nick+1

Before I started my basement finish project I rented a trencher and routed all the drainspouts away from the house. My problem was that I have a daylight basement (the lot slopes gently toward the rear of the house) and all the water from the downspouts in the front and sides drained around the foundation. I didn't have any basement leaks, but the $400 spent on the trencher and pipes was cheap insurance before putting $45K into finishing the basement.

There are some good two part epoxy products available. Find a local concrete/contractor store, they'll have a kit for you to cover cracks up to a 1/4" thick. I think Silka was one of the brands. Basically mix the epoxy equally and then attach these port plugs over the cracks. Once the epoxy hardens, you inject a special premixed epoxy with a caulk gun to fill the crack, I've sealed three basements so far with this, an no problems. Don't fill teh crack between the slab and the wall though, at least not all the way around the basement. This can cause hydrostatic pressure underneath the slab and then you'll have even bigger water issues. Also do what Johnny suggested, find why water is seeping down there in the first place. Chances are you have some sort of landscaping near that wall outside, maybe some stones built up without proper drainage, this traps the water from rolling away from the house....

Nick and Scott hit the nail on the head. Take care of your water issues before they get to the house. All other solutions are secondary measures.

Thanks for the advice guys, sounds like i'll have to have a pro come out. The only "leak" is a 2" corner of one part of the basement, it's possible the downspout pipes are cracked or backing up. Odd that after three days of no rain, it was still damp.

My downspouts end in pvc piping in the ground. Where it goes, I have no idea. There is landscaping in front of the house where the leak is, is that part of the grade, or is grade considered where the clay undersoil is?

Don't fill teh crack between the slab and the wall though, at least not all the way around the basement. This can cause hydrostatic pressure underneath the slab and then you'll have even bigger water issues. ...

SO fill part of the crack, or none of it? If it's not bothering anybody, i'd just as soon leave it.

I guess I"ll need to contact a variety of water-proofing companies. Anybody know of a reputable one in columbus?

The first one I talked to when I bought the house said they'd need to dig out the entire foundation around the house, and seal it outside. They suggested that without even seeing the basement, or knowing what kind of issues I might be facing. That kind of turned me off. That is certainly a solution, but they quoted $15K to do it. No thanks.

Don't treat water problems, Prevent them.

See my response in the following link:

http://www.avsforum.com/avs-vb/showthread.php?t=1026463

Don't treat water problems, Prevent them.

See my response in the following link:

http://www.avsforum.com/avs-vb/showthread.php?t=1026463

I liked the gondolas in paris part the best.

The basement is, for the most part, bone dry. The sump pump was off for a year (the house was a mortgage foreclose before I bought it) and other than some water staining on the back wall, nothing is on the front.

I have severe drainage issues in the backyard, seems all 4 neighbors drain into my backyard, but it doesn't get up to the back of the house. It may be water table issue, in which case, that sucks.


Anyway, I'm calling a few guys tomorrow to come take a look. Re-grading the front is doable. I'm not sure how they'd figure out if a downspout drain is clogged or whatnot.