finishing my basement

[tony.belden]

I have started finishing my basement (full, not a walkout) by painting all four walls with 2 coats of DryLok.

One issue is that there are 2 cracks on the basement floor, running criss-cross from middle to middle all the way across each way. It bisects my rectangular basement 2 times and into four equal parts. Those cracks are straight and have not changed an iota in the six-plus years of the house's life. Should I seal them with some kind of concrete repair product or just leave the cracks as they are and build over them? Should the cracks even be there? The builder said to me that they were caused by shrinkage/curing and that they are okay. I wasn't entirely convinced.

The house is six years old and I have been running a dehumidifier down there pretty much nonstop in the summers and autumns these last 2 years. With the Drylok applied, the amount of time it takes for the dehumidifier's tank to fill has increased dramatically...from twice a day to twice a week.

The moldy/mildewy smell is gone now - it was pretty bad until I cleaned the basement, started running the humidifier, threw away or sold a bunch of the stuff down there, and moved a bunch more to my shed that I built last year.

Now that I've DryLoked my basement I'm trying to figure out how to start to build out the walls.

To me it makes the most sense to put in a gap so that, should moisture seep through the concrete (in the form of vapor), the moisture has somewhere to go. Then I'd put fiberglass between the studs, paper out, and find some way to hold it back so that it didn't touch the painted concrete.

Is there a product out there that will hold the fiber insulation within the studs so that it does not pop out and touch the concrete?

A lot here I know, but I've pretty much decided how I'm going to do this...I just hope that someone can chime in here and let me know if I have my head up my butt. Everything I've read indicates that there is no "right" way to finish a basement...once you decide to finish it, there's nothing to stop water from coming in if it wants to. What I'm trying to do is make reduce the risk of water vapor seapage condensing onto any surfaces.

Thanks, Tony

[The Reverend Natural Light]

I'm following the advice in a "how to" book while refinishing my basement. Here's what I'm doing:

1. Fix a grading problem outside to stop water seepage.
2. Drylock applied to block walls.
3. 2x4 framed walls built as close to block walls as possible while still being straight and plumb.
4. R12 fiberglass batts between studs, no paper.
5. Plastic vapor barrier stapled to studs on the interior side.
6. Drywall.

Step 4 is next, after the electrical inspection. Once you've fixed the water/vapor coming in from outside (sounds like you have) the next source of dampness is the inside humidity condensing on the cold concrete. Thus, the insulation and the plastic on the 'warm side' of the wall is the key.

At least I hope.

I can tell you what *not* to do, or what seemed to be acceptable in

1969: Knock holes in the block with a sledgehammer to mount electical boxes. Nail furring strips to bare block. Apply dark wood paneling to the furring strips. Lay down asbestos tile and call it a finished basement.

That was one spectacular mess to clean out.

[I R Baboon]

cant help you about the cracks in the floor as im a carpenter not a mason, but, before you start framing your walls along the block walls, get a roll of plastic and staple it to the top of the wall and let it hang all the way to the bottom. that will keep the insulation away from direct contract to the wall. id also keep a gap of at least 1/2" between walls

[yustr]

Depending on where you're living the cracks might be a path for Radon to enter - I'd seal them.

As for the walls, I used ridgid foam insulation and 2x3's nailed directly into the concrete wall in place of studs and fiberglass. Easy, solid and forms the vapor barrier.

[jaykchan]

I am not an expert in this area. But I guess if the crack doesn't increase and your doors upstair don't stick. I will not worry about this.

This is my experience too with the use of DryLock. But mold and mildew will still find their way to the bottom of the wall near the floor. Because you cannot paint over the floor (for various reasons), moisture will still going up from the floor (such as when rain water is not being channeled away from the house foundation). Therefore, this is still very important to channel rain water away from the house foundation.

The mildew problem in my basement goes away after I have done these:

- Extended the downsprout away from the house foundation.

- Cleaned the mildew from the bottom of the wall really good.

- Run a de-humidifier.

Put a sheet of plastic between the stud and the basement wall to separate the fiberglass insulation from the wall. Although you have DryLock on the wall, moisture will still get through from these sources:

- There will be a small gap between the wall and the stub because the wall is not likely to be perfectly straight.

- Moisture from human "may" find its way through the drop ceiling to the back of the stud wall and reach the fiberglass insulation.

I am not sure how bad these sources of moisture can be. But I would much rather to use plastic sheet cover both sides of the stub wall to avoid any moisture from reaching the insulation material.

You may want to make sure the finished basement will have enough verical height after you have added drop ceiling and raised the floor. A low ceiling finished basement is not very appealing for the amount of work that you need to invest into finishing it -- you may get used to the low ceiling though.

Leveling the floor with leveling compound is the most difficult part of finishing a basement -- ignoring the issues of heating and cooling and electrical works. If you get enough vertical height in the basement, you may be better off using a raised floor as a way to level the floor instead of using leveling compound.

Good luck.

Jay Chan

[The Reverend Natural Light]

The humidity in the air will condense on the cold walls no matter how well things are sealed.

[Amun]

- Moisture from human "may" find its way through the drop ceiling to the back of the stud wall and reach the fiberglass insulation.

Not trying to criticize, just have laugh at what a spell checker must have fixed for you.

That brings us to a whole different moisture problem

AMUN