Working Around Old Basement Framing

pressureseal · 01-15-2008, 06:25 PM

I have a project underway to redo a couple of rooms in my basement. The house is from the early 70's and is basically new to me.

Since I am happy with the current layout of the rooms, my plan was to rip down the old walls (cheap panel board) and just replace it with drywall. I would like to keep the existing wall framing to keep costs down.

Well after taking out the old wall panels, I am finding that things don't exactly match what I have been reading about for basement framing. The framing was put up directly against the concrete foundation with nothing in-between. Stuffed in the gaps is insulation but again with nothing between it and the concrete foundation. The insulation and framing was covered between the wall panels with some sort of paper? and then plastic but the plastic was not sealed air tight.

The sites I have seen on basement framing say you need to put insulation and plastic down behind the framing but it is obviously too late for that now. I don't have a lot of experience with this sort of thing but can I just cover up the existing insulation/framing with vapor barrier on the inside and seal it air tight?

ToolGuy · 01-15-2008, 07:02 PM

Yes, you can. It's standard practice to frame directly against the foundation wall, or even use furring strips attached to the foundation wall as framing. If you look through some of the recent topics here in these forums you'll see it's been discussed quite a bit recently.

The insulation is probably paper-faced fiberglass, a standard building material. Unless there is moisture damage or anything of that sort, you're fine to just leave it alone. Replacing the vapor barrier is a good idea. 4 mil polyethelene is commonly used and available at any hardware or paint store. It's more commonly known as plastic painters tarps. You can get it in 9' x 12' sheets, 10' x 25' rolls, or many other dimentions.

I'm sure others will be along soon to add to my input, or possibly to correct me on some parts of it.

Welcome to the forums and feel free to ask all the questions you may encounter. It helps keep us on our toes.

pressureseal · 01-15-2008, 07:48 PM

I don'[t mean to second guess you, but .. are you sure I don't need back vapor barrier or something by the foundation?

Believe me, I am truly hoping the answer is yes as this would save me considerable expense and effort.

The 1 thing I didn't mention is that there is some browning of the insulation (it is fluffy fiberglass) which I'm thinking might be moisture related and/or mold. Would you replace the insulation in that case?

Also, when I took the base boards off, I found black mold between the base boards and the wall board. Not sure if it is 'the' black mold just that the color was black. I promptly got the base boards and wall board out of the house of course.

There doesn't seem to be any mold damage to the actual framing so I don't think I need to worry about that but I am just concerned what will happen if I vapor barrier it in. Am I at risk of getting water in the framing/insulation? Also, should mention that the mold was only present behind the baseboards along the exterior walls.

ToolGuy · 01-15-2008, 11:10 PM

It sounds to me like there has been water in that basement. You can clean up any mold with bleach, which kills it on contact. I've gone around with a garden/pest sprayer and sprayed the bottoms with a bleach water solution, just to get rid of moldy smell.

You want the vabor barrier between the drywall and the insulation. That's how it works. The vapor barrier is to prevent moisture in the interior air from reaching the cold surface of the foundation wall and condensing. If the barrier is behind the insulation, the barrier itself would get cold and collect condensation from the interior air.

If there is moisture comming in from the outside, that's a whole different ball game. The only way I know of to fix that is from the outside, meaning it has to be dug out and waterproofed - no small task by any means.

Maybe someone here knows more about moisture coming from the outside, but as for vapor barrier, it goes between the drywall and the insulation.

inspectorD · 01-16-2008, 06:12 AM

Heyyy and welcome aboard.
Well he got it half right.

To make it simple...you install the vapor barrier to the HEATED side. If you live in Florida....that is on the outside, and not plastic...unless you want decay.

The issue with basements being finished is a complex one.
First if you have any water coming into the basement....you need to fix that first. Just like if you had water coming into the exterior wall upstairs, you would not sheetrock until that is finished.
Then you need to remove ANY mold which I am sure you understand fully.
Do not install plastic over any wood against the foundation, it will trap the moisture and rot the studs.
Check out www.buildingscience.com for more info and check out the digests on basements....then ask us some more about finished basements. This way we are on the same page. And you learn much more than I can type......

ToolGuy · 01-16-2008, 05:44 PM

See? Told ja so.

inspectorD · 01-16-2008, 06:32 PM

The reason I learned that was when I was in Las vegas for a convention....there was a topic on modular homes in Texas getting serious mold issues. The problem was they where built in PA by cold climate carpenters. The A/C was rotting the building because the plastic was on the inside.

EEEEEEEWWWW was the end result......with various lawyers spread about.

pressureseal · 01-16-2008, 09:43 PM

Okay, thanks for the link, the site is well .. very informative. A little overwhelming almost but exactly what I needed.

Reading through some of the water diagnostic papers it sounds like it may be a problem with moisture in the air condensing onto the interior surface of the walls, and then getting in behind the baseboards. Perhaps the water vapor is attracted to the baseboard area because the vapor barrier was not sealed tight and hence there was some minimal airflow into the colder walls. The baseboards were not sealed airtight so this seems possible. Should also mention that I live in a cold climate, so most of the time the basement is going to be warmer than the outside leading to condensation against the walls, perhaps? Does that sound possible? That is the best theory I can come up with but I have to admit it does seem a little strange.

A couple points to support this theory are that the interior walls (that is walls in the interior of the basement not adjacent to the foundation) had zero mold so I don't think there was flooding in the basement. Also, the framing itself looks solid without even any water stains so I don't think water in liquid form was actually making it's way down.

Could anyone comment on whether I am on the right track? It seems very important to figure out which way the water is coming, inside vs outside as if it's coming from outside I don't want to just vapor barrier the inside as I think I would be just trapping the water in the framing.

ToolGuy · 01-16-2008, 10:05 PM

You're definately on the right track. That makes sense about moisture running down to the baseboards, thus the mold but not water stains.

What transpired here is, in a nutshell, that warmer climates shoud have the vapor barrirer on the exterior side of the insulation, while colder climates should have it on the interior side of the insulation. So in your cold climate (mine too, chicago), the vapor barrier shoud be between the insulation and the drywall.

I did some Googling and found this good example..

http://eiktaylor.wordpress.com/2007/07/05/a-rant/

inspectorD · 01-17-2008, 06:10 AM

The thing you need to remember is this, you are on the right track.

The site helped you more than you know. You also need to remember this is a basement, you need to not use plastic for vapor barrier, it causes many issues when you change the dynamics from what you had.
Installing an insulation board against the concrete wall will do the best job of slowing vapor action. The thicker the better. The water vapor enters the basement by capillary action,not always visible water. This collects on the plastic when it reaches the dew point, like a cold soda on a hot day. Then you end up with water at the base of the wall and anything organic cellulose in nature will absorb it. Wood, dust, paper ...it's deja vu all over again, mold grows.
I like to keep that material expecially carpets out of basements.

The institute of building construction technology www.eeba.org has done extensive testing on these subjects , this is another avenue to educate yourself....if you want to do it right check out the building science books for your area. They have extensive drawings and details on the entire home. Thase books are a must have for anyone working on homes or just want to know more.....with pictures. I have the cold climate book, it is my bible so to speak. It is worth every penny.
These are my opinions, you can do it right once....or correct it for a long time.
Keep reading, even go back and reread the site. You are on a good track. That basement isn't going anywhere.