DIY Home Improvement Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
I would like to cut gaps in my basement drywall to allow moisture to escape and not cause mold or water damage. When my house was renovated last year, the crew ran the drywall all the way to the basement floor (tile over concrete) and all the way up to the ceiling. Now I am seeing brownish water stains on the drywall near the floors and in the corners - and in some small patches there appears to be mold.

To fix this, it seems to me that I should cut gaps of 3/4" along the bottom of all the drywall where it meets the basement floor. But how can we make these cuts and get a nice, clean edge? What sort of saw or knife would we use for this?

And should I install a gap near the top to allow moisture to escape near the ceiling?

FYI, this is for a 100-year-old attached townhouse in NYC.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #2 ·
Another question, further to the above: It occurs to me that the renovators probably put wood beams (2x4s?) at the base of the walls behind the sheetrock. If that's right, and if I cut a gap for moisture, the gap would have to be high enough to clear the wood beams. But will the wood beams continue to be a problem? Or will a gap that clears the beams and opens the space behind the drywall be sufficient?
 

·
Registered
Joined
·
12,832 Posts
Cutting the ventilation opening that you describe sound like a bad idea. For most finished basement walls it is important to air seal the walls to keep humid basement air from reaching cooler basement walls.

The really bad news is, the moisture issues should have been resolved before the drywall and whatever is behind it went up. The moisture you are seeing is probably not condensation but leakage from the outside, just a guess.

And I have no easy solution to offer, sorry.

Bud
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 · (Edited)
Thanks, Bud. What do you recommend? Ripping out all the drywall and adding some sort of sealant to the foundation?

And if it helps, a modicum of moisture in the air is OK. This basement is for storage and laundry only. My thinking is that it is better to allow the moisture to circulate through the basement instead of being trapped inside the wall.
 

·
retired framer
Joined
·
47,060 Posts
Might be time for some exploratory surgery to see what is going on, there could be mold in the wall. Insulated? with what?
Outside this spot, downspout? Landscape slopes away from the house? Dirt level high on the foundation?
Type of foundation?
 

·
Registered
Joined
·
12,832 Posts
Managing basement moisture if difficult in new homes but in a 100 year old house it is almost certain they were not concerned.

Before the drywall was put up were you there long enough to know about any water issues? Often times water issues originate from landscaping problems. Drain the runoff farther away from the foundation and none gets into the basement, sometimes. Other times it is a ground water issue, difficult to change.

Do you know what is on the walls behind the drywall? Studs, insulation, vapor barrier?

Any rain water pooling against the foundation?
What king of material is the foundation made of, concrete, stone, brick?

Bud
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #7 ·
Bud and Neal, some more info:
--I believe the foundation is stone.
--I do not know what is behind the drywall, as I bought the house after renovation.
--Basement is entirely below grade (next floor up is at ground level).
--The only pooling water came during a massive rainstorm and seemed to come through the floor, but even that was just some shallow puddling; the moisture in the walls seems to be much less.
--The house is on an incline, and most rain water seems to run past the house downhill and down the street.
--Only the front and rear walls (about 17' wide) are exposed to the outside; on the sides (40' long) are the basements of my neighbors' attached houses.
 

·
retired framer
Joined
·
47,060 Posts
Bud and Neal, some more info:
--I believe the foundation is stone.
--I do not know what is behind the drywall, as I bought the house after renovation.
--Basement is entirely below grade (next floor up is at ground level).
--The only pooling water came during a massive rainstorm and seemed to come through the floor, but even that was just some shallow puddling; the moisture in the walls seems to be much less.
--The house is on an incline, and most rain water seems to run past the house downhill and down the street.
--Only the front and rear walls (about 17' wide) are exposed to the outside; on the sides (40' long) are the basements of my neighbors' attached houses.
Is the floor exposed concrete. Any patching exposed?
No sump pump or anything? Do you think the floor might be new with the finishing of the basement.
 

·
retired framer
Joined
·
47,060 Posts
Floor is tile (probably new with the renovation), and I assume below that is some very old concrete. No sump pump.
If you had water pooling on the floor, water finds the easy way and likely came in from the edge, it would follow grout lines and leave tile looking dry as it went to a low spot.


So you have one of two problems surface water leaking thru the wall.
Ground water under the floor to high. The fix for both is about the same and ugly. A small flood like that every few years might not be more than a few minor repairs.


I would want open a little drywall in the corner and see the condition and moisture content in the framing at the bottom of the wall and see if water is still coming.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #11 ·
Thanks. I can easily open a discrete spot to check for moisture and what's behind the drywall and then re-seal it.

Putting aside the leaky floor possibility, what do you see as the repair options for the wall, depending on what I see when I open it?

(And I'm assuming you agree with Bud that opening ventilation/drainage gaps inside the drywall is not the solution.)
 

·
retired framer
Joined
·
47,060 Posts
Thanks. I can easily open a discrete spot to check for moisture and what's behind the drywall and then re-seal it.

Putting aside the leaky floor possibility, what do you see as the repair options for the wall, depending on what I see when I open it?

(And I'm assuming you agree with Bud that opening ventilation/drainage gaps inside the drywall is not the solution.)
Warm moist air getting to a cold concrete wall will cause condensation and possibly more problems.


I would take little drywall right at the floor where it is wet maybe six inches high, If the drywall is really wet inside and the wood is wet then you may want to continue until you get to dry. With the tile holding water back the bottom of the wall could be sitting in water.
 

·
Usually Confused
Joined
·
7,575 Posts
Liquid water incursion can only be effectively controlled from the outside, a fairly expensive and disruptive undertaking. It is highly doubtful a 100-year old stone foundation is properly waterproofed but you have no history since it was covered before you moved in. Condensation moisture can possibly be managed through airflow and dehumidification. The wall finishing could be trapping moisture and moisture (condensation) could also be coming up through the floor.
Regardless, cutting slits in the wall won't cure your problem, particularly if the wall contains insulation. Since it is just used for laundry and storage, you might be farther ahead to rip the drywall down. You could leave the framing up but you might find it is compromised as well. Mould can become a serious health hazard.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #14 ·
This is all very helpful. Stripping off the drywall from the two exterior walls (front and back) seems likely the way to go, depending on what I find when I check the insides.

And depending on what I find, hopefully I can leave the drywall on the two non-exposed walls, since on the other side of them are neighbors' basements and not wet dirt.
 

·
retired framer
Joined
·
47,060 Posts
This is all very helpful. Stripping off the drywall from the two exterior walls (front and back) seems likely the way to go, depending on what I find when I check the insides.

And depending on what I find, hopefully I can leave the drywall on the two non-exposed walls, since on the other side of them are neighbors' basements and not wet dirt.
Let's see what you find first.
 
1 - 15 of 15 Posts
Top