mold problem!!!! built in Cabs

larry merlau

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Delton, Michigan
these are some drawers that i made and were built in to a knee wall with fiberglass insulation put on the walls and not in between the cabs.. and now 4 yrs later they are having this problem which has caused the drawers to swell up enough to restrict opening easily.. which lead them to the discovery of this:( any ideas on how to fix the problem?

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Ouch! That doesn't look good at all. I think the real question is where is the moisture coming from, if you solve that you solve the problem. I know you aren't going to like this (I know I sure wouldn't) but I think you'll probably at least have to either put a hole in the back there or pull that cabinet out to see whats going on. When you have mold you definitely want to nick it in the bud!
 
let them fix the water leak problem coming into the walls, clean out the mold then remake the drawers.

is that an attic wall, if so, Im doing the same thing in my attic bedroom right now, putting in drawers and doors in that space.
 
i dont think this is a water leak, could be but i think its just no insulation in the area between the drawer units?? and causing condensation there from the hating and cooling of the room
 
Any way to get back there and insulate/condition the space behind that knee wall? Unless you eliminate the source of that cold air you're always gonna have the potential for more problems just like this.
 
ted they insulated all around it, floor joist area and the short wall area,, the only place with insulation is between the two cabinets a distance of maybe 5" between the cabinets
 
What was used for insulation? How was it done? What is the vapor barrier? What is the room under this spot? Where is the dryer vent? where is the bath fan vent?
 
Looks like condensation building up on the glides and getting splashed on the wall when opened/closed to me. Is there any vapor barrier to kill the air flow around the cabs? Insulation isn't going to stop air flow and moisture from coming in and condensating on the metal. Can the units d be pulled out and put back with vapor barrier around/in the opening?
 
Looks like condensation to me. I'm wondering about air movement.

I've had this sort of thing in two houses now. In both houses there was a closet that ran along an outside wall. If we piled clothes up on the shelf right against the wall, then over the winter it would get cold there and you'd get moisture and mold. Our solution was to have an air gap.

Couple years ago I built a bonus room over the garage. It's well insulated, but still, it's over a garage, so it is not as warm as the house. While my daughters bed was being built I just threw a mattress on the floor right in the corner, an outside corner. After a month, there was mold growing on the baseboard behind the mattress. Again, the issue was that it was an outside corner, with no air movement.

Insulation in most(?) houses only slows the transmission of heat, it does not stop it. Here you've got an exposed area sticking out into the kneewall, so I'm betting that it's gradually going to get cold in those corners up against the insulation, and moisture will condense there which leads to mold. Is there any way you can get some air circulation through that space?
 
What was used for insulation? fiber glass
How was it done? fiber glass laid on the outside and stapled in place no vapor barrier
What is the vapor barrier?
What is the room under this spot? living room
Where is the dryer vent? oppsite corner of the house down stairs
where is the bath fan vent? bath vent is out he back of the house
 
Looks like condensation to me. I'm wondering about air movement.

I've had this sort of thing in two houses now. In both houses there was a closet that ran along an outside wall. If we piled clothes up on the shelf right against the wall, then over the winter it would get cold there and you'd get moisture and mold. Our solution was to have an air gap.

Couple years ago I built a bonus room over the garage. It's well insulated, but still, it's over a garage, so it is not as warm as the house. While my daughters bed was being built I just threw a mattress on the floor right in the corner, an outside corner. After a month, there was mold growing on the baseboard behind the mattress. Again, the issue was that it was an outside corner, with no air movement.

Insulation in most(?) houses only slows the transmission of heat, it does not stop it. Here you've got an exposed area sticking out into the kneewall, so I'm betting that it's gradually going to get cold in those corners up against the insulation, and moisture will condense there which leads to mold. Is there any way you can get some air circulation through that space?

where are you saying i need to get air flow art? in the attic area behind and around the drwer boxes or inside the drawer box itself art the drawers do not seal air tight from the inside
 
Even though it is insulated, the air behind the drawers is going to be much cooler because there is no airflow from inside. The warm moist air in the house seems to be condensing inside the case at the back where it is coolest. In essence, insulated does not equal warm. It's still an attic space with no heat circulated through it because it is sealed by the drawer cases. Ventilating the area with air from inside the house might solve the problem, but there would be a net heat loss. Insulating the back of the cabinets should also work, keeping the cold air in the attic from contacting the wood.
 
where are you saying i need to get air flow art? in the attic area behind and around the drwer boxes or inside the drawer box itself art the drawers do not seal air tight from the inside

I mean into the dresser. My closets aren't air tight either, nor was the mattress I mentioned... But having stuff right up against an outside wall leads to issue. I suggest an air gap of some kind. BUT, I admit that I don't know the best way to do that with a dresser built into a knee wall!

Even though it is insulated, the air behind the drawers is going to be much cooler because there is no airflow from inside. The warm moist air in the house seems to be condensing inside the case at the back where it is coolest. In essence, insulated does not equal warm. It's still an attic space with no heat circulated through it because it is sealed by the drawer cases. Ventilating the area with air from inside the house might solve the problem, but there would be a net heat loss. Insulating the back of the cabinets should also work, keeping the cold air in the attic from contacting the wood.

Rennie is saying pretty much what I was thinking. However, my understanding, Rennie, is that he DID insulate around the back of the cabinets, but not inbetween them. I don't think the inbetween would really be that much of an issue. :huh:
 
Pull the cabs and build a box around them in the space out of foil faced foam. Tape up the joints to complete the air seal. May want to use 2 layers of foam get it as close R19 or better. But you could get that with a stud wall done with fiber glass than covered with the foam.
 
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so if we done that chuck wouldnt that be making a wet box then rather than just the inside corners??

ok so we are saying we need air flow in the cabs right? what if we cut in soffit vent holes say 4" diameter to get some air but then that would take out the heat with it making a heat and cold air loss? what if we were to have spray foam on the boxes ? but we still arent gettin air flow but would be having better r value and direct to the cab boxes?
 
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If they have forced air heat where is the nearest vent? Close enough to tap into to force some air into the space behind the drawers? Air in low at one end and air out at the other end above the drawers to get some circulation the whole length of the space?
 
That looks like quite a bit of moisture for simple condensation. If the entire edge of the cabinet from top to bottom was wet I would think that was the case but this looks just localised. Is it on an outside wall and what is the siding used. No matter what you should not have any condensation inside the wall like that. Could there possibly be a leak inside the wall? Doesn't have to be big but with that type of mold growing you have a definite problem. That is the bad mold. I have had to deal with lots of homes in our area with similar situations. It always requires opening it up finding the problem and fixing it then getting in a dehumidifier and air movers to dry the area up. Any areas with black mold use a vinegar and water mix 1/3 and that will kill off the mold. If the wood is swollen it may need to be replaced.
 
Larry, Chucks foam box solution is what I would do, with two layers, and an air space in between, both layers sealed. I used this method in the home I am building now for my wife and I.

Most likely you have air movement carrying moisture laden air from inside the house, exiting in the back of the cabinet in a cold area. As the moisture laden air passes through the cold area the moisture condenses on the surface of the cabinet. Stop all air movement.

For an example of what air movement can do in a study on air infiltration a given wall section was built using conventional OSB/stud/fiberglass/drywall and was subjected to a given temp/humidity difference for set period of time. The same wall with one difference, a 1" hole was subjected to the same parameters.

The solid wall gained 1/3 Pint of water through permiation, water passing through the drywall. The wall with the 1"hole picked up 30 pints in the same time period! In other words air leaks can carry a lot of water with them, and permiation is of much less concern.

Gotta get to work....

The other Larry
 
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