Recenlty I found that we have a bit of a mold problem in the house. Nothing too drastic but i want take care of it asap. Seems to be more in the back bedroom and a bit in the masterbedroom.
First a bit of background on the house….
Location: central Mass.
House age: 1950s capestyle
Here is the kicker…. slab on grade foundation.
Gutters: Yes
We bought the house 2 years ago and revonvated the inside (downstairs only, attic is unfinished).
Recenty noticed that a nylon camera case i have appeared dirty, only to realize it was MOLD. upon further inspection we found more of it in the closet, on our shoes that we may not have worn recently. The mold was a light green color, not the black stuff you usually find in the bathroom walls from a tub leak or whatever.
Both bedrooms have carpeting in them. Newly installed when we renovated.
So far i have put a dehumidifier in the office/ back bedroom to help.
My next step is to take up the carpeting and seal the floor with some Drylok paint.
Any thoughts & suggestions would be greatly appreciated.. Thanks
Ray.
Replies
If you really want to get those little mold bugs you have to do this, which an old-timer taught me: take the shoelace off your shoes and hold it really close to the floor, not quite touching the floor. Pull on the ends so the string is taught. Wait for the unsuspecting mold to wander by and when he trips on the string, WHAM! Stomp him with your foot.
Aside from that, the dehumidifier is a good idea, and the Drylock certainly wouldn't hurt. Some other things to think about-- I've often used louvred doors on closets on slabs to promote air circulation. Make sure you use your bathroom and kitchen fans every time you use the stove or the shower. Don't use a ventless gas fireplace.
And keep a shoelace handy.
Mold like this tends to happen where there is poor ventillation, and the area is for some reason cooler than the rest of the house (eg, because it's on an outside wall).
Improve ventillation: Sometimes just shortening the door at the bottom will make a big difference, other times you may be able to find a nearby heating/cooling duct you can tap into to generate some airflow.
Try to determine why the area is colder: There have been cases where an interior closet backed up to a plumbing chase that was open to the attic, causing the mold problem and costing heat as well.
Run a dehumidifier if necessary, but usually this isn't needed if the other details are covered.
The mold appears to be coming up from the concrete slab floor that is under the carpeting. even though the carpeting is some what new there are some spots like under the bed that if you smell the carpet seem to smaell a bit musty.
for a bit more info there are tupperware containers that we keep under the bed that have seasonal clothing like sweaters and gloves, ect. The container that has my winter gloves, ski goggles and the like has mold in it. which i found to be odd.
how the heck is the mold getting inside of the container???. I realize that the container is not air tight, but i figured the items inside mide be sheilded away from the dust and other things that the mold may be able to feed on.Thanks for the reply.
Ray
When you seal the container, is it full of dry air, and no mold spores?You might try adding a package of desiccant.
If moisture seems to be coming up from the slab, consider the possibility that a water pipe is leaking under there.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
The mold isn't coming up through the floor. The mold has been in and around your house forever. It's just permitted to grow there because of the conditions. You have a microclimate in your closet that permits it to thrive whereas those conditions don''t exist in the rest of the house.
Wipe your shoes off, clean the closet, use a dehumidifier or one of those small heating elements they put in pianos. The mold will still be there, it just won't be as noticeable, just like the rest of the house for the last 50 years.
I'ts not the mold coming through the floor .
I know that. Since mold usually needs moisture to grow i figured that the more likely spot would be the slab.Get rid of moisture and you don't get mold. so thats what i'm trying to do.
as best i can.Thanks for the input
Ray
To find out if moisture is really coming up from the floor you can do the following:In an out-of-the-way place, pull back the carpet and apply a piece of plastic directly on the concrete slab. Cut the plastic sheet about 6 inches square and tape it to the concrete floor with masking tape. Re-examine the plastic after 24 hours. If there's moisture on the bottom of the plastic then it's got to be coming through the concrete slab. You could also just use a moisture meter to do the same thing.
It's probably warm moist air condensing on the cool or cold slab. Is it worse in the warmer months? I've run into that same situation before. Usually because the slab isn't insulated and so essentially the slab will be about the same temperature as the earth, probably somewhere in the high 50's. When that meets the warm MOIST summer air condensation is inevitable.
Also sounds like the slab was poured without a 6 mi vapor barrier.
Based on the age of the house I doubt that they did a6 Mil poly before pouring the slab.The strage thing about this problem is the other houses in the neighborhood are built the same way and I have not heard of others having the same problems.Thanks for th input JoeRay.
Have you checked the ducts? If you have forced air HVAC, the mold spores may be spreading when your HVAC kicks in.
We have baseboard water with and oil burner for the heating system,
Though a vapour barrier may act as a capillary break for the slab foundation another important part is the layer of gravel under the slab which allows water to drain away and maintain a separation. As I understand it the vapour barrier under the slab's main purpose is a radon barrier not as a capillary break.I think your problem is likely as others have mentioned condensation. You could look into using a drycore system to have a separation between the slab and your carpet, rather expensive but cheaper than fixing the problems with your slab.
Sounds like a good idea.
Do you think i should still do the drylock even if i do the drycore floor??
It probably could be moisture coming up through the slab, but I just bet its mainly condensation. That plastic patch test won't really tell you any thing because it will get wet regardless, thats actually an old boyscout trick. If your lost in the desert and you miraculously happen to have a container and a peice of visquene you put the plastic over the container with a rock in the center of the plastic to make it sag and viola condensation occurs and you make water. Anyway thats what would happen wether or not moisture is seeping out of your floor.
Mold needs three things to grow: moisture, air, food source. Get rid of one and its gone, however the millions of spores only spread when they're dry so once you kill it it can still be a problem. You might want to sell the house. I'm not freaked out about the huge health risks that mold poses, but there are many documented cases of people developing serious allergies as a result of extended exposure. As a matter of fact I personally Know someone who had EXACTLY the same story as you. They were renting the house for about a year with identical mold problems. A little while after they moved out his healthy wife developed severe asthma which she still has.
The plastic test will tell you which (under ideal conditions) because condensation will be on the top if it's from above, on the bottom if from below. The iffy part is how wet the slab is from prior condensation when you start this test.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
I think dryloking the floor is a good precaution where you don't know the status of the slab and if it was built in the 50s then it is probably a good idea. The only issue is that if the floor has cracks you first may need to parge the cracks and then apply the drylok to the floor after you have cleaned it. In the case where you are pulling up your carpet and installing the drycore system I would go to the extra effort to drylok the floor as you are already doing a lot of work and it wouldn't be all that easy to drylok after the fact. Seems the extra risk for the drylok is small compared to the risk that moisture is coming up through the slab.
I probably will do the drylok paint, now that may slove some of the problem.
If the rpoblem is more of a condensation thing than what can i do to ward off that problem.I did have a thought of using the drycore floor panels then some laminate flooring.
or maybe some thin rigid board insulation then plywood and some laminate or harwood flooring.Any thoughts ??Ray.
I'd go for the drycore approach. The insulation is a good idea but I'd sway away from it because it would be harder to install properly. The drycore provides airspace to allow the moisture to evapourate where as the insulation wouldn't have that airspace so a proper install would involve sealing the insulation and ensuring that no warm air got underneath it to condense, on top of that if the drylok fails and your problem was with the water coming up through the slab then your insulation will be sitting in a pool of water.Good luck let us know which approach you take and how it works out for you.MG
The only thing that has a bit of concern with the Dry-core sub0floor route is the hieght if the new flooring once allis said and done. I have'nt looked at the Dry-core lately so i don't remember how thick it is.I still need to do the plastic test to check if the moisture is comin ghtrough the slab or condesing on top of it.Might gut says to Drylock the concrete and porbably still do the Dry-core sub-florring, then maybe a laminate flooring instaed of carpeting..... so far just a thought..Thanks for the input, i'll keep you posted as this sitiuation developes.
I sure hope that whatever I do I can nip this thing in the but before it goes too far.Raymond.
Guess I missed something here, what is drycore system? Read the previous posts twice and still missed it.
The plastic test should tell you whether moisture is wicking up through the slab or condensing on top. Of course slab could be wet from previous condesation, conditions for condensing might not be right at time of test...
If condensation is the problem, I think styrofoam might help. Expensive, but not difficult, and who wants to live in a mouldy house?
You could put poly moisture barrier on the concrete, styro, then screw down plywood with tapcon screws. This should allow the surface to stay warmer, eliminating the condensation.
Good luck.
Of course, cheaper, simpler solutions are to slightly improve airflow (cut bottoms off of doors, eg) or keep the area slightly warmer (with a small wattage lightbulb burning all the time).
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
Some one else had suggested that as well.
First , at the present time there is no door on the back bedroom
so i doubt there is a problem with air flow. and as far as putting a light bulb on to keep the area warmer , it's not just the closet that has the mold (although the greatest concentration of it). it has appeared on items in the room itself but not everything which seemed strange.
It may be that there is not a plastic vapor barrier directly under the slab - which I assume is the reason you want to Dry-Lock the slab surface. Is there a utility room, etc, that does not have finished flooring (carpet, etc) installed? If so, take a 2'x2' piece of "clear" plastic and tape it down to the slab. After a few days do water droplets form on the underside of the plastic? If so, moisture is definitely coming up through the slab, probably due to no vapor barrier under it.
Now a few Qs:
Does your kitchen hood vent to the exterior?
Do your full baths have fans that vent to the exterior?
What other sources of moisture/vapor is there in your home?
Do you have a gas or other combustion device within the living space? If so, have it checked for proper (clean burning) operation and check the flue(s).
You said you have gutters - do the downspouts have extensions on them to ensure that the water is deposited well away from the foundation?
Take a probe rod or something similar and probe the ground about every foot or 2 around the entire perimeter of the home. Are there any saturated areas? If so it could indicate a plumbing leak or underground spring, or maybe just poor drainage and/or grading.
Ihave not tried the plastic test on the floor to confirm that it is the slab that is causing the problem. But i'll give it a try.
I'll just have to do it in one of the bedrooms , these are the rooms that seem most effected.To answer your questions
The rage hood does not vet to the outside. it's on an inside wall.
the down spouts do have extensions, but the one in the back is not that long.
The problem appears to be worse in the warmer months, (so i think)
Asfar as broken pipes I can't say for certain but I don't see my water bill getting any higher due to higher water use from the broken pipes.The grade around the house is not too bad but the side of the house is pretty flat and there is not much grass growing there. The last major rain storm there was for the fisrt time (So i think ) there was some standing water. There are a lot of trees along the border of my yard and the neighbor's yard. all of 12 or so ft away (small yard) that stop the sun from really drying out the that area if it gets soaked.Granted i think the yard needs a little help with the grading and drainage.
But do you think that the drylock paint and possible digging a trench around that side of the house and adding som drainage pipe (to be sent to the back yard would help.The other question is ,once I take up the existing carpet to put on the Drylock, shouls I not use carpet agian? If not what? Laminate maybe?Thanks for the response MattRay