I cleaned my basement floor with bleach & water after finding a white fluffy substance directly around the furnace on the basement floor (concrete). I then painted the floor and the paint is bubbling in that area because the white fluff is coming back under the paint. I do not get water in the basement and this fluff is only in that area. What is this and what is the solution?????

Lizzy

 

I don't know what the solution is, but the problem is caused by moisture underneath the slab of concrete that is coming up through the concrete. The moisture as it goes through the concrete causes the powder to form on the surface. In some cases, it causes the concrete to start to break up on the surface.

I had this problem, and I just ignored it and it went away eventually. Luckily it wasn't in a spot that anyone took notice.

I'd call one of those companies that specializes in waterproofing basements, plugging leaks in foundations, etc ... and see what they have to say. If there is a way to fix it other than digging up the concrete floor and putting in drainage tile, let us know.

 

Look at your local hardware store for a can of "Killz" (spelling?). It seals things like cement against moisture, and will allow you to paint over it and over previous mold/mildew problems. You will probably have to strip the paint from the area first, but ask to be sure!

 

Regular paints won't work well on concrete. Use a paint made for concrete. An epoxy paint would be better. Follow the directions on the can.

But lets try to figure out the moisture issue first.
Did this "white stuff" just start appearing or has it been around for a while?
How old is the house?
Do you have a sump pump? Has it been running a lot lately?
Does the furnace have AC on it? Does that drain correctly?
Have you had a lot of rain and/or snow this year?
Have you noticed any problems with drains in the house?

 

Bob,

My house is 28 years old. The paint I used was recommended for concrete floors (oil base). The paint worked very well in the remainder of the basement. The problem was there before I painted probably 6 months or so. I do not have a sump pump or air conditioning (we have forced air heat). The furnace is in the middle of the basement (where the problem is). The only thing I can think of is that we took the rain gutter down to paint and haven't put it back. The eaves on our house come out about 2 feet all around the house (hip roof). I thought that would direct the water away from the house. The guy at the hardware store told us there is nothing easy that you can do about this if the gutters do not help. Any other sugesstions?

 

Yes, it could be lack of gutters that is the root of the problem. There is water under your house that wasn't there for the previous 27 years.

Put the gutters back on. If possible, drain the water far away from the house.

Landscaping can also effect water in the basement. The yard should slope away from the house.