I just moved in to a one story home that was built in +/- 1950 with unfinished basement. Although there is a drainage tile around the perimeter of the foundation and two sump pumps the basement feels moist and smelly. I purchased dehumidifier and it reads most of the time 80% humidity level. humidifer works 24/7 if set at 50%. I do not think that there was a vapor barrier installed under the slab as it seems that floor is where the moisture is coming from. Is there any kind of coating that can be applied to slab to prevent vapors entering basement and rest of the house? First floor shows 60% humidity.
Any advice would be appreciated.
Replies
Dehumidifier is the way to go. You probably have it draining into sewer so you don't need to empty the bucket manually.
Two sump pumps? How often do they cycle? Do they run contiuously? Are they deep enough to take the water away from under the slab? Is there an area of the floor some distance from the sumps that appears wet? is it possible to add another sump in a problem area?
What I am sayin Bob, you want to get the water away from under the slab. If you are sitting on a spring or you have a basement that floods seasonally, there isn't alot you can do to stop it.
One of my homes had a stream running across the basement every spring. The former owner had carved a trough in the slab to contain it and carry it to a drain. There was nothing I could do other than paint the slab and walls to keep the moisture at a reasonable level. I was never able to finish the basement so I built some shelvng to keep storage off the floor an used the rest of the space for a workshop.
Thanks for response.
There are no wet spots or visible standing water anywhere in the basement but when touched some places seem more moist. Pumps are sitting on top of cmu blocks in their pits approximately 8" inches below top of the slab and go off only once or twice during a day. I tried lowering one pump yesterday and then it worked almost continuously therefore ground water level is pretty high and there is not much I can do about that. I am thinking about painting basement slab with epoxy for garage slabs sold at Home Depot and keeping pumps as they are. My main concern is humidity entering the rest of the house.
There are some product that "react" with the concrete are suppose to waterproof it.
Zerpex or something like that.
Hopefully that will trigger someone else to give the right name or that has used it.
I'd lower that pump and let it go for a day or so to get as much water away from the underside of the slab as possible. If it starts to cycle again, leave it there. Put some fans in the basement with maybe one in the window to dry off the top of the slab. I probably wouldn't use the epoxy just regular floor paint will do. They have latex floor paints if you are worried about off gassing or getting stoned while applying.
I finished an indoor swimming pool a while back and was suprised at how well a single dehumidifier controlled the moisture. I think it cost them a couple hundred bucks plus plumbing. An air exchanger, heat sink etc. to handle the area was around 15 grand.