Heating a Basement – Good Idea or Bad?
user-22978
| Posted in Energy, Heating & Insulation on
Hi there – this is my first posting here so please bear with me.
I live in upstate New York and have a very damp basement which is also very cold in the winter. I am considering heating the basement, both to help dry it out (and perhaps make my dehumidifier work more effectively) and so that my hardwood floors on the first floor won’t be quite so cold on winter mornings (radiant floor heating is not a viable option at this time).
Question: I am concerned that warm and damp, as opposed to cold and damp, may foster mold. Mold would be worse than a cold basement. Anyone have any thoughts / experience with this?
Thanks,
Erik B.
Replies
Erik,
Welcome to Breaktime!
Before you decide if a change is necessary or to your benefit, you will need to determine a few things.
Is the basment damp from moisture entering it from outside (like ground water coming up from below and/or poor drainage)? If this is the case, solving this problem first is more important than heating the space.
OR does the basement seem "damp" because warm, moisture containing air condenses on the cool/cold surfaces in the basement. If there is no water seeping or leaking into the basement, heating the space will help keep condesation from occuring, but your energy bills will go up. If you have a forced air system, moving a little air through the space will improve the "feel".
Saturated or very mosit air at 55 degrees will be at less than 60% relative humidity if warmed to 70 degrees. This is still what I would consider less than ideal, but certainly better than 99% rh.
What type of heating stsem do you have? How is the basement constructed? Finished? Is there ground water seepage?
Thanks for the responses Tim and csnow, I really appreciate it. The (unfinished, cement floor, concrete block walls) basement is damp from water coming in from the outside - I believe from multiple sources. I believe I have a very high water table. In addition the soil around my house is very clay-like and there are spots in my yard where I can't dig a foot deep hole without it filling with water. Other spots, even at lower elevations, I can dig deep without any such thing happening. Its like there are little underground trickles of water coursing around my yard. The basement used to outright flood pretty badly. I had a French drain dug and some grading done, but I now realize that neither were done that well (French drain above the footing, not enough grading). I'm not quite ready to go through the trouble and expense of re-doing that yet. I also installed gutters. The combination of those things did make a big difference - the basement only floods on rare occasions and not nearly as severely as before, but its still very damp when it rains etc.My boiler and water heater got trashed in one of the floods, so they are now relocated to the first floor. I guess they used to throw off just a bit of heat, which is why the first floor floors seem so cold now.I thought throwing some heat down there might help the situation but you guys are convincing me that it probably makes sense to deal with the problem at its source first.Thanks again,
Erik
This is just my opinion, but I think you blew the chance to fix your problems when you re-did the french drains. If the new drains had been placed below the level of the floor, and the back-fill had been replaced with small rock, intruding water would hit the rocks, drop to the drains, and disappear. The low drains would tend to stop water perking up through the floor. You'd need to paint with a vapor barrier, and you'd have very dry basement. Add a dehumidifier and stiff insulation and you'd have a very livable space.It always kills me to see houses with fill against the foundation, as it guarantees dampness. Rock to allow drainage & a vapor barrier - works every time!
I hear ya. Unfortunatley, when I had the French drains done, I hadn't done my homework enough to know better. Intuitively, it seemed like they should be deeper, but the guy with the backhoe who was digging them assured me not. Its one of those "lessons"...
Thanks,
Erik
I do not think heating the space will make it significantly dryer. If it is wet in the winter, you have a very high moisture load coming in from the ground. Would be best to keep the water out in the first place if possible.
The 'stack effect' in the winter brings in cold dry air down low in the structure, and sends warm moist air out the top of the structure. If you have cold toes, this convection is already doing so much drying that adding a little heat to the process will make little difference.
Also heating the basement to get warmer floors is a very imprecise approach.
You would probably be better off insulating the floors instead.