Advice for Ventilating and Drying Cellar
Our cellar is quite musty and humid much of the time. it’s ventilated by open windows under the two closed and locked hatches in front and back (adequate for the boiler but it’s not much). We have three questions. 1. How do we get more fresh air into the cellar, such as via a purpose built vent or two, where would they go, what would such vents be, who would do this work? 2. What is the most simple dehumidifier option and what is involved? (We have no drain in the cellar floor, though we could potentially tap into the existing sewer line that runs above the cellar floor.) 3. We have what seems to be a new and increasing leak coming from the front of the house into the cellar from the floor, seemingly when it rains. I am slightly mystified because our front yard is paved (correctly) although we did put in a parch of garden close to the sidewalk about two years ago. Does anyone have any ideas? Thank you.
cate
in General Discussion 3 years and 11 months ago
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dorkofwindsor | 3 years and 10 months ago
I recommend a ceiling mounted dehumidifier, preferably one that can have a drain line empty right into a slop sink or other drain.
HRV is not necessary is nice, especially if your basement air mixes with your house air. It won’t act like a humidifier per se, but the air is tempered.
arewedoneyet | 3 years and 10 months ago
I would also recommend dehumidifiers – I run mine year-round and it cycles on and off as needed. I also have a french drain along the wall closest to the front wall where water occasionally comes in. Both the dehumidifier and the french drain empty into a sump pump which is piped to our sewer line.
nathanjoe755 | 3 years and 10 months ago
Thanks for this! I am going to buy 2!
shahnandersen
in General Discussion 3 years and 10 months ago
I assume you don’t have a floor drain into which you could continuously empty your dehumidifier into instead doing it of manually. If your sewer line runs above the cellar floor the ideal solution was to get a dehumidifier with a built-in pump to remove the condensate. But since you already have the dehumidifiers, you could get an accessory condensate pump such as https://www.amazon.com/Little-554425-VCMA-20ULS-Condensate-Removal/dp/B000SM342Q/ref=asc_df_B000SM342Q/?tag=hyprod-20&linkCode=df0&hvadid=198079373928&hvpos=&hvnetw=g&hvrand=17145891343175830262&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9004356&hvtargid=pla-349148507253&psc=1 to automatically remove the water. No more hassles.
nathanjoe755 | 3 years and 10 months ago
Hello! I posted a while ago about the insane amount of mold in our cellar. We’ve bought and put in two dehumidifiers which we have to empty 1-2 times a day right now (in the winter it hardly runs). It is a hassle but works as I try to save money and figure out a long term no-fuss solution. It really really helps knock down on the musty smell. I can tell when they are full and not running from the smell.
hkapstein | 3 years and 10 months ago
I agree that the source of the moisture should be identified and addressed, but if you wanted to ventilate the cellar, and I think it’s not a terrible idea, I’d considered installing an ERV or HRV, ducted to the outdoors, probably your backyard. Ideally you could get the intake on one side of the cellar, and exhaust on the other for a cross ventilation. The unit uses a heat exchanger to minimize the energy loss from from operating it.
One common source of dampness is when the air in the cellar is warmer than the floor or walls and condensation occurs leading to slab or floor that is always damp. In addition to a moisture barrier, it probably a good idea to install an inch or two of rigid insulation underneath when pouring a new slab, although I don’t often see this done or recommended.
workisfun | 3 years and 10 months ago
Have you considered a sump and pump? That could solve your flooding if the pitch in the floor is good.
workisfun | 3 years and 10 months ago
I’ve had several waterproofing contractors and engineers refer to the hydrostatic pressure in general and particularly in BK. The soil is so dense here that excess rainwater is forced up to the surface, even seeping through concrete slabs. That’s where perimeter drains come in. They present a managed point of least resistance for the water. We also run a couple dehumidifiers in our half-in-ground level. They run a lot. Not once a week. One is emptied manually. The other drains via gravity into the W/D drain.
cate | 3 years and 10 months ago
This is incredibly helpful all. Thank you so much!
Guest User | 3 years and 11 months ago
Oh yes she mentions the floor too. Sorry about that.
The front wall is the area I was referring to when I said waterproof from inside. However this would only help with the water coming in from the front.
Guest User | 3 years and 11 months ago
She said it was coming from the front yard not floor. Unless I misread. Either way though agree, should talk to waterproofing expert. They are going to be able to see the real thing and assess better than us.
shahnandersen
in General Discussion 3 years and 11 months ago
If the water is coming from underneath the cellar floor there is no way to waterproof it from the inside, unfortunately. Not sure that waterproofing the foundation wall would help either. You need real on-site help from someone who knows what they are doing (waterproofing contractor?, Engineer?) Good luck.
Guest User | 3 years and 11 months ago
Cate, you may be able to waterproof inside if the bluestone is an issue outside. It’s not the best solution but you avoid digging up the bluestone.
shahnandersen
in General Discussion 3 years and 11 months ago
We had lots of floods, but those came from backups and construction next door. The water did come in from floor rather than through the party wall. Fortunately, that is over now. The floods never damaged our dehumidifier. In any case, you can just put it on a couple of concrete blocks. No need to pour a permanent fitting,
We now have a few wet spots on our cellar floor but no standing water, which I attribute to a rising water table. But the dehumidifier prevents the air from being musty (nor my tools from rusting).
cate | 3 years and 11 months ago
Our cellar sometimes floods, so prob best not to put the dehumidifier directly on the floor? We prob will need to waterproof the front first; pavement is already sloping correctly; perhaps the garden can be dug up and part of it lined or something. We just put in bluestone paving at great cost so digging that up would not be optimal. The wall is not leaking, though I highly doubt it’s waterproof. The water is coming up through the ground.
shahnandersen
in General Discussion 3 years and 11 months ago
Not sure why you would need a concrete footing for the dehumidifier. They weigh less than 50 lbs and the pump will raise the water output 12 feet. In our cellar, we have a washer/dryer on its own circuit which we also use for dehumidifier which we turn off when we do the wash to avoid the potential overload. (Note that the item I mentioned has sold out but lots of similar models available for $250-300).
Guest User | 3 years and 11 months ago
in my experience hard to find one person for venting and pump but you may have luck with a company that does hvac and plumbing. If it’s only a pump, plumber should be able to handle and they may have an electrician they work with.
Waterproofing is typically separate. Regarding water issues in front, Water is going to get pulled down by gravity so sloping the front yard away from the building is important. In my experience most GCs are not good at waterproofing and mine didn’t want to do it.
You can waterproof from outside, dig down a few feet in the front and waterproof the front. Should only take a couple of days. You want to do it when there is clear weather and then wait for rain to see if it’s working. If front wall is brick, you can also try to open up the wall and try to do it inside.
I understand dehumidification is a good idea if it’s mild. Might be worth to to make sure the water issues can be fixed at source or if it’s fairly mild, then continue down the path of
getting a dehumidifier. With climate change, the weather patterns are only going to get more aberrant. Rain and snow will be much heavier.
cate | 3 years and 11 months ago
If we do install a dehumidifier with a pump, we will potentially need to put it on a raised concrete footing, put it on its own electrical circuit, and tie it into the plumbing system. Do basement waterproofing or HVAC companies or plumbers sometimes handle the whole thing for homeowners or do we need to arrange all the trades separately? Thank you.
cate | 3 years and 11 months ago
Thank you bobjbkln!