rock foundation basement

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rock foundation basement

Post by Tracey »

I love my house built in 1880, but I hate the basement. The smell makes me gag. It is a rock foundation so the moisture is alway there, even with a dehumidifier being used. I have been told there is nothing I can do about it. We can't store anything in it because the moisture ruins everything!!!! We even have plants growing in it. Is there anything at all that we can do? We would greatly appreciate some suggestions. Thank you.


Re: rock foundation basement

Post by farmgirl »

Hi- I am wondering what is causing your basement to "smell"? I live in an old stone house, and while my basement is not the Sahara, it doesn't make me gag! How are plants growing in the basement? Are there lots of windows? I think your problem may be grading to make sure water is not running toward the foundation, but away from it. If it is really bad, you may have to look into some sort of tile drainage field around the house. I am no expert, but your basement shouldn't be THAT bad! Good luck!


Re: rock foundation basement

Post by Bry »

Yikes, it does sound nasty... I had a similar problem with mine, but fortunatly some major causes of damp aren't expencive to fix.

First, you should stop using the dehumidifier, all it does by removing damp is make the walls wick up even more water. In fact it can speed up the deterioration by drawing a lot more water through the stone. Keeping a window open a few inches should be quite enough in a normal basement.

Also, now would be a good time to check your guttering for blockages or leaks as these can deposit a lot of water in the ground next to your house. It is also a good idea to install downspout extensions as these help remove water from the area of your house. If you don't like normal extensions (I hate the look of them myself) you can get underground ones that dump the water well away from the house.

Outside the ground must slope away from the house. Flowerbeds can be altered easily by mixing in some new soil and sloping it away from the house. I find landscaping fabric under mulch helps good flowerbeds drain proerly, although in a poorly sloped bed it makes things worse. If you have any paved areas like a driveway it should be checked with a spirit level. I don't know how to cheaply fix one that slopes towards the house, but if it does something should be done about it.


Re: rock foundation basement

Post by hb »

Ok, here we go...............

Some old houses were built on top of a spring (or next to it) cause A.) they didn't have refrigerators so if there was a pool of 50 degree water handy, they cold keep stuff longer before it spooiled and B.)who wants to go out in the cold and break through the ice in the dead of winter just to get a bucket of water.

If your house is not one of these, then you have a few choices as mentioned above. What Bry said is dead on as far as the drainage around the house is concerned. In the event that your driveway does drain towards the house you'll need to cut an opening into the driveway completely across it to create a drain to catch the water moving down the drive towards your house and divert it to a safe drainage area.

If you have a dirt floor in your basement, you need to change that. You could simply lay down heavy plastic sheeting and then cover it with a bit of gravel for a nice appearance(and to hold down the plastic sheeting) OR you could have a concrete slab installed. (this would be my choice) This should help keep out some of the moisture.

I have to disagree with Bry about not running the dehumidifier though - while I understand that by making the air dryer in the basement, it encourages the passage of more moisture through the wall- I would be more concerned that the high moisture content of the air in the basement would rot the wooden structural members of the house faster than the moisture would harm a rock foundation. BUT I COULD BE WRONG ABOUT THAT, this is just my opinion on the matter.

Finally tell us more about your house. Flooring materials in the basement, equipment housed down there, slope of your property around the house, depth of your well if it's an old one, location of your septic tank with regard to your house etc.

Then we'll be able to give you more and better answers.

good Luck.

Don M

Re: rock foundation basement

Post by Don M »

My stone basement is quite dry and my dehumidifier keeps condensation on appliances to a minimum in the summer. Perhaps you have a high water table where your house is located. If so hire an engineer to inspect your home to see what is recommended. The suggestions in the other posts are also excellent. Good Luck, Don



Post by S »

Regarding not running the dehumidifier. That seems to defy physics. If drying the upper surface causes the stone to wick more water through, that simply means that NOT running the dehumidifier allows the stones and other materials in the room to stay nearly saturated all the time, with only natural evaporation removing any moisture from the room. How is slow migration with materials nearly saturated better than slow migration with the surface, air and non-grounded materials dry? Pumping water out of a well does not make the well fill up faster.


Re: rock foundation basement

Post by Scott »

HB, thanks for the post regarding the use of springs in old foundations, I had thought that it was a possible explaination for the water running through my rock wall foundation.

Yes, we have running water coming through it when it rains, and we had/still have terrible mold issues that we are battling.

Short story long:

Our stone 18th century home in SE PA is built into a hill and the "deepest" part of the first floor (now a half-bath, luandry room)is below grade with a frame wall sytem built about 12" from the foundation wall. Well, first I thought the moisture was because the dryer vent line had disconnected from the outside discharge pipe, because my wife said she smelled something upstairs when she ran the dryer. Some lame brain PO used vinyl hose behind the walls, which did not last, but now it is hard piped aluminum.

Any how, the real cause of our mold was found during that fix. The "mortar", (actually clay with maybe 1% lime) from our walls was falling (being pushed by rodents?) against the sheetrock and it was being kept moist by something...

Well, I dug out the 2' high piles of fallen clay and became skilled at repointing from the inside with help/advice of Andy DeGruchy and his St. Astier Natural Hydraulic Lime. While I was doing this, we had some rain, and low and behold there was a 3-5 gallon per minute stream running though our foundation!

That explained the sump pump some one had installed and the french drain I found around the permieter of the bathroom foor cement pad. Problem was the dirt had ruined the pump switch. I replaced that pump with a 12-volt bilge pump (marine battery with a minder-charger) that senses water by some magic circutry and that seems to work fairly well so far. It does get clogged occasionaly, but we shake it and it works again.

Anyhow, we have to run our dehumidifier to keep the mold at bay. I hope that I can reduce the moisture on finishing the repointing after I deal with the kitchen floor sagging due to the rotten sil and floor joist, again, due to dirt contacting the joists...

So our friend with the smelly basement could have it worse...and I think that dehumidifiers are fine to keep moisture at bay when its the last resort.


Re: rock foundation basement

Post by ladybug »

Hey Don, My stone basement is dry except for the one wall that is under ground level. It stays damp. I believe your idea of the water table is my problem. What do you think an engineer would advise? My basement is finished and is our family room. The problem is that the dehumidifier is very loud. Does anyone know of a quiet one. Thanks

Don M

Re: rock foundation basement

Post by Don M »

Hi Ladybug, An engineer might try to determine if the moisture is a high water table or if it is related to drainage toward your foundation. Once that is determined he/she might suggest a French drain system to divert water away from the foundation. If it is a high water table then perhaps a sump pump might help if it is a significant problem. I would be very careful about any suggestions that require excavating the foundation to seal it from moisture penetration. That could disturb the rocks and create even bigger problems. I have a dehumidifier in the basement and in our tack room in the barn. They work well but both are fairly loud! Good Luck, Don

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Re: rock foundation basement

Post by Mrtnt »

I know this is an old thread, but I am battling a very similar and struggle to find any viable option. We have a 1900s home with a mix of poured foundation and exposed rock in the basement. I have installed a whole house dehumidifier and laid heavy plastic on the exposed rock and still we get an incredibly musty smell that permeates the entire house, but is worst in room above the exposed rock. I have filled the largest cracks with spray foam, but have yet to treat the rocks with KILZ (or similar primer/sealer) since I worry it will just flake and be a mess. I laid foil down in several areas to see if it was air condensation or seeping from the floor, and unfortunately it is the latter. I installed gutters and extended drain-spouts. I have not regraded the landscaping, but it doesn't appear to slop toward the house.

Because of the exposed boulders, it seems a B-dry or french drain would be very limited (and expensive). We DO NOT have a sump pump and I am wondering if it would be a worthwhile investment to try in the lowest part of the basement given that we have a proper basement slab? I am hoping that I do not have to dig up all my landscaping and rubber-wall the entire perimeter, but I am running out of options (and my wife is running out of patience with us both smelling like mildew constantly). HELP, PLEASE!

Thanks for any words of wisdom

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