Basement dirt floor question

[Aaron_W]

Ok, so not a garage, but a basement / cellar question. I don't have a garage, and the space under the house doesn't cleanly fit into either definition for a basement or cellar. I apologize up front for these deficiencies in my character.


Anyway, on to my question. The major portion of the usable space has had a concrete floor poured, while the rest is dirt. There is one portion that for some reason was walled off into a sort of utility corridor and left unfinished with a dirt floor. This provides access to the phone connections, main electrical panel and heater. When we moved in the water heater was also located in this space, but we replaced it with an exterior wall mount tankless unit years ago.

During heavy rain the floor become damp and because it is cool, it stays damp for long periods. No standing water, and not mud, just damp earth. I have placed a fan in the area to increase air circulation which seems to help dry the floor somewhat.

This space is poorly utilized so I'm placing some shelves along one wall for camping gear. It is well away from the heater and electrical panel which are good 15-20 feet down and around a corner. This area just provides access to that space. The shelves still leave a comfortable walking space, probably 30-36" wide.


So if you've made it this far, now my question:

I was thinking about putting down a layer of gravel (maybe an inch or so) to level the floor and cover the often damp earth. Just wondering if there are issues to doing this that may not be obvious.
Being the lowest point this is the only area that seem to receive this dampness.

 

[73fxe]

I don't see any problems with gravel, but how about 8 mil. plastic under the gravel or bagged concrete to make a solid floor?

 

[Lelandwelds]

Well, it is a floor that you can weld on without damage. You could film creepy horror movies down there. There aren't any shallow six foot long depressions in rows, are there? Talk about a great Halloween backdrop!

 

[HandsomeDan]

I don't see any problems with gravel, but how about 8 mil. plastic under the gravel or bagged concrete to make a solid floor?

How about all three?

 

[Aaron_W]

I wasn't sure if laying down plastic would be a good idea or not as it would trap the moisture in the ground. Putting down a concrete floor is definitely an option, but my concrete skills are not very strong. The part that has a concrete floor isn't that great either though so at least the prior owner set the bar low for me.

Well, it is a floor that you can weld on without damage. You could film creepy horror movies down there. There aren't any shallow six foot long depressions in rows, are there? Talk about a great Halloween backdrop!

Oddly enough we found several very long dead, semi-mummified cats under the house when we first moved in. Very creepy things to run into when crawling under the house replacing plumbing.

 

[matt_i]

Imo you want to trap the moisture in the ground! I'd go 10 mil as you don't want to puncture it. Tape all seams.

 

[tomroblee]

I don't know how the radon levels are in your area, but having a dirt floor certainly won't keep the levels down.

 

[cybrdyke]

concrete skills ****? Try patio pavers.
CD

 

[MikeF2316]

I think you want to leave the moisture in the dirt. I'd put down plastic, sand and concrete. If you're not, then I'd put a dehumidifier in that area before storing anything there. The dehumidifier may be a good idea regardless.

 

[Lelandwelds]

Every inch of my place is solid rock before you hit two feet deep. My septic tank hole is about nine feet of solid rock. My well had a stretch of about 150 ft of uninterrupted solid rock. ( It looked like a cement kiln when they drilled it.)

I have trouble imagining owning a basement. Even with the kitty cat graveyard, I am a bit jealous.

The problem with plastic is when wet the ground moves under it when stepped on. After a wet/dry cycle or two, you have a bunch of ankle breakers instead of smooth, fairly level dirt. I have never done this but how about shoveling 8 inches of dirt onto the concrete, lay plastic on level ground, replace dirt, and lay another layer of plastic. Or, plastic then plastic catwalk grating? Plastic then pressure treated deck?

I may not be as envious now that I think about it.

 

[James-W]

Have you spoken with a concrete person to see if the floor could be poured and if it can, what are are we talking about for a cost? If possible I tend to think having a concrete floor would be about the most nicest way of doing it.

 

[Aaron_W]

This is mostly due to my starting to organize the basement. I'm still bouncing ideas around in my head.

The air moisture isn't bad overall, the prior owners used the house as an office and they stored paper files in cardboard boxes the area of the basement with a concrete floor. The moist dirt mostly just creates a bit of a musty smell that I though gravel might help reduce. It isn't soggy, just damp most of the winter.

I haven't seriously considered pouring concrete, not a bad idea but a very low priority. I have bags of sand and gravel left over from some fence posts and thought it might be a cheap and fairly easy start to eventually extending the concrete floor.

I had not considered plastic, not sure if it is better to let the moisture into the sand and gravel to disperse slowly, or to trap it below a layer of plastic.

The pavers are an interesting idea.

Every inch of my place is solid rock before you hit two feet deep. My septic tank hole is about nine feet of solid rock. My well had a stretch of about 150 ft of uninterrupted solid rock. ( It looked like a cement kiln when they drilled it.)

I have trouble imagining owning a basement. Even with the kitty cat graveyard, I am a bit jealous.

The problem with plastic is when wet the ground moves under it when stepped on. After a wet/dry cycle or two, you have a bunch of ankle breakers instead of smooth, fairly level dirt. I have never done this but how about shoveling 8 inches of dirt onto the concrete, lay plastic on level ground, replace dirt, and lay another layer of plastic. Or, plastic then plastic catwalk grating? Plastic then pressure treated deck?

I may not be as envious now that I think about it.

It is mostly above ground, the floor is maybe 1 foot below ground if that. We sit on a gentle slope, so on the street corner side there only a crawl space of 1-3 feet. Around the mid point there is a sort of retaining wall where the ground was dug out which provides more head room to around 6 1/2 to 7 foot at the far corner by the basement door. This nicely places the joists and pipes right at smack me in the head height for most of the usable space.

It is actually a better working space than it sounds. Standing is fine, just have to remember to duck when I walk. I've tied warning flagging to the most painful offenders to remind me.

 

[cybrdyke]

I have about 600 sq ft of dirt/mud floor in an old barn that I've been trying to figure out how to finish. The barn is useless with a mud floor. Everything rots. It's not accessible enough to have concrete poured and it's too big for me to do concrete by myself.
So, I've been looking at alternatives. I want a solid floor, not gravel. There's lots of critters, so I'm not real interested in a raised wooden deck.
That's why I suggested pavers. I can do it myself at my own pace. And I can get them from craigslist cheap from time to time.
I started looking at a YouTube video of something called "DirtGlue". Unless the video was a total scam, it looked like a very promising product for what I need. It sounds like it might work for you, too. I reached out to them for more info. We'll see what they say. Has anyone ever heard of DirtGlue?
CD

 

[ynned]

I have about 600 sq ft of dirt/mud floor in an old barn that I've been trying to figure out how to finish. The barn is useless with a mud floor. Everything rots. It's not accessible enough to have concrete poured and it's too big for me to do concrete by myself.
So, I've been looking at alternatives. I want a solid floor, not gravel. There's lots of critters, so I'm not real interested in a raised wooden deck.
That's why I suggested pavers. I can do it myself at my own pace. And I can get them from craigslist cheap from time to time.
I started looking at a YouTube video of something called "DirtGlue". Unless the video was a total scam, it looked like a very promising product for what I need. It sounds like it might work for you, too. I reached out to them for more info. We'll see what they say. Has anyone ever heard of DirtGlue?
CD

Never heard of Dirt Glue, but it sounds expensive. When I worked as a highway contractor, we had pretty good luck different times with soil cement on problem wet areas. A specialty (usually) sub had a machine (think giant rototiller) which tilled the sub grade down to about eight inches or so, while simultaneously injecting powdered cement from a bulk truck. The resulting combination was re - graded and rolled. After a day or so it was set enough to support the entire paving train. I can't remember what kind of ratio they used for the amount of cement, but there is plenty of info online. It may be possible for your barn to do on a small scale with a garden tiller and sacks of cement. Maybe sprinkle down a couple bags, till it in, rake it around for grade, then tamp with a hand tamp. Probably couldn't hurt anything, at least. It'll be a ton of heavy hand work, though.

 

[NUTTSGT]

Our basement (cellar) was pretty much a dirt floor when we bought the house. The sump pump pit was nothing more than a mud hole with a pump sitting in it. I started digging it out, it was slow and hard work I can now stand under the floor joists with out bending over and the wife will go into the basement.

I came to the conclusion years ago, it's never going to be anything more than a cellar and a place for the utilities. It was damp down there and we had a dehumidifier until it died, which did help. Now, I just have a box fan running 24/7.

When I dug it out, I put stone down along with some corrugated tile leading to the sump pump pit. I poured 3 1/2" of concrete which I figured was plenty for what it was for. I hauled all the dirt out in 5 gallon buckets and the stone and concrete went down the same way. Like I said, hard work but it has been worth it.

While I considered plastic, I felt it wouldn't work for what I was doing, a section at a time. If I would have done the entire floor at once, yeah I would have done a vapor barrier. Even without the plastic, it's night and day difference.

 

[DOUGD]

Crusher Run with lots of "Fines" makes a great floor in these situations ,if a concrete floor is not required. It's cheap and easy to work with just fill to the desired height rake it level and with a little moisture it will be very firm and solid especially if you have existing walls to form it. I did this in an old horse barn tack room that originally had a wood floor that was termite infested on top and rodent infested below. Filled the room with Crusher run about 10 inches deep, raked it smooth and hosed it down. Very solid and level and no where for the rodents to live below the floor.

 

[Skiff Builder]

Never heard of Dirt Glue, but it sounds expensive. When I worked as a highway contractor, we had pretty good luck different times with soil cement on problem wet areas. A specialty (usually) sub had a machine (think giant rototiller) which tilled the sub grade down to about eight inches or so, while simultaneously injecting powdered cement from a bulk truck. The resulting combination was re - graded and rolled. After a day or so it was set enough to support the entire paving train. I can't remember what kind of ratio they used for the amount of cement, but there is plenty of info online. It may be possible for your barn to do on a small scale with a garden tiller and sacks of cement. Maybe sprinkle down a couple bags, till it in, rake it around for grade, then tamp with a hand tamp. Probably couldn't hurt anything, at least. It'll be a ton of heavy hand work, though.

I did soil/cement as a test of a potential floor in my shop. Took a 4x8 area and dumped 1 90lb bag portland cement. Raked it in about 3.5 " deep while sprinkling with water. Screeded and hand tamped, covered w/plastic to cure. Ultimately built a wood /aggregate base floor, so did not go with soil/cement. I tried to break up the test area about a month later. I gave up because it was so solid- floored right over it.
Skiff

 

[E.E.]

I had a similar situation in my house when I moved in. One portion of the basement, a separate room really, had a dirt floor. The rest of the basement was poured concrete. House was built in 1947. I believe the room was used as a root cellar for storing food and hanging deer, etc. At any rate there were the dampness issues the OP described. I put down a layer of gravel, then a layer of thick plastic, then concrete. I don't remember now if mixed it myself or had a truck come in, but I seem to recall mixing it myself--it was 25 years ago so not that fresh in my memory. I had a friend at that time who was a pretty accomplished mason and we did it together. It made a huge difference in the overall air quality in the house. That room is now tight and dry.

 

[Aaron_W]

Thanks, the area of real concern is only about 10 feet long and 3 feet wide. The whole area I'm looking at is 15-20 feet long and maybe 5 feet wide.

I suspect being the lowest point it just collects moisture from the area around it and the small amount that comes under the door in heavy rains also pools there.

I'm going to mix a couple bags of sand into the dirt and then put a layer of gravel over the top. If nothing else it will provide a base if I later pour concrete.

Thanks for the comments, it helps to bounce ideas around.

 

[Aaron_W]

I don't know how the radon levels are in your area, but having a dirt floor certainly won't keep the levels down.

I had to look that up, I've heard of Radon, but it has never been brought up as an issue. My county, and in fact the whole northwest corner of California (where I am) is rated low potential.

 

[Jlbc212]

You could do concrete one small area, like 3ft x 3ft, with one day's pour and so on. A small area pour is easy to form and level up.

 

[NUTTSGT]

Thanks, the area of real concern is only about 10 feet long and 3 feet wide. The whole area I'm looking at is 15-20 feet long and maybe 5 feet wide.

I suspect being the lowest point it just collects moisture from the area around it and the small amount that comes under the door in heavy rains also pools there.

I'm going to mix a couple bags of sand into the dirt and then put a layer of gravel over the top. If nothing else it will provide a base if I later pour concrete.

Thanks for the comments, it helps to bounce ideas around.

When it comes time to pour the concrete, I have found this site very helpful and a quick reference.

https://www.concretenetwork.com/concrete/howmuch/calculator.htm#calculatorPage

 

[jetnow1]

I would not worry too much about trapping the moisture, I do not think the rest of the floor has a vapor barrier. The small area you are looking to finish would not really change
that either way, but it would make a big difference in the moisture levels in your basement
area.

 

[bczygan]

Radon is specific to a particular location.

Everyone should have it checked.

Bill