Dirt floor in shed

wiboy · Sep 5, 2011

I have a 12 by 20 lean-to style shed fully insulated with a sliding door on one end set on class 5 lime rock. The windows have a lot of condensation on them humidity is high in the shed. The question is if I put plastic down and then 4 inches of concrete would that fix the condensation problem or do I need to put a fan in to exchange the air? Thanks for any help or ideas.

David G · Sep 5, 2011

Ptrobably both, but the concrete will help. You should think about insulating under the concrete if you are in the appropriate climate.

I see no condensation on my windows, but run a dehumidifier in the summer anyway.

thurlow · Sep 5, 2011

Might depend on where you are; around 'here', adequate (non-powered) ventilation takes care of any moisture problems. I wouldn't pour concrete inside a building without a vapor barrier underneath.

KJM · Sep 5, 2011

Ventilation, Ventilation, Ventilation, Plastic under concrete is a wast of money. The only good plastic can do is if you have water coming up under the floor. Foil backed bubble insulation and good air flow work fine.

evilboweivel · Sep 5, 2011

at least one inch foam insulation board under the concrete

Brian G. NY · Sep 5, 2011

Plastic under concrete is a waste of money?

That foil backed bubble insulation in it self is a vapor barrier!

Unless. maybe, you live in Arizona, you are going to get moisture from the ground.

Concrete, by itself, will not totally eliminate the problem. With proper vapor barrier in the floor and walls and some ventilation, your shed will no longer rain inside.

David G · Sep 5, 2011

I have double bubble and tubes. I would do double bubble with foam next time.

Russ from MN · Sep 5, 2011

I am a firm believer in poly under concrete, you can do a condensation test and prove that it works.

2510Paul · Sep 5, 2011

By all means put a good thick vapor barrier under the concrete. I did in my shed and my humidifier easily handles any moisture. I did not in my house and in the summer that humidified cannot keep up. What is in the walls also matters but when it comes to the floor it is pretty clear to me. Paul

Spook · Sep 5, 2011

I put a vapor barrier under 4 in of concrete for my barn floor, now the place is bone dry. I have another structure with no vapor barrier, and everything in there rusts up. This is in Michigan and we have humidity.

Anonymous-0 · Sep 5, 2011

6 mil poly, 1 1/2 styroroam, 10 mil rebar 1 foot squares placed on rebar chairs, then your concrete.... Lyle

Anonymous-0 · Sep 6, 2011

Plastic under concrete works. My first house up the road never had plastic and the lfoor was damp on humid days.

My new house 100 yards away had 2 layers of plastic and it is dry as a bone.

36 Coupe · Sep 9, 2011

Put plastic under the concrete floor of my shop in 1968.It works plus it helps the concrete cure.Concrete has to give up moisture slowly to have maximum strength.Thats a problem with forums.Some one will post some thing that is dead wrong and people will believe it.One fellow was ready to put diesel fuel in the crankcase of his tractor and run it for a while to clean it out.

retired farmer · Sep 9, 2011

You have never heard of putting fuel in the crankcase? I"ve done it. You just don"t leave it in there and run it too long, maybe five or ten minutes at most. Don"t hurt anything. Drain it out and change the filter and put in new oil.

Dirt floor in shed

wiboy

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David G

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thurlow

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KJM

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evilboweivel

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Brian G. NY

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David G

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Russ from MN

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2510Paul

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Spook

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Anonymous-0

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Anonymous-0

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36 Coupe

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retired farmer

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