Any idea how water is getting on the floor?

Question

I have a storage building that is regular wood construction with vinyl siding and a peaked metal roof. It sits directly on concrete blocks and has a plywood floor. The floor is about 10 inches from the dirt beneath the building, and as far as I can tell, the wood does not touch the soil anywhere (it might somewhere; hard to see the whole underside)

Yet there's always a wet spot on the plywood, not adjacent to the wall, when it rains and even for a while afterwards. The roof is not leaking, at least water is not coming through the ceiling or down the wall - and the soil under the building is bone dry!

Any idea how the floor is probably getting wet? Can water "wick" along the 2x4's to the lowest point of the floor? (the floor is uneven and this is the lowest point) And, any idea how to find out and fix this problem? I want to carpet and furnish in there, but until this problem is solved I'm stuck.

Thanks for any ideas.

Answer 1

A) The wooden support UNDER the floor may be wicking moisture up into the flooring.

B) Lack of other ventilation may be allowing the natural moisture in the air to cool and settle there. Do you have any vents along the roof line? In a house, they are at the top of the ridge (under that metal cap) and under the eves/overhang (called the soffit). If the shed is tightly closed, nothing will evaporate.

Answer 2

Get a flashlight the next time it starts to rain. You should be able to trace the leak by following the moisture trail. sitting or running moisture will shine a little bit when hit by the flashlight. Wood will darken when it gets wet. It's not coming from the underside, and creeping upward. It is coming from the outside wall or the roof. Water can easily follow a stud down a wall, but you can narrow it down by where the water starts to become. Seal the leak with caulk or repair before laying carpet.

Answer 3

OK, You say your building is on concrete blocks with a plywood floor, YET still gets water at the lowest spot. I see the water simply following the edge of your building and running down the lowest point. I would push a couple more of the cinder blocks up under your floor (on the ground) and shim them between the building and the floor until the center of your floor is a wee bit higher than the outside. In otherwords so that the floor slopes to the outside (just a tiny bit). Then, I would flash and seal the bottom edge of your building.

Answer 4

As mentioned before, put a pan over the spot to see if water is coming from above. It may be coming through a light fitting on the ceiling, and dripping off that, so the ceiling looks dry

Also wind may blow water through the cracks between the wall and roof, or around windows/doors

Answer 5

it does happen that the water run-off will "wick" up the roof and run inside between the metal overlaps and you cannot even see where this happens --- only the water will drip onto the floor and it fools you into thinking that the source is from under the floor -- look at the roof and maybe even put a bucket or pan on top of the ""wet spot"" and catch the drip .. if that doesn't work then you must cut the floor and see what's up or down as in your case................ good hunting for leaks or drips .............

Answer 6

I would check the ridge for light coming through. A little bit of rain being blown in can look like a ton of water. A drip at a time can fill a five gallon bucket. you might enter the building when it is raining, using a flash light look for wet (shiny) spots.

Answer 7

Your house's foundation is not good thus there is water on your flour