Garage floor wet

[bluenun20]

I notice that my garage floor gets wet at certain times of the year, it has been dry all through winter
with all the rain we have had.
It turned less cold 2 days ago and felt milder and the floor is wet in places again.
I have a pitched tile roof and have had a look from inside and the felt is dry, no rips.
I left a bucket where a wet patch always appears and there was no water in the bucket, just underneath it.
Water does not appear to be getting under the garage door, there is a lip to stop that.

I have plastic containers around the edge of the garage floor and it stays dry underneath them, see 2nd picture.

I will try to post a couple of pictures.

Any ideas what is going on?

 

[jonsho]

Condensation perhaps? Is it well ventilated? I had water drips on the floor and it was condensation forming on the cold roof and falling down. My vents had become blocked with shed crap. Cleared up when I gave them space to breathe

 

[Harry Bloomfield]

Condensation....

The fabric and anything in the garage, have been very cold for weeks, then suddenly we get a spell of warmer weather. Moisture in the air, then suddenly condenses out of the cold surfaces, in your garage. Rather like when you walk in the house, from the cold, wearing spectacles - they instantly steam up. It will evaporate, once everything settles at the same temperature.

 

[jj4091]

I would agree the most likely cause is condensation, but would have thought you would have been able to spot it dripping from somewhere. If it is always in the same place then I would guess the DPM under the concrete was damaged during construction and the damp patches appear as the water table rises. Not much you can do about it if that is the case

 

[bluenun20]

Thanks for the replies.

My first thought was condensation, there is no ventilation in the garage as far as I can see.
But the roof felt is dry, I went up step ladders and felt it. Nothing seems to be dripping from above and
the bucket does not collect water.

The floor was wet for 2 days and nights, we had some rain last night but the floor is completely dry today.
It just seems odd that the moisture is in specific areas like the 2 circular patches in the centre of the floor.

I was also thinking a damaged DPM but I would have expected a wet floor today as it rained last night.

 

[jj4091]

Try drilling a hole a couple of inches into one of the patches then check once it dries out to see if the moisture is rising or just on the surface.

 

[jonsho]

It's chucked it down today, any worse or nah?

 

[bluenun20]

The floor was wet last Thursday and Friday but has been bone dry ever since despite all the rain we have had.

 

[Harry Bloomfield]

The floor was wet last Thursday and Friday but has been bone dry ever since despite all the rain we have had.

Obviously, condensation under the roof surface.