Workshop floor

[grumpy brit]

Hi, I have a wooden garage, 42mm T&G walls, but unfortunately I built it on an existing slab. The slab, it appears was not laid well and I think its letting damp through. The floor was painted in, some kind of floor paint, which is now lifting. I have used a damp meter(?) and I am getting high readings where the pant has lifted.
I would like to do something about this to lower the humidity, which at the moment is running between 51% and the highest was 71%, over a month approximately.
So..
1. paint on liquid vapour barrier. Would mean taking up the rest of the floor paint, then repainting. Don't think that would work.
2. Pour in self levelling flooring, on top of a vapour barrier. Would probably bring the floor height up to much
3. Jigsaw type floor tiles on top of vapour barrier, recommended by a Architect friend.

Has any one else had similar issues and fixed it, or any one got any tips on a product. I am leaning towards the floor tiles, they can be sourced specifically for garages.

Thanks in advance

Colin

 

[Jameshow]

I'd probably use a damp proof membrane followed by a foam or rubber floor overing depending on the weight of the objects on the flooring.

 

[Katomi woodsmith]

For me the water enters one corner and exits on another, I have put polly down then boards that on battens 1 inch thick
Once a month in the winter or heavy rain I lift the boards and polly to dry out the floor
No need for test meter for me, I can see the water flowing lol

 

[HamsterJam]

I laid a damp-proof membrane followed by a frame of 2x2 treated timber. Filled the gaps with 50mm insulation board then covered with 18mm flooring grade chipboard sheets screwed down to the frame. No more damp floor and much warmer, although it does reduce useable height by approx 70mm. I guess you could use thinner frame and insulation if height is an issue.

 

[Doug B]

My first choice would be the two part epoxy floor coating I’ve used this before very successfully but as you say the existing paint would need removing.

The liquid membrane with self levelling on top will work but self levelling isn’t recommended as a finished surface so would still need covering with a finished surface.

I’ve seen jigsaw type floor tiles at a mates workshop, his are incredibly robust & hard wearing but cost him a lot of money, so I guess it would be down to your budget.