Garage Floor Sealing

[deadfire19]

I'm looking to set up a small workshop/gym in my garage. The garage is part of a 1930s house and has a concrete floor.

There doesn't seem to be a DPC (or perhaps it's been broken) between the concrete and the dirt since the concrete is constantly slightly damp in some areas (towards the center, not the walls). The rest of the ground floor is suspended on joists.

Ideally I'd like to seal the floor in some way to get rid of the concrete dust / dirt and dampness. I've heard tanking could be an option, or an epoxy resin floor, but I'm slightly worried about trapping all the moisture in the floor.

Im resistant to suspending it on joists since the height is only 2.4m currently.

Any recommendations on how to deal with this?

 

[Why Not Indeed]

The "correct" thing to do would be to dig it out and do it properly, and then you could also increase the headroom as well.
You may be able to paint it with a liquid epoxy DPM, but how are the edges where the floor meets the wall? Are they decoupled from the concrete floor or are you just going to end up increasing the amount of moisture going in to the walls from the slab?

You could "simulate" a sealed floor by laying a sheet of DPM across the floor for a few weeks and see what happens at the edges.

 

[Tigercubrider]

My attached Garage is dry apart from a small amount of water on very wet days seeping under the door.
all it has is Garage Floor Paint. I continued the paint up a couple of bricks as skirting.
Another mate’s garage is detatched and we painted a liquid dpm, followed by a membrane that went up the walls.
We than added a chipboard floor and carpet.

If a workshop/gym you will need ( probably) a rubber mat system to stop impact damage and insulate your feet in cold weather.

 

[foxhole]

Concrete, absorbs and releases moisture on a daily basis, if you just want it dust free brush over with weak pva mix.
Gym and workshop require different flooring what’s your priority ?