Best way to do floor of garage/games room

[jetsetwilly58]

Hi

I have decided to turn my garage into a pool/games room.

The garage is part on an extension that was built 20 years ago. However, the garage was built over the old driveway and no floor was put in (it is still the tarmac driveway.

I am not planning to make this habitable, so not concerned with building regs etc, just want to make the room damproof etc.

So, how to do the floor. I want to pave it with reclaimed stone. I need to level it as there is a slight slope (from the days when the camber of the drive).

Do I put sand down, then DPM or the other way round?

Also, planning to put the paving stones onto this directly, or would I need to screed first?

I am looking to do this cheaply but want it to be damp proof.

Advice please

 

[Himaginn]

I wouldn't put a DPM straight onto tarmac. It's too rough and will probably pierce the DPM.

How much height do you have to play with. You'd need something like 70mm minimum for a screed and I'm not sure you could put a screed on tarmac. You'd need something like 50mm sand blinding on top of tarmac for DPM anyway.

 

[jetsetwilly58]

Thanks. I am aiming to do the job myself and not sure I would fancy screeding. If I put sand first (to level the slope), then DPM, would heavy paving stones sit on that?

 

[Himaginn]

You'll have difficulty getting them level and even because it will depend on the sand under the DPM.
So you'd either need another layer of sand, with the edges somehow preventing movement of the paving stones.
Or you could use a weak mortar on top of the DPM.
It's the way I lay slabs but I put the mortar bed on top of the weed barrier.

The biggest problem you're going to have doing it like this is avoiding damaging the DPM, walking and moving the slabs.
Normally it would be protected by concrete or screed.

This is an excellent guide:
http://www.pavingexpert.com/layflag1.htm