Convert existing room to a garage

[RogerD]

This is reverse of what most people want.
The house has a large ground floor room, which was a shop, which would be more useful as a garage. It has a wooden floor, lathe & plaster ceiling with bedrooms above. It could be separated from the adjoining downstairs room by inserting a concrete block wall.
What do I line the ceiling with now asbestos is banned ?
I assume I need to replace the timber floor with a concrete floor 100mm lower.
What do I need to do to meet building regs ? RogerD

[Bob Plum]

The ceiling is simple - two layers of standard plasterboard with no joins coinciding in the two layers - it's usual to offset the second layer by half a board in both directions.

I don't beleive building reg's would be involved but 100mm of concrete of the correct grade is the minimum for light use.

[DevilDamo]

If it's reverting back to a garage, then you just need to make sure you will maintain the fire resistance through the internal walls and ceiling. As for the floor, you will need to check that the floor adjacent to the new garage is also timber with vents, which would need to be maintained under your new floor, so look at utilising a beam and block floor?

Will there be a door between this new garage and the existing room(s), because if so, then you will need to provide a difference of level of min. 100mm between the rooms or look at sloping the new garage floor away from the building to the external area.

There could be a little more work than originally expected.