Raising a garage floor

[andywatson]

Hi, and thanks in advance for any help.

I am about to convert my garage into a bedroom. The garage has a concrete floor, as does the rest of the house. Obviously I want to raise the floor of the new bedroom to match the rest of the house. The garage floor is 155mm below that of the connecting hallway.

My plan is to sit joists on a dpm (probably unecessary, but better safe than sorry) on the garage floor, then cover them with plywood. The joists will be at 400mm centres with kingspan in between. So far, so good (unless I am completely on the wrong track).

Here's the problem:

I can buy 125*47mm joists. I put 18mm boards on top, and I am 12mm too low. Whats the best way to raise the level by 12mm? I don't want to hang the joists because the span is over 4500mm, and I would need bigger joists.

Any ideas?

Cheers

Andy

 

[alfiembra]

Go to a timber merchants and get them cut from a deeper section to the exact depth you need.

Might be missing a trick here but I would have thought you need to create an airspace below the floor to aid air circulation and prevent damp. build a single brick sleeper wall down the centre of the garage with a wallplate on top splitting the span in two and use shallower joists might get away with 4x2's and easier to level the floor up.

HTH

Alan

 

[noseall]

d.p.m.

60mm kingspan floor insulation.

95mm screed.

job done in a matter of hours.