Creating a level floor...

[eandbee]

Hi,

I have an open plan hallway - it is partly exposed floorboards, the remainder (near the entrance) laminate flooring (laid on top of floorboards). I would like to replace the laminate with tiles.
My idea was to remove the floorboards (35mm thick), replace with 18mm plywood base and then tile on top, i.e. so that the two floor areas are level with each other.

When I started to remove the floorboards I noticed that the joists are not entirely level (it's an old house). There is a drop of about 25 mm over 3m away from the external wall.

My question is how should I create a level surface for the tiles? Build up one end / plane off the other??

(I'm a complete DIY novice).

Thanks.

 

[Johnboy54]

My suggestion would be -

You'll need to find your level with the existing floorboards that you're leaving down, using a long straight edge, spirit level and chalk lines.
You said 18mm ply, but everything I've seen says 25/30mm for tiling floors onto. Less than that allows flexing and cracked tiles.
Decide on the overall thickness of the tiles and ply and take that from your floorboard height. With your straight edge, line, whatever, now you need to measure, mark and build up or reduce the height of your joists.
Reducing them will probably leave an uneven surface, so I'd take them down slightly below the required height, then nail a length of 4 x 2 to the joist to give a level surface to screw to.
When it comes to tiling, use the search box for 'floor tiling' and you'll find loads of advice.

 

[eandbee]

Thanks for the advice! I was a little worried about using 18mm plywood but didn't really have much choice as the floorboard height is 32mm. Allowing 10mm for the tile, 4mm for heating plus mortar, I'm still slightly above the floorboard height even with 18mm. To compensate, I added quite a large number of nogs (??!?) between the joists - I bolted new 'joists' onto the existing ones to create a level base..!!

Probably not a very professional job but I'm quite proud all the same..