DIY Doctor UK DIY Forums

In my old property the floors were concrete so I tiled on top of it but in this property there are wooden floorboards.

I want to take up the old carpet and lay tiles or laminate flooring.
What preparation do I need to do before laying the new floor?

Hi if your laying laminate flooring then you will need to used a laminate flooring underlay. These a few different types of laminate underlay to choose from, this would be up to you to choose depending on your budget. Also you will need to choose a laminate flooring suitable for use on bathrooms where floors might get wet. Also keep in mind your bathroom door, you may need to adjust the length to fit over any new floor surface.

If your tiling the floor prep wise you will need to lay sheets of plywood to cover the floor boards to give you a flat surface to tile on. The boards you lay should run horizontally to the floor boards, so across the boards rather than following the same line. Screw this down with counter sunk screws. Take care not to hit any pipes or cables when screwing down. In both case its good to check you have an even, sound surface to lay your new flooring onto. IE: check for loose, squeaky floorboards before you lay your new floor and make good. Ues a water proof grout with tiles....hope this helps? let me know how you get on mate. :D

Thanks for the reply.

So if I lay laminate flooring I only need an underlay but if I lay tiles I need to use plywood first.

Thanks for the tips.

Hi....yes mate. I would only lay a thin ply sheets to lay tiles on. This gives you a flatter surface which results in a better job. Dont suppose it would hurt laying ply, then underlay then laminate but cant think a reason why you would need to do this though unless you had a poor floorboard surface? If its your first time with laminate or floor tiles my biggest tip is take your time and think about how you will lay the flooring out first, even draw a plan on some paper. Its easy to jump straight in then realise you have made a big mistake towards the end. Trust me its easy to do. Good luck.

If you are talking about laying ceramic or quarry tiles the ply needs to be at least 12mm thick but preferably 18mm. Floors move a lot, nathroom floors move more than others because of high humidty. The slightest movement in the floor, even 1mm will cause tiles to move and they are not flexible so the joint, or possibly the tile itself will crack. See our project on laying floor tiles where there is more information./

"I would only lay a thin ply sheets to lay tiles on. This gives you a flatter surface which results in a better job."

As Doc has indicated anything less than 12mm WPB ply (and I'd use a decoupling membrane on top of that as well) screwed at 200mm centres will result in cracked tiles in the future.

I can't see how a thinner sheet gives you a better surface unless you mean a thin sheet gives a better surface than the plain floorbaords in which case you are correct.

Cheers

Hi there, just been reading through all your comments and i've got a couple of quieries myself:

If your laying ply at 12-18mm, then your adhesive + tile at a thickness upto 10mm. The total thickness would be 30-35mm (not icluding any membrane), my question is: What happens near the door edge? i.e. the new layed floor would be higher than the door frame base, along with the facet that the door would have to be shaved down to fit. If the door was one of those hollow jobs then you only have so much to play with...and if there was a carpet joining up to this new floor, say the bathroom floor, wouldn't there be a step? How would you get round this as i'm currently about to do a floors in both kitchen and bathroom.

Also, there is a step down from the kitchen. The edge of the step is rounded, again with the kind of thickness mentioned above, how would i cover up the edge of the tile and make good the edge underneath the tile?

thanks