Flooring Question

I am about to lay 600x600 porcelain tiles on to 12mm ply which is over boarding 18mm floorboards is there a certain way of laying ply eg opposite way to floorboards and is it advisable to glue & scre

7 Answers

Best Answer

opposing direction to floor board screws roughly 200 x 200 squares then pva over this .This process will stop to much movement and reduce the likelyhood of cracked tiles good luck

Answered 14th Apr 2012

DAW contracts

Member since 11 Apr 2012

Just screw the ply every 200mm in every direction then pva it before tiling.
Temple carpentrys advise is utter rubbish and is a typical example of people on this site giving opinions on matters they know nothing about.He should stick to what he knows which is certainly not tiling.

Answered 13th Apr 2012

m w building construction and property maintenance

Member since 28 Sep 2008

Are you sure you have to use ply? Minimum thickness would be 15mm and whilst ply is used a lot,it is not the best material for what you are doing.Go into your tile shop and ask about hardie board and other alternatives.It will save you some height on the final finish floor too.

Answered 14th Apr 2012

Roc builders

Member since 25 Aug 2011

Best practice is to use a tile backer board rather than ply. It's a cement based sheet that can be cut easily.

Answered 14th Apr 2012

jd kent

Member since 14 Jun 2008

Use exterior grade ply or backer boards both as good as each other. backer boards are handy if you can't raise the floor to much. I screw every 150mm in grid pattern using a level to mark the lines in pencil at looks a lot neater and helps to get the screws uniform.
Just one tip don't use pva to seal the floor before tiling use a good acrylic primer and make sure you use a good quality flexible adhesive and grout that is compatible with porcelain as some aren't.
Hope this helps

Answered 16th Apr 2012

Ch kitchens bedrooms bathroom

Member since 4 Jun 2011

I am with the real tilers on this one, screw the board down every six inches in a grid type fashion, ensuring that all screw heads are sunk. Then prime with an Acrylic primer for example BAL APD diluted with water at 5:1 (off the top of my head) then ensure you use a flexible adhesive suitable for porcelain.

Answered 31st May 2012

CamLen Bathrooms

Member since 31 May 2012


It is common practice to lay the ply in an opposing direction to the floor covering underneath. It usually lends extra strength to the existing floor if done in this way. I couldnt advise as to whether you need to use both screws and glue together, it depends on the floor underneath. If you glue, you can be sure there will be little, if any, movement. Screws could be used initially to keep the boards in place whilst the glue cures, but you would only need a few in each board i think.

Anyway, Good luck.

Temple Carpentry

Answered 13th Apr 2012

Temple Carpentry

Member since 11 Apr 2012

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