Primer for Tiling onto 12mm Plywood

Bal APD primer used undiluted is perfect for ply, make sure your ply is screwed ( not nailed ) every 200mm. Then use a bal single part flexible adhesive for fixing or a flexible Ardex adhesive both are very excellent adhesives. When grouting make sure which ever grout you choose is also flexible, I always use Ardex grout it gives the best finish. Follow this and you can't go wrong, hope it helps.

APB Primer can be used but to be honest I don't use Marine ply anymore to strengthen the floor and give support to tiles ( Old School very Old School ) I only use Hardie Backer or Kerikol adhesive or plastic ply never use Ply wood Can't see by it used it for years total game changer I use only Plastic Ply from Nicobond no gimmicks there is a science behind this stuff... Marine Ply It's the way we all did it in the past and yes most still do and yes with screws (But please please if using this method only use screws that will only penetrate the both the ply and only half way through the existing wooden floor. Also if securing the original floor to the joists use a Pipe, Wire, Stud detector the trick with all of these detectors is to practise on a known material, and adjust the sensitivity of the instrument so that it gives an accurate reading. So if you want to locate copper pipes below 20mm timber floorboards, use a piece of scrap copper pipe and hold it under a piece of timber, and adjust the dial on the detector so that it beeps only when it is definitely over the pipe. Alternatively, find an area in the house where a length of copper pipe is above floor level (eg below a washbasin, or entering a radiator), cover it with a notebook or folded newspaper 20mm thick, and again adjust the detector dial until it gives a reliable reading. You are then set to survey your bathroom floor for the pipes. Remember, however, that even when properly adjusted, pipe and cable detectors (even the expensive ones) will usually beep in response to all metal objects, so they will pick up the nails or screws used to fix the floorboards, and possibly also the electrical cables for the lighting in the room below. Accurate tracing of your pipes, therefore, will require a bit of detective work, as well as the use of the detector. And before you attempt to lift the flooring, push a thin blunt plastic blade through the gap between two boards and run it along until you hit the joists - these will usually be 400mm (16in) apart - and if you prise the board up over a joist, you stand less chance of damaging a pipe or cable. The best method to make sure you don't damage a water pipe or any other type of pipe or wire is to make an opening and use you camera on your phone to look under the floor to check for pipes and other types of pipes or wires. (FIND AVIOD THEN SCREW ) Other problems using Ply is trying to remove the ply in the future if you have issues or want to replace the tiles oh and some use very thin ply thinking that is enough and only nail it down wow always ask the tiler what he intends using as a substrate. Plywood was used for over boarding floorboards before laying or fixing ceramic tiles. However, this caused problems because if the grouting cracked or the sealant failed water would creep in and rot the plywood. There could also be the problem of fungal growth which often reacted with the adhesive causing the tiles to become loose. The ‘Pro’s’ amongst us thought that the problem could be overcome by using ‘Marine; grade plywood but the preservatives in this material migrated through the grout causing an orange stain to develop. A minimum of 15mm plywood if it has to be used for over boarding floorboards and this creates another problem... a potentially dangerous step up into the tiled room. The only answer and I have tried a few is to use Nicobond N5100500 Plastic Ply is an award-winning and time saving product which allows you to fix tiles and natural stone to timber floors, without the worry of them cracking in the future. Also as I stated before Hardie backer or Kerikol adhesive but not on painted or varnished surfaces. The two part system helps to prevent problems of damaged floor tiles by reducing the effects of timber shrinkage, warping and rotting. The need to install thick sheets of marine grade plywood or similar over-boarding with a minimum 15mm thickness is eliminated. Benefits: Self adhesive Manufactured using 50% recycled plastic ingredients Ultra thin 2mm thick - no more steps/reducing door heights Reduces stress on tiled floors Moisture proof Easy to handle Heat resistance - suitable for undertile heating Easy to cut - scissor, no need for exposed blades Easy to install - requires no skilled labour Impact resistant Cost effective No drilling Ready to tile immediately - no curing/drying times Speedy installation Each pack contains 4 x 600 x 500mm sheets = 1.2m² Simple installation: 1. Ensure the existing timber floor or chipboard is securely fixed 2. Apply a priming coat of Universal Bonding Agent & Sealer (PVA) to the floor 3. Easy to cut and install, lay the Plastic Ply sheets in a staggered/brick-bond pattern 4. Cover with a layer of Flexible Tile Adhesive (*Recommended use of C2 S1 Category Adhesives) prior to laying tiles or overlaying with the Nicobond Wet Room Tanking Sheet for a watertight wet room floor, as part of Wet Room Tanking System Remove the ply get shot of it don't use it if you want your tiles to last a life time especially porcelain tiles. Also for Hardie backer see their website