Hi, Looking to tile 600 x 300mm porcelain Tiles onto a kitchen stud wall with Plasterboard skimmed and painted with white emulsion. Only the kitchen so doesn't need compate waterproofing. Area to tile is approx 6m2. 1. Do I need to use primer? From research online, it seems I do. It also seems to say use acrylic based but the one attached seems to be OK but is water based? Maybe I am overthinking this? My assumption is that using a primer wouldn't cause any harm so may as well go ahead and do it. Is that correct? 2. Adhesive. I have in mind to use the below Mapei Ultimate Showerproof ready mix as it has good reviews and looks easy enough but happy to mix powdered if better. For this ready mix, do i need the primer, or can it go straight on to the wall? I want to get it right first time so any help is much appreciated. https://www.screwfix.com/p/mapei-bu...7Ma4orwc2Z8D4X5hl5AaAnpLEALw_wcB&gclsrc=aw.ds
Not recommended to tile over painted surfaces and simply applying a primer coat is insufficient Sand down emulsion with course paper - P40/P60 to roughen up surface and break through paint layer, getting back to the plaster skim Score the plaster with criss cross lines over complete area using a scraper corner or Stanley knife Again, course sand over to remove small bits of paint and plaster that are hanging loose Brush down or hoover wall Prime wall, either specific tile primer or simply diluted SBR @1-4 water That adhesive in link is totally unsuitable to your job ! It’s not for porcelain tiles and not for tiles of your size - max 300x300 - it’s all there in the product spec to read You need a bagged powdered adhesive, cement based suitable for porcelain tiles Porcelain tiles are hard to cut, assuming you will have some cuts to make, again, planning the layout and having the correct tools / tile cutter is essential Good luck
As @DIYDave. says - get the paint off the wall or you will end up with a pile of tiles on your worktops! In te past I have used a power sander with metal plate to take the paint off and also ideal to break through the surface of the polished skim. Next time, just platerboard - no skim is ideal for tiling. A good quality adhesive such as Ardex X7
Thanks for the reply. Looks like some extra preparation work to be done. That's fine. At least I know beforehand. You saved me from a potential disaster! So, I need a set of primer/ SBR/ tile adhesive and grout. The two options below seem logical. Both suitable for plaster/ plasterboard and porcelain. I preferred the idea of ready mixed adhesive but ok, powdered is the way to go. I also like the idea of slower drying adhesive. The rapid/ quick set options terrify me - I'd like to take my time, and make adjustments along the way. Worth mentioning that the tiles are a very light stone colour, so white adhesive ais the best option from what I can see. Mapei Plaster Primer & Super Flexible adhesive https://www.toolstation.com/mapei-plaster-primer/p57804 https://www.diy.com/departments/mapei-super-flexible-white-tile-adhesive-20kg/38145_BQ.prd https://www.screwfix.com/p/mapei-ultracolor-plus-wall-floor-grout-white-5kg/71681 NX (Norcross) Multi Purpose Primer & Standard Setting Tile Adhesive https://www.wickes.co.uk/Norcros-Multi-Purpose-Primer-1LT/p/167675 https://www.wickes.co.uk/Norcros-Standard-Setting-Tile-Adhesive-White-20kg/p/169651# https://www.screwfix.com/p/mapei-ultracolor-plus-wall-floor-grout-white-5kg/71681 Any thoughts on the pros and cons of these products, or specific recommendations? I'd prefer to order from one of the larger diy suppliers if possible.
Thanks. I'm not familiar with Ardex and this isn't sold in one of the main diy stores. Is there a big difference in the quality to the above, and which is easiest for a beginner to work with?
Ardex is considered to be one of the best tile adhesive manufacturers with a very varied range. Not normally a DIY shed product but decent tile stores will stock it. Depending on where you are there is a dealer locator on their website. You will have no problems using X7, you can mix a little or a lot, it is forgiving if made slightly too wet/dry and has a good life after mixing. X7 https://ardex.co.uk/product/ardex-x-7/ and aavilable in White (or grey). Then, depending on tile spacing uses on of their Grouts - available in around 30 colours giving you the option to match time colour, have a contrast or plain white. Then, for sealing you can also get matching silicon.
Irrespective of adhesive quality, the maximum weight on a skimmed wall is 20kg per sq . In my experience porcelain tiles can easily exceed that, depending how thick. That’s also assuming it’s 12.5mm board, battened at 400mm centres