There's one more factor that will determine the success of your finished job: the quality and the type of the wall or floor surface you'll be tiling over.
It should always be kept in mind that no two surfaces are the same. Each type of surface has its own characteristics (such as rate of expansion and contraction, moisture absorption, 'dimensional stability,' and so on), so it pays to know the nature of each surface. These characteristics must be considered when choosing the right adhesive for the job as well. The staff at your local Beaumont Tiles are more than happy to help you out here.
Regardless of type, all surfaces must be clean, dry, and free from all contamination's and existing surface coatings like polished, lacquers, sealers, or paints.
Below we list the most common types of wall and floor surfaces you may have or come across and offer important information and helpful tips for tiling over those surfaces.
For best results, the concrete must be allowed to cure for a minimum 28 days before it is tiled over. Steel trowelled concrete must be mechanically roughened (and then thoroughly washed) prior to tiling, or there will not be enough adhesion.
For concrete with hairline cracks, apply ABA Ceramic Tile Underlay prior to tiling. Alternatively you can use Barrierflex, Abaflex, or Isoflex.
All concrete release agents and curing compounds must be removed by mechanical means. For cracks larger than 1.5mm consult your local suppliers.
Due to the expansion and contraction of the timber, it is never recommended to adhere ceramic tiles directly onto timber floor. Untreated floors should be primed with ABA Multiprime. Apply ABA Ceramic Tile Underlay at 6mm minimum bed thickness. Allow to dry prior to tiling, or use the Isoflex system.
Plasterboard is a very common indoor wall surface, but is not suitable for tiling without waterproofing.
Tiling over plasterboard involves adhering tiles to a paper surface, and although this will present little problem in dry areas, if the wallboard is subjected to moisture, it may deteriorate causing failure. Plasterboard should be waterproofed with Barrierflex or ABA Superflex before tiling.
Brickwork should be rendered prior to tiling.
If it is being used as a countertop, adhesive can be applied directly onto the surface of particle board; but if it is being used for flooring, it should be prepared in the same manner as a timber floor.
As long as they are sound, clean, dry, and free from all contamination; existing tiles are suitable to tile over. If the existing tiles are glazed, roughen the surface by mechanical means.
Cement render is typically made from a 3:1 or 4:1 sand and cement mix, and may be very porous. Because of the high sand content, there may be a layer of sand on the surface that needs to be removed before tiling.
Set Plaster, or Gypsum, is a highly absorbent surface and must be primed (cement based adhesives must also be avoided). If the set plaster is over brickwork, it should be replaced with a more suitable material before tiling.
Fibre cement sheets are flat sheets of reinforced cement, and should be fixed according to the Fibre Cement manufacturer's instructions. Ensure that the surface is clean and dry.
Prime the sheets with ABA Multiprime prior to tiling. Apply Barrierflex with reinforcement mat over the joints between the sheets.
This includes Hardiflex, Versilux, Villaboard, and CSR Board. All are suitable for indoor use, but only Hardiflex is suitable for outdoor use. The manufacturer's recommendations should be followed in all cases.
Most of these sheets have a surface layer of dust which should be removed by using a damp sponge or cloth (the manufacturer may also recommend using ABA Multiprime).
There is no adhesive that will bond to fibreglass to our complete satisfaction. Check with the adhesive manufacturer if you are in doubt.
Remove any flaking paint and roughen the surface or oil based paints by mechanical means. Water-based or PVA paints aren't suitable for tiling and should be removed before tiling.
These surfaces should be rendered. Allow at least 7 days for render to cure.
One important note when considering surfaces is that two dissimilar surfaces should not be bridged with ceramic tiles.