Grout widths will need to be at a minimum of 3mm-5mm. We can supply expansion joints colour matched to our grouts both cement-based and epoxy. The DMP under the screed will stop rising damp/water and this matting on top of the screed will protect the tiling structure from above and below.īritish standards state that expansion joints should be inserted every 8 meters of tiling length but externally we state every 3 meters and perimeter joints should also be used if the floor borders any building/wall structures. Using this matting will waterproof the structure from both positive and negative water pressure and it will also assist the tiling structure in dealing with the extremes you get in terms of expansion and contraction externally. This can be fixed with any of our S1 tile adhesives and again no priming is required. For external tiling of this type and size I recommend the use of either Dural Ci++ or Alfa Pro matting and all joints and the perimeters need to be sealed with the waterproofing tapes, which can also be applied if the screed has not yet fully cured. If the screed has not yet fully cured and there is no standing water on it, you can fix the tiles with either of our S2 tile adhesives, but you do not prime the substrate. Substrate curing before tiling can commence is approximately 6 weeks. Substrate curing before tiling can commence is approximately 3 weeks.Ĭoncrete Screeds: Prime with 2 diluted coats of ROCATEX Acrylic Primer or 1 diluted coat of ROCATEX Ultimate Grip Primer. Sand & Cement Screeds: Prime with 2 diluted coats of ROCATEX Acrylic Primer or 1 diluted coat of ROCATEX Ultimate Grip Primer. Unless stated otherwise, any reference to the term “diluted” means 1 part primer mixed with 1-part clean water. The following information provides further details for preparing various common substrates. Lay a suitable damp-proof membrane (DPM) such as black visqueen on the ground and then the relevant screed (either sand & cement or concrete) needs be applied / poured. All substrates should be prepared to provide a rigid and secure base without deflection and suitable to support the intended weight. Even though we will not guarantee the above system, using our adhesive in the fixing process over traditional sand & cement mortar, will have far better results than not using any adhesive at all.Īll surfaces must be clean, firm, dry, free from all loose matter including dust, dirt, oil, grease, laitance and any other contaminants that may affect adhesion. No special product is required when using any of our adhesives, you just need to make sure that the fixer back butters the tile with the adhesive. This is where you comb a full bed of adhesive on the floor, back butter the tile or paving and press into the adhesive, ensuring that there are no voids below the tile. The same fixing process should be adopted for external tiling as internal, where we recommend a full bed fixing method is adopted. When the winter comes the fixing mortar will be put under extreme pressure and inevitably the debonding process will begin. The other big issue here is that large blobs leave voids under tiles where water will naturally fill over time. Over time, when freeze thaw sets in in the winter, you start to see tiles debonding from the mortar and cracking. As there is no damp-proof membrane (DMP) inserted into this system you cannot protect the fixing mortar and tiles from moisture rising up from beneath. This is the traditional method that pavers used and have done so for many years but there are a number of flaws with this process especially when fitters adopt these methods with lighter tiles outdoors. In this first method, external paving is laid onto compacted crush & run aggregate and paving/tiles are laid in blobs of sand & cement motor.

The main benefit of using the adhesive, is that it is highly flexible and copes better in terms of expansion and contraction due to the extremes outside structures having to cope with. The second method, which is using our tile adhesive is a far better option than using traditional sand and cement in terms of performance. But we also have noticed that customers are less aware of the methods used to install outdoor tiles, so here we run through the two main methods. Over the last few years there has been a big increase in people using 20mm tiles for external tiling.

Laying outdoor tiles