So why should we consider using these decoupling matting solutions on our new floors before tiling? Well it is very common to be spending a small fortune on a natural stone or tile floor and the last thing we want is a giant crack appear through the middle of it a few months (sometimes a year) down the road once the screed starts to move and shift causing a hair line crack in the screed. This crack will transfer through the screed and up into the tiles above causing your new stone/tile floor to adopt the same crack! AAAARRRHHGHG.... click to our portfolio of stones
The insurance policy that will give you total piece of mind is a decoupling membrane. Otherwise known by their brand names as Ditra Mat or Bal Rapid Mat. Here is a brief look at their sales pitch...
BAL Rapid-Mat uncoupling matting is designed for use on floors with limited movement and floor coverings, such as tiles, that require zero movement and prevents reflective cracking caused by lateral movement, shrinkage cracks and board joints. It can be used for installing ceramic, porcelain and natural stone tiles, and concrete pavers.
Timber and heated screeds can also cause movement and lateral stresses that can result in tiles cracking or de bonding. Uncoupling the floor and tile covering, by installing a separating material like BAL Rapid-Mat between the two surfaces, allows the floor to move independently and isolates the floor covering from the shrinkage and stresses in the floor.
DITRA Matting is a polyethylene membrane with an anchoring fleece laminated to its underside. The matting has a grid structure of square cavities which are each cut back in a dovetail configuration. DITRA Matting is specifically designed for tile and natural stone installations.
Cost of the two options?
It is a good idea to shop around online to get a good price for the two mats as various companies do offer discounts quantity purchasing. The Ditra Mat tends to come in at around between £7 and £10 per square meter inclusive of vat. The Bal Rapid between £8 and £12 per square meter, so not much difference. You will also require a flexible tile adhesive to stick it down with. Speak with your tiler for advice on this.
How much should i buy?
Well you will need to buy enough to cover your entire floor and adhesive to stick it down with too, so it can be an expensive part of the project you hadnt budgeted for, but it is a very worth while investment to make to ensure that your stone floor looks great for years to come, without a big fat crack running through it...
There will be an extra cost for installation from your tiler too. Your tiling contractor should have experience in laying a decoupling matting as it is very common and will probably be to advise you on purchasing and ordering the correct adhesive etc. Top Tip: Check with your screeding company as to the type of screed you have laid and ask if it requires any special primer application prior to laying matting down to it?