Frequently Asked Questions

Natural stone can often display crystallised deposits of salts on the surface when outside in the elements (called Efflorescence). This can be minimised by waterproofing the stone, as well as using a penetrating sealer such as ‘Dry Treat Stain Proof’.

Stone products are frequently used in external and swimming pool areas, providing a natural element to your landscaping. It is possible for some corrosion to occur from pool chemicals though, whether it is a chlorinated or salt water pool. However, with the non-slip finish that is usually used on external paving, there should not normally be an effect.

2cm slabs can be used in external areas however we recommend 3cm with a view to improving longevity and minimizing risk of cracking as a result of structural movement and/or thermal loss and gain.

Our recommendation for joint width is 2mm minimum internally and 3 to 4mm externally, (joint width is important as it helps accommodate structural movement). If possible allow a perimeter expansion joint to help minimize any damage to flooring from building movement. In the case of single items that are wall to wall items such as step treads or cappings the suggested joint width should also be allowed between wall and stone.

Option One, Impregnating Sealers:
For this option we recommend “Dry Treat Stainproof” which has a 15 year guarantee. Note that impregnating sealers make the surface more resilient and less porous and as a result easier to clean and maintain. They do not protect the actual surface in any way, that is for example, the surface would still be vulnerable to acidic attack from spillage of alcohol or citrus juice.¬†‚”Dry Treat Stainproof” is a once only application and is guaranteed for 15 years if applied by a certified applicator.

Option Two, Surface Sealer:
For this option we recommend Belinzoni RR1, a wax based product that provides an easy to maintain surface and protects the stone from corrosion or attack that might result from any kind of spillage. This finish is maintained simply by addition of a dash of RR1 to the washing water each time the floor is washed!  The initial full application would be repeated on a 1 to 3 year basis depending on the extent of the traffic.

Some stone tiles are produced with a fibreglass and epoxy mesh backing. Davco have tested some of these products and established that “Davco two part rapid” is effective in installing such tiles. Note that installers must be warned to check tiles as installing to ensure that none of the epoxy/fibreglass backing is loose in which case any loose parts must be removed. As external areas are subject to weather and thermal loss and gain a further precaution can be taken by removing 50% of the backing on each tile with a grinder to improve adhesion.