Special Subfloors: part 3

GOOD PREPARATION IS OVER HALF THE WORK

SUBFLOOR IN CONCRETE AND A SAND-CEMENT COVERING FLOOR

There are special requirements for subfloors when fitting parquet. Professionals are well aware of that. Certainly when it comes to fitting solid parquet or parquet with a special pattern such as herringbone or Hungarian point, it is essential that anything out of sight (i.e. including a subfloor) is of the right quality. If you don’t pay enough attention to that, you could get problems later.

In this article we consider specifically how to tackle various things when confronted with ‘stony’ subfloors, in particular concrete and the highly fashionable sand-cement.

Concrete If you opt for a concrete floor, first of all you have to decide how to apply it to the sand (or check how it already is applied). And so, this means that a damp screen has to be fitted onto the sand first of all and that you fit a damp screen to the walls with an upright edge. It is important to apply a layer of foam on top with upright edges. Indeed, the idea is that both layers protect the floor from rising damp and from damp which can come onto the floor via the walls.

You then apply the layer of concrete to the layer of foam, with a sand-cement covering floor. You can see the upright edge of foam and the upright edges of the damp screen from inside out (even after the sand-cement covering floor is applied). If your floor doesn’t have a damp screen or layer of foam, you don’t fit solid parquet. You can fit industrial parquet because you can fit a damp screen yourself.

Sand-cement covering floors You have two options with a sand-cement covering floor on a concrete structure. This concrete structure is either solid or it contains channels. If it is a solid structure, it comprises pre-stressed concrete beams. This solid structure is used the most in modern new buildings.

With the other structure you are confronted with floorboards with channels, something used mostly for upstairs floors. The sandcement covering floor lies on the top, but you have to take care during the construction process. You must ensure that no rain water seeps through the openings at the sides of the open boards. If damp gets into the channels, there will be a risk of damp problems later.

You can easily check for damp problems from the ceiling. If you notice any streaks there, that is a clear warning sign. Moreover, although this might be much less of a problem with solid concrete floors, it is still best to take care here.

With a sand-cement covering floor on a solid concrete floor, you often find nowadays the covering floor applied directly to concrete, with a damp screen and sound insulation board on the concrete. Remember here that the concrete must have the necessary time to dry out properly. Furthermore, don’t forget that the thickness of a sandcement covering floor at ground level is no more than 50 to 65mm and 50mm for floors upstairs. Some things are due to the fact that various pipes have to be fitted into the floor and sound insulation requirements are becoming increasingly strict.

One specialist

Design Parquet

You choice your underlayers according to the use. There are 3 objectives : to sound insulation, to reduce the resonance noise or to create a barrier against moisture backing. Design Parquet offers different underlayers according to your needs. The most popular Design Parquet underlayers for their convenience are : - L’iso dB, patented system, is a ecological system (without CO2 emanation), providing both fixing the parquet floor with sound insulation (18dB). This underlays allows fast implementation thanks to 2 adhesives faces. Glue isn’t necessary.

L’iso alu, meanwhile, is a waterproofing underlayer, a real barrier against moisture. We warranty until 10% of humidity in the support. It’s easy to install with the adhesive face. The wood floor is glued on this underlayer with NAVYCOL PS glue.