Renovate tiling without removing it Finishing-Decoration Solutions
Batirama.com 06/02/20130In renovation, the laying of tiling and solid parquet remains a market for professionals. The application of a waxed concrete look coating requires specific technical knowledge.
In the last half of 2012, improvement-maintenance work helped to limit the overall decline in activity in the building sector. A good surprise, according to professional organizations.
Less fluctuating than the new build market, the renovation market offers great prospects for professionals. Driven by the improvement in the energy performance of the habitat, it is also maintained thanks to the interior design and decoration works.
Tile remains the preferred surface in France and is still nibbling away at market share, reaching 30% in 2011 (versus 28.7% in 2010). But textile, plastic and laminate floors are becoming more and more popular. This craze is explained by their moderate cost to purchase and by implementation systems so simplified that they allow individuals to carry out the installation themselves.
On the other hand, tiling and solid parquet require the use of professionals, because the implementation of these products cannot be improvised, at the risk of seeing significant pathologies form (cracking of the tiling, lifting of the blades Of wood…).
The existing acoustic comfort. The laying of these coatings must comply with precise rules and requires the use of implementation products that are compatible with each other and adapted to the support as well as to the chosen coating.
As for waxed concrete, estimated at less than 1% market share, this is a specialist business and a market on which you should not enter without being very well trained in the application techniques recommended by the manufacturers.
And whatever new coating is used, the latest version (n°4) of CPT 3529 relating to P3 floors under renovation stipulates that the installation of a new coating must not deteriorate the existing acoustic comfort. in neighboring premises. So keep in mind that after the works, the acoustic performance must imperatively be at least equal to that observed before the works.
A provision especially valid in the case of renovation work in collective housing.
EXPERT OPINION
Jacques Manevy, tiler in Saint Etienne
“Beware of the extra thickness”
This artisan tiler does 70% of his business in the renovation market. “I decided to stay in my core business as a tiler even though I specialized in laying terracotta. Most of the time, I renovate without removing the existing floor tiles. In this case, you really have to pay attention to the extra thickness that is created, especially at the level of interior doors and window doors.
Vigilance is also required in fitted kitchens because it is necessary to ensure that you have sufficient reservations to be able to remove household appliances placed on the floor if necessary, such as dishwashers for example.
If this is not the case, it is better to warn your client that the work plan will have to be raised. The most common requests relate to the installation of new tiles. People take the opportunity to change format, I recently installed 3 x 1 meter.
I also sometimes get asked for solid parquet floors in renovation. In this case, I systematically refer my clients to a fellow carpenter. And as for waxed concrete, I refuse because I'm not trained. It's too risky if you don't master the specific implementation techniques. »
Solution 1: Laying a tile covering on a tile
The prior study of the tiled support and its preparation are two essential steps that should not be neglected. The choice of a suitable adhesive mortar makes it possible to avoid the risks of cracking and/or shrinkage.
Tiling is a material that requires a prior study of the existing support. Visually, identify any repaired parts, sagging or shearing, cracks, broken or sunken tiles, etc.
The sound test by probing with a metal ruler makes it possible to determine if tiles are blown. In this case, they must be counted with the defects identified during the visual examination. If the surface with defects represents more than 10% of the total surface, the entire tiled surface must be removed.
Otherwise, remove only the tiles that have defects and fill them. If the tiling to be covered has a flatness defect of more than 5 mm under the 2 meter rule, leveling must be carried out.
In the case of a healthy and flat surface, unglazed and unpolished tiles must be washed with a soda solution and rinsed with water. Once the substrate is completely dry, the glued installation of the new tiling can be done without prior application of a primer according to CPT 3529 Floor P3 renovation.
However, many professionals systematically apply a primer. Note that the existing floor can also be blasted and then swept. The implementation is then done by single or double gluing depending on the format of the tiles and the adhesive mortar according to the recommendations of the CPT.
The latest generations of improved deformable adhesive mortar allow simple gluing even for formats up to 3,600cm2 and limit the risk of shrinkage and cracking. It is also possible to use an uncoupling mat to prevent the risk of cracking and detachment.
Solution 2: Glued laying of parquet on a tile covering
There are no specific rules for gluing solid parquet on tiles because NF-DTU 51.2 only concerns work in new buildings. In renovation, the use of a primer and/or a leveling compound or only a specific adhesive is possible.
First precaution, remember to store the parquet in the room to be renovated at least 15 days before its implementation so that it adapts to the ambient temperature and control its humidity before installation. The lack of flatness of the supports allowing to receive a glued parquet must not be greater than 1 mm of maximum deflection under the rule of 20 cm and 5 mm of maximum deflection under a rule of 2 meters.
On existing tiles, it is recommended to lightly sand and scratch the surface in order to eliminate residues of cleaning products. Then you have to suck up all the dust. Thus, it is possible not to apply a primer beforehand.
If necessary, use an acoustic insulation layer to limit the sound of the glued parquet. The implementation of the floor can then be affected in two ways. Single-component flexible spreadable adhesives are applied with a notched trowel, evenly distributed over the entire surface of the carefully prepared support.
For its part, bead gluing allows the parquet to be glued to very slightly irregular surfaces. The parquet is glued directly to the support by beads of glue applied perpendicular to the direction of the boards.
Solution 3: Waxed concrete look coating on a tile
Very trendy in renovation, polished concrete-look flooring is a niche market, rather high-end. But be careful, it must imperatively be carried out by professionals trained specifically in these self-leveling or spatulable multilayer systems.
As with tiling and parquet, renovating an existing tiled floor with a waxed concrete-look coating requires good preparation. The manufacturers recommend sanding the tiles with a grinding machine to roughen them. The ideal is to arrive at the level of the joint to obtain the smoothest and most adherent surface possible.
Then apply a pre-coat with an epoxy resin charged with silica in order to cover the tiles with a uniform, homogeneous and flat surface whose appearance will resemble coarse-grained sandpaper. This sandblasted epoxy treatment cannot be separated from the support and provides a very good grip profile.
It is also possible to pass the tiles directly with a coarse abrasive before dusting them carefully and applying an epoxy primer. Once the substrate is clean and prepared, follow the manufacturer's recommendations to the letter. There are two common systems.
The first is a 6 to 10 mm self-leveling colored leveling compound, the second is a spreadable millimeter product (1.5 to 2 mm). Depending on the desired finish, they may require the application of around ten coats, including several of protective varnish. The implementation of these multi-layered systems requires solid training and a lot of practice.
Serious manufacturers on the market only sell their solutions to professionals whom they have previously trained and supported in test sites before integrating them into their networks of approved applicators.
Source: batirama.com / C. Jappé
