Laying Cork Floor Tiles

Design Aspects

When designing the floor covering one shall establish which class of agglomerated cork floor covering is suitable for the intended intensity of use. For suitability see European Standards: EN 685 Resilient floor coverings - Classification

Potential Installation Problems

The most common problems and source of dissatisfaction are not caused by the product itself but by inappropriate installation procedures (deficient sub-floor preparation, use of wrong adhesives or finishes, etc). Installing cork floors in areas with excessive sub-floor moisture should be avoided. When using levelling compounds the complete drying of compound is essential for good adhesion. It is, therefore, important to follow the manufacturer’s instructions. Only recommended adhesives and finishes should be used.

Conditioning

Packaged tiles, adhesive and varnishes should be acclimatised on-site for at least 24 hours before installation. Remove the tiles from packaging just before spreading the adhesive.

Sub-floor

Preparation of the sub-floor is essential for a successful installation. Concrete floors must be quite smooth, levelled, permanently dry and free of dust and grease. On non-floating sub-floors and on sub-floors that are not sufficiently ventilated, adequate installation should first be applied. The percentage of moisture in the sub-floor must not exceed 3%. Irregularities in the sub-floor must not be filled with glue but should be smoothed with adequate filler. Wooden floors should be made smooth (it may be necessary to machine sand the floor). Linoleum or vinyl must be removed, or if not possible, must be made quite rough to ensure adhesive bond.

Under-floor Heating

If under-floor heating has been installed in the sub-floor, the following basic rules apply:

• Turn off the heating 48 hours before installation starts.
• Turn on the heating in steps not earlier than 72 hours after installation.
• Do not exceed a temperature of 26 °C measured at the surface of the floor covering. Higher temperatures are not only discomforting to feet but may affect the bond of the adhesive.

It must be taken into account that some expansion and contraction of the cork floor will occur. This is a natural consequence of changes in interior temperature and the structure’s moisture content.

Planning the layout

Start in the middle of the room by stretching an adjusting string. For this purpose measure the middle of the wall and the opposing wall. Start along the string and determine the way and the pattern by laying some loose tiles. The layout of the installation should be determined by the installer (who may consult the end-user if appropriate). The following principles should be followed:

• Minimise the number of joints,
• Lay strips along passages in the direction of traffic, along the length of the room, or towards the wall containing the main window.
• Avoid the use of sensitive patterns where there is a risk of fading from high temperatures or intense sunlight.
• Ensure that, as far as possible, material from the same batch is used in the same area.
• Position tiles to avoid forming joints witching 4cm of the skirting.

Gluing

The recommended adhesive for installing cork tiles is contact cement (solvent or water-based). Apply adhesive to perimeter of the room using a paintbrush. Using a low nap roller or a proper trowel apply the adhesive to the sub-floor. Apply adhesive with the roller to the backing of the cork tiles. Any adhesive stains should be removed immediately.

Laying

When the adhesive is dry (normally it turns clear and is tacky to the touch, roughly 15 to 20 minutes depending on humidity), place the first tile and press it against the floor with the help of a rubber hammer. Once the first cork tile is in place, align the next tile to the edges of the first and press it tightly against the edges of the first. Special attention should be paid to the alignment of each tile, particularly around the edges and corners.

The floor must be rolled in both directions with a 50Kg roller every 30 minutes, to ensure that the tiles are firmly bedded into the adhesive.

Light pedestrian traffic may normally be allowed after 1 day.

Finishing

We recommend that cork tiles should be varnished after installation (sealing of joints and improving wear resistance). Always varnish with a specially recommended cork varnish. It is essential to follow the varnishing of your supplier strictly.

After the laying is complete, wait at least 24 hours in order to let the adhesive coat drying completely (depending on the type of adhesive, temperature and relative humidity of the air). Clean the floor thoroughly, vacuum it and remove any adhesive stains, if necessary by sanding slightly. Apply 3 coats of varnish (when varnishing pre-varnished cork tiles, 1-2 coats is enough). It is recommended to sand slightly between the varnish coats with fine sandpaper (grain 240), and then vacuum.

Light traffic is normally allowed after 1 day, but final hardening of the finish is achieved after 1 week. Wait 2 weeks before using the recommended maintenance products.

Note: Always apply adhesives and varnishes at temperatures between 15 and 25 °C and keep them from freezing.

Maintenance

The cork floor must be kept clean with a damp cloth or by vacuuming. Intensive use requires occasional special maintenance. Mats in entrances should be used, but never with latex or rubber backing because these can mark the floor.

All varnished floors require refurbishment depending on the intensity of use. When refurbishing, sand the old varnish carefully and remove wax, maintenance products, dirt, etc. Remove the dust by vacuuming and apply 2 coats of varnish.

Attention

Cork floorings are high quality, natural materials and should be handled accordingly. Despite all due care when manufacturing the cork tiles, there is always the possibility of variations in structure and shade. Before you start laying the tiles, distribute the tiles in such a way that variations are not striking.

Cork (as wood) may change colour when exposed to sunlight over long periods of time. Cork fading is subtle and does not change the beauty of this material under normal wear and proper maintenance.