Show Your Grit When It Comes To The Rub
SURFACE preparation before installing planks and applying a finish is often overlooked. If the floor isn’t fully ready when the seal is applied, it will not take properly and will be ineffective. It may also impede the overall life of the finish.
Sanding is the best place to begin and choosing the correct sanding method is fundamental in determining subsequent appearance and quality of the surface. However, there are three exceptions to this process:
n Old floors that are completely or partially worn, greying or flaking, or that have been treated with water-based, polyurethane or other varnishes.
n Where there are deep impressions or severe mechanical damage to the wood.
Depending on what type of finish is applied, different measures need be taken.
If a finish such as Osmo’s Polyx-Oil, which does not form a thick layer on the surface, is applied, then rough and uneven areas should be removed before applying the product (eg, sanding with a single-disc machine).
The surface condition changes how the flooring should be prepared. It may be necessary to start with a rough grade of sandpaper (40 grit) or a little finer, 60-80 grit using a belt grinder.
On old or badly damaged floors, the initial sanding may need to be even rougher (24 grit). In any case, a test sanding should be done before sanding the whole area and the gradual increments recommended should be observed. Remember that the harsher the initial sanding, the longer the entire sanding process, for a smooth surface finish.
We recommend a final sanding with 120 grit, for transparent finishes, to 150 grit for opaque finishes, using a single or multi-disc buffing machine.
The floor should always be sanded in the direction of the grain of the wood – and should be moved continuously to prevent marks where the sanding machine has stopped. Edges that cannot be reached using the floor sanding machine should be sanded using a special edge sander.
Another element to note, is repairing the flooring. Where there are damage or imperfections such as cracks or holes, use of a wood filler will help cover these faults, making them barely noticeable if applied correctly.
After the product is dry, it can be sanded to create an even surface, so the finish can be applied.
Other repairs, including squeaks or loose floorboards, should also be fixed before applying the finish.
Once the floor is even, repaired and smooth, do ensure that it is clean. A wood orbitor will perform a thorough, intense clean.
To remove all dust, sweep and vacuum the floor carefully. This will allow for maximum adhesion of the finish. Once these processes are complete, you can apply your finish.
Craig Pawson is Osmo’s wood and finishes specialist
T: 01296 481220
This article has been reproduced from the Contract Flooring Journal’s website. You can find them at www.contractflooringjournal.co.uk.