Floor sanding company ZexWoodFlooring gives advice on floor sanding

In our (Zexwoodflooring) experience, it’s not as difficult to lay parquet as it is to sand it and then varnish it. Parquet can be re-sanded and varnished several times, as the grain of the wood allows it, but it is better to have a craftsman do the job. Simple wooden plank floors are easy to sand yourself. Just don’t overdo it by scraping off too much wood.

You will need special floor sanding machines for this job. If you decide to do the work yourself, you can rent tools. Information on the sequence of the work and how to use the tools will be provided. The putty is applied according to the shade of the wood, which will make it possible to hide unevenness almost imperceptibly.

It is pressed as deeply as possible into the irregularities and, when dry, is scrubbed with a sanding cloth. Sanding is carried out by changing fabrics from coarse to fine. This depends on the wood. It also makes the surface very smooth, leaves no streaks and improves the adhesion of the varnish layers. The varnish is applied crosswise or wet-on-wet.

The main ways to protect the surface of wooden floors:

Varnishing – for all floors, oiling – for hardwood and hardwood floors, waxing – for any wooden surface, even stairs. Shrinkage – for softwood floors. The durability of the floor will depend on the method of coating and maintenance chosen. Old painted floors are checked for protruding nail heads.

Selecting the sandpaper

(a) for a new surface: initial sanding – paper grit N 36-40 medium sanding – paper grit N 60-80 polishing – grit N 100-120 (b) for a varnished surface: initial sanding – grit N 24-36 medium sanding – grit N 60-80 polishing – grit N 100-120 (c) for a painted surface: initial sanding – grain size N 16, the following procedure in ‘a’ is used.

Attaching the sandpaper to the drum of the sanding machine. The normal dimensions of the drum are: 200 mm x 675 mm. The paper is clamped on the grinding drum by axes with one side flat (milled). The clamping is done with special keys, which are supplied in the rental kit. Note the notch in the clamping drum; it has a slight angle of inclination.

It is therefore necessary to maintain the same angle of inclination when cutting the paper! Align the drum axles so that the slit is as large as possible (by circling the axles you will see a milled edge). Make strips of sandpaper scraps 25 mm x 180 mm in various thicknesses. Cut the sandpaper to the required length; the ends of the sandpaper must fit into the clamping slot and end behind the centres of the clamping axes. The paper must not be too long and must not go into the bottom of the drum cut-out! Cover the drum with sandpaper so that there is no gap between the rubber and the sandpaper. Slide a few of the strips you have made together into the joint (the higher the grain size of the paper, the more strips and vice versa). N 16-24 strips are not required.

Place the keys on the ends of the clamping axes and tighten the paper by turning both keys simultaneously. If the axes slip and fail to engage the paper, increase the number of strips. After clamping, check that the paper fits evenly everywhere and that there is no slack. If looseness is felt, determine the cause of the looseness and repeat the paper loading sequence!

Working with a drum sander.

Slowly push the machine forward and at the same time lower the sanding drum using the lever. It is very important to raise the drum while the machine is still in motion before stopping or changing the direction of the sanding!

This way you will not leave pits and impressions on the surface to be sanded. Reverse grinding starts in the same way as forward grinding, by lowering the grinding drum and moving. Push the machine at a steady speed to avoid uneven sanding. After the forward and reverse stroke, the machine is repositioned 15-18 cm to the side.

Initial sanding (diagram l): Paper grain N 16,24,36,40. Sanding at an angle of 20-45 degrees in the direction of the grain. Important!!! When sanding with N 16 paper, turn the sandpaper after 10 to 15 minutes of work. Medium sanding (Diagram 2): Paper grain N 60,80 Sand in the direction of the grain. At the same time the smoothing is carried out. Polishing (Diagram 2): Paper grain N 100;120. The sanding shall be carried out in the direction of the grain of the wood.

Working with an edge sander.

The paper used is the same grit as for the drum machine. This machine is used for edges and areas that cannot be reached by the drum machine. The sanding is done in a circular motion along the edges.

To avoid burrs, keep moving all the time. Working with a disc polisher (diagram 3). For a better result, carry out additional polishing with a disc machine. Two-grain sanding discs are normally used. Primary grinding is done at N 60-80. Secondary (final) grinding is N 100-120. Grinding in two directions according to the example.

Removal of cracks and fissures. Some cracks and fissures appear only after the floor has been sanded. Therefore, check them before the final sanding stage. Use a putty, selecting it according to the type of wood. Use a metal trowel to apply the putty. Varnishing the floor. Before varnishing, vacuum the floor, window sills, radiators, etc. thoroughly with a vacuum cleaner. The room to be varnished must be free from draughts; this is particularly important for fast-drying varnishes.

Start painting in a light part of the room and work your way towards the shade so that you can spot defects and correct them in time. For more precise information on quantity, application method and drying, please refer to the varnish supplier’s instructions.

Intermediate sanding (during varnishing)

This sanding is preferable after the first coat has been stripped. Sanding is carried out with a disc polisher or simply by hand using a wooden pad. Sanding with N 120 grit paper. Do not apply high pressure, move quickly.

IMPORTANT!!! The air permeability of the dust collection bag is very important for the perfect operation of the machine. Do not rinse and shake the dust bag in time when it contains no more than 1/3 of the bag volume. After each machine shutdown and at the end of operation, be sure to shake out the dust bag and dispose of the dust in a suitable waste container. Keep the container outdoors to avoid fire!


Varnish is a pigment-free stain that enhances the texture of the wood. It is both an insulating material and a primer in itself, although it is advisable to dilute the varnish with approximately 10% white spirit or (for acrylic varnishes) the same amount of water when applying the first coat.

When the first coat is dry, rub it lightly with the finest abrasive cloth, vacuum it, and wipe it off with white spirit, then apply the second, base coat. Once dry, polish again to ensure a good, reliable application of the third layer and a strong surface in the future.

The varnish should only be applied with a good quality, split-fibre brush. A mohair roller or a cost-effective and efficient pad may be used. Avoid causing dust by all means, as the particles will settle on the surface and become uneven. This is particularly important when applying the last coat.

Leave a Reply

Your email address will not be published. Required fields are marked *