Let's start with an example of a nice surprise that happen in life - you remove the carpet from a room in your home and discover a valuable original parquet floor is hiding beneath it! Especially when you consider that installing a brand new parquet floor may costs anything between £70.00 - £120.00 per sqm. And that’s just for a simple herringbone or basket weave pattern.
That little treasure will need a little bit of work to bring back its beauty and here is a few steps of advice how to achieve it.

Missing, Damaged or Loose Blocks

Check the floor for blocks which are no longer firmly attached to the subfloor – you either notice movement or a hollow sound comes after a ‘knock-on-wood’. Check for missing blocks – usually caused by works on central heating or other plumbing/building work.

Parquet floors produced over the last 20 years have a tongue and grooves sides used for the fitting. Handle the removing of loose/damaged blocks with care or you may loosen connecting blocks needlessly. Missing blocks can be sourced perhaps from another room, which you do not plan to restore - cupboards in or around the room. Another option are the reclamation yards. Before you set out to find replacements, check the size of the existing blocks - there were plenty different types of wood blocks in Imperial measurements around when these floors were popular (1930 – 1970). Another thing to assure for the supply is to check the timber is from the same type to prevent colour variation between the new and the old floors to happen.

Cleaning The Blocks & Subfloor

“In the old times” parquet floors were normally fixed down with Bitumen – a black tar ‘adhesive’ which is no longer allowed to be used. Any residue of bitumen and subfloor material stuck to the blocks must also be cleared.
The Bitumen will affect the bonding time of the modern adhesive you use to install the blocks back. If normally it takes between 6 – 8 hours, the bitumen may increase this to 14 or even over 24 hours!

Levelling The Subfloor

You may discover that the subfloor below the blocks removed is quite uneven. Or removing the Bitumen has damaged the concrete or sheet material. You can use acrylic leveling compound to level a concrete floor out as best as possible – 3mm maximum per coat. Always read the instructions carefully before you begin with this type of job! And even though it is non-water based, allow sufficient time for the compound to dry before you start installing the wood blocks back.

Refitting The Blocks

If there is a height differences between the blocks, especially where old meets new – the reclaimed blocks – start with G40. Recommendations come to sand with the grain, but herringbones and various other patterns could make this a bit problematic. However, the various sandings you will have to do will sort this.

Start from one wall and ‘walk’ with the belt-sander across to the opposite side; walk back sanding over the same area. After doing the last row in this direction, turn 90 degrees and redo the whole room in the same way.

Place G40 paper on the edge-sander and tackle the areas the belt-sander couldn't reach.

Repeat the area with G80. Make sure you start sanding with empty dust bag - you’ll need the dust of G80 – for mixing with the wood-filler later. The dust from the first sanding will contain dirt and residue of the old finish layer.
After finishing with process 2, vacuum-clean the whole floor.

Gap Filling

If you want to fill the gaps in your parquet flooring, mix the collected dust from the second sanding process with resin wood-filler. Don’t make too much at once, it dries rather quickly. Fill the larger gaps as best as possible – the excess filler on the wood blocks will be removed by the third sanding round. If you want you can also gap fill the whole floor with a thin layer of filler, using a flat trowel, to fill almost every tiny gap.

After all gaps are filled, leave the applied filler to dry out sufficiently - 30 to 60 minutes depending on how deep the gaps were.
Use G120 sanding paper for the third sanding round, this will remove the excess wood filler and give your wood floor the smoothest surface, ready to have new finish applied to it. Once again carefully vacuum-clean the whole floor.

Application of The Sealer

The hardwax-oil will bring up the natural beauty of the parquet floors best in a non-glossy way. The oil will penetrate the wood for long term protection and the wax will create your wear and tear layer, protecting your floor against dirt and drips.
Another option is the varnish. It comes in matt, satin or gloss finish. Significantly more durable than the hardwax-oil based products, the varnish requires less maintenance, although a polyurethane coat of polish is always recommended.
For both products, recommended from the trade comes will be Osmo, Bona and Junckers products. These products are only available in specialised wood flooring merchants and come in bottles of 5L (varnish) or 2.5L (oil) enough for one coat of 50 sqm.
Always, always read the instructions of the product you’re going to use.

The Perfect Finish

It’s here you have to decide how perfect you would like to finish your floor. And when we say perfect we really mean it. Using a G120 screen or G150 fine sanding disk, placed on a slow rotary machine over a white buffing pad and applied just before the final coat of the varnish or oil, will do desired effect.

This fine sanding will put down the “hair of grain” raised by the hardening and application of your finish and let your final coat of sealant bond perfectly to the previous coat.

Job done! Allow at least 12 hours before you put furniture back in the area.