First of all, I really have to say that sanding a wood floor is a job where it is very important that it is done well, but very easy to do badly. For this job, more than almost any other I have seen or spoken about, the peace of mind that comes from hiring the professionals is worth paying for, in fact it is fantastic value for money. However, if, for whatever reason you are determined to do it yourself, here is how it is done:
Step 1 - Sanding:
This sounds obvious and simple but it isn't. While you can sand a floor with any type of sanding machine, including the human type, to get the best finish it is recommended that you hire a modern orbital sander. You will also need the four grades of sandpaper, 36, 60, 80 and 100.
First put on the roughest grain (36) and sand the entire floor once using long strokes, always being careful to sand with the grain and never across it. Next, attach the finer grain (60) and sanding wood floor again, this time paying close attention to smoothing out the scratches left by the rough paper. Then sand the floor once with the two remaining grains, in order of roughness (80 then 100) and you should have a nice evenly smooth finish.
Step 2 - The Cleanup:
See all that saw dust that you have created? Well, now you need to pick up every single tiny bit of it before moving onto the next step. It is recommended that you use a brush, and then a hand-held vacuum.
Step 3 - Finishing:
Now you can see why I was so particular in telling you that every single dust particle must be lifted, unless you fancy seeing it through a coat of woodstain, ruining the finish of your floor.
Of course not everyone decides to use woodstain; many people prefer the natural look. If you are one such person you can move onto step 4. If not...
The first step in staining the floor is to test your shade on a corner of the floor - leave it 5 minutes to dry, to make sure you like it on.
If you do: the next step is to apply a first coat of stain to the rest of the floor. Use a brush and smooth out with a rag if you want heavier, darker coats. Use only rags for lighter and more controlled strokes. Either way, apply with long, even strokes, going with the grain. Allow the first coat to dry. If necessary, apply a second coat, and/or touch up light spots.
Step 4 - Sealing
James Bond likes his Martinis shaken not stirred, but when it comes to the Polyurethane substance used as a surface (sealing) coat for wood flooring, it is essential that it is stirred, not shaken before use, as shaking would cause air bubbles, and, potentially ruin the finish.
Apply polyurethane with a brush or roller, using smooth, even strokes with the grain to avoid marks in the finish. Then (check the label for drying times of the brand you have bought) leave to dry for at least 3 hours, before applying the second coat. The second and final coat should be left to dry overnight, and for up to 3 days before furniture or rugs are replaced on the floor.
