1 Sweep the floor thoroughly and check the general condition of the boards in case any need to be replaced. If so, try reclaimed boards.
2 Check each board is firmly fixed – any protruding nails need to be hammered below the surface. Prep the space by sealing any doors to stop dust escaping and make sure you have a dust mask plus clothes, eye and ear protection.
3 Using a professional sander, follow instructions for safety. Start by moving the sander diagonally across the boards. Then work up and down, going along the grain. Finally, use an edging sander to go over the edges of the room, and then a corner sander for any hard to reach nooks.
4 Sweep the floor, then repeat step three if required. Sand any rough spots smooth with sandpaper.
5 Before staining, clean the floor with methylated spirit, making sure the area is well ventilated. Choose your preferred type of varnish depending on how much wear and tear the room will receive. Then, using a 75mm paint brush, start staining the boards in line with the grain.
6 Once dry, sand out any rough spots and then repeat with second and third coats, if needed, until you have your desired finish.