Most hire shops will have a floor sander available which can really do an excellent job.
One word of caution though, they are powerful, noisy and a lot of dust will be generated.
Always ask for advice from the hirer on how to use their particular machine. And get an adequate supply of sanding belts, which are usually supplied on a sale or return basis. You will also need to hire a smaller edging machine.
Prepare the floor
Before sanding the floor, empty the room completely. Go over the entire floor and remove any small tacks which have been used for fixing previous coverings. At the same time, use a hammer and nail punch to recess all the floorboard nails below the surface. If you don’t, they will simply shred the sanding belt as it passes. Sweep the floor and then plan your work before starting.
Wear suitable protective gear – dust mask, goggles and ear defenders. Whilst sanding is best carried out in the direction of the grain of the boards, uneven and very soiled boards should first be sanded diagonally with the coarse belts. Once complete, they should then be sanded in the grain direction using gradually finer grades of sandpaper
Sanding the floor
Start at one side of the room with your back to the end wall.
Do not lower the sanding plate whilst stationary as this will cause the sander to eat into the boards more than required.
When ready, switch on the machine, taking adequate care to keep the flex away from the sander.
Lower the plate and walk the machine along the boards at a steady pace. At the end of the first ‘run’, before hitting the skirting board, walk the machine back to your starting position. Move across the room repeating this process. Once the entire floor has been treated in this way, you will have an area at one end which was not sanded. Turn the machine to face the opposite direction and treat these areas with a similar back and forth pattern, blending in to the previously cleaned areas.
This whole process will need to be repeated until the floor has a uniform look. Then repeat using gradually finer grades of sandpaper to achieve a smooth finish.
Sanding the edges
Now, you will need to treat the edges. This is where the edging machine comes into its own. This small sander will enable you to work up to the skirting edge without damaging it. Work your way along all the edges, gradually using finer grades of paper until they blend with the main area.
Cleaning up ready for varnishing
Once sanding work is complete, vacuum up all of the dust. It is a good idea to then allow the air in the room to settle for an hour or so before repeating this. You’ll be surprised how much more dust you collect the second time.