For me, writing ‘everything you need to know about floor sanding’ is probably the hardest topic I’ve covered so far. It’s something that I have done for more years than I care to admit, sanding thousands of floors of all ages and wood species, and it is simply limitless as to what to write and where to begin. To keep this article from overrunning I will keep it as simple as possible, so if you would like further help or information, don’t hesitate to give me a call.
For Alresford Interiors and I there are three manufacturers of machines that we use for floor sanding works; Lagler, Festool and Fein. These machines are used by many professional floor sanding companies and either carry dust free classifications or are plugged into dust extractors, reducing the level of dust to virtually zero. The machines we use from these manufacturers are the Lagler Flip, Hummel and Trio, the Festool RO150 and RO90 and the Fein Multi master.
There are many ‘grits’ of sandpaper available, from 16 right up to 2000 (the lower the number the coarser the paper), but for sanding floors we generally use 24-120 grit. It is important to select the right grit for the floor. You need to be using a coarse enough grit to take the old finish off the floor, but too coarse and you use extra time sanding with finer papers. Equally you don’t want to use a paper that is to fine as this will clog quickly and taking longer to sand. Knowing what grit to use comes with a little common sense and a lot of experience.
We’ve completed countless sanding courses over the years and were the first company in the UK to be trained by Lagler. There are always situations where things have to be done differently, such as not using the same grit sequence. Every company has its own preferences, but generally speaking the process is the same: Always make sure the floor is thoroughly swept and vacuumed before starting and any high nails have been punched under. It is also very important to vacuum after each sanding grit is changed, as this will keep the scratches to a minimum.
We always start with the Lagler Hummel, working from left to right. This is a serious bit of kit and it’s important to keep it moving when the drum is down (paper is in contact with the floor) as leaving it stationary will result in gouges being left in the floor (a common mistake for amateurs). Generally speaking we start on a 40 grit paper, working along the grain as much as possible on a plank floor. On a parquet floor we will work at diagonals and never sand directly across the grain.
The next step is the edges. For this, we use the Lagler Flip (generally using the same grit paper that was used with the Hummel) working in a clockwise rotation around the room. Again it is important to keep the sander moving as it is very easy to create gouges around the edges. This is a very powerful sander and needs to be treated with respect.
Repeat steps 1 and 2 with 60 grit paper and never drop more than 2 levels of grit. For example you wouldn’t start on a 40 grit paper and use a 100, or even 80 grit paper next.
With the hardest part of the job done, it’s time to move onto the finishing sanders. Remember that you are trying to make the floor smoother and eliminate scratches, so be sure to keep a very close eye on what you are doing as marks and scratches can show up when the finish is applied.
First we use the Lagler Trio on a 60 grit, which can be used in any direction on the floor (but generally we would start at one side of the room working our way up and down each board so you know exactly where you have been). Change the grit to 100, remembering to vacuum the floor, and commence sanding.
Next step is using the Festool Rotex RO150 with 100 grit paper for the edges. This step will eliminate any small scratches hard up against the skirting boards that have been left by the edging sander and couldn’t be reached with the Trio.
The floor by now should look drastically different from when you started and there are only a couple of steps to go.
We sand the corners firstly by scraping off and dirt and grime with a small scraper or chisel. They are then sanded with a Fein Multi Master finishing on 100 grit. The whole floor should be thoroughly vacuumed and remember to make sure you go around the base of the skirting as it is amazing how much dust and grime can get under them.
Last sand is done with the Lagler Trio with a 120 grit paper this will leave a very smooth finish. A really good vacuum is then required prior to finishing and also be careful what you have on your feet, as black rubber soled shoes can leave marks!
I hope this has been helpful! If you need any help or advice please do give us a call on 01962 733016 to discuss your project – we can either do the work for you, or you can hire the machines from us.