The pictures below are of a 12m2 Sandstone Flagged floor at a property in Preston where the surface of the stone was flaking off. The floor looked terrible and more importantly my customer mentioned that visitors had occasionally tripped on the uneven stone, and this was causing some concern.
Another job which we agreed to do was to knock out the old pointing (what there was of it) and apply fresh. With the Sandstone flagstones smoothed, new pointing and stone sealed the floor was going to be transformed and unrecognisable once completed.
Milling a Flaking Sandstone Flagged Floor
Milling Sandstone flagstones involves the use of a set of thee coarse millings pads of different grades (50, 100 and 200 grit). They are applied to the stone in sequence beginning with the 50-grit pad and applied using a weighted heavy duty floor buffer. This generates a lot of dust, so water is used to lubricate and keep the dust down. During the process the water turns into a murky brown slurry which needs to be rinsed off and extracted using a wet vacuum as you go.
With the shaling removed it was then a question of polishing up the surface of the stone with the finer 100 and then 200-grit milling pads. Again, water is used to lubricate and capture the dust created during the process and then rinsed away and extracted with the wet vacuum.
When it comes to repointing old flagstone floors, I find a lot of builders and tilers I speak to usually recommend Limecrete or similar which is staple for old floors as its breathable, but I find it difficult to work with and it takes a long time to cure fully. Another problem is every time the floor is given a decent clean, some of the White Limecrete rinses out and into the stone.
Personally, I like to use a German product called VDW800, its fully breathable, has a reliable working time, its easy to apply and does a great job. I’ll put a link to a video about it in this post so you can see how to use it. It’s not a Tile Doctor product but I’m more than happy to endorse it.
Sealing Flagstone Floor Tiles
The stone and fresh mortar was left to dry out for 48 hours to ensure it would be dry before completing the last stage of applying a sealer. Before starting with sealing, I gave the floor light clean to remove any loose mortar from the pointing.
One done I sealed the sandstone using several coats of Tile Doctor Colour Grow, which is an impregnating product that soaks into the pores of the stone and occupies that space preventing dirt from become ingrained. Colour Grow as its name suggests also improves the appearance of the stone by enhancing its natural colours. The sealer also leaves a matt finish, which is a perfect match for the rustic character of the old stone.