Stone Restoration Archives - Tile Doctor Lancashire

Black Limestone Floor Renovation in Lancaster

Clean and Seal of a Black Limestone Kitchen Floor in Lancaster

This customer from Lancaster contacted us about cleaning and sealing what they thought was a Blue Slate kitchen floor. Having spoke to them over the phone I arranged to pop over and survey the floor to get a better understanding of the work that needed to be done. Lancaster is a few miles South of our base in Carnforth and I’m always passing though.

Having visited the property I was able to confirm that the floor wasn’t Slate but Black Limestone which is notoriously high maintenance due to its acid sensitivity. I mentioned this and they were quite surprised as it had only been laid a few years earlier and it was sold as Black Slate. The two materials do look identical, but if you drop a small amount of something acidic on Black Limestone the stone fizzes and turns Grey and White.

Black Limestone Kitchen Floor Before Cleaning Lancaster

The big problem with Black Limestone is unlike Slate its very porous, this is why you see Slate being used for roof tiling and is still popular covering even to this day. Also, its very acid sensitive, so even Tea, Coffee, Juice, or Wine can mark it, so although popular in gardens it’s certainly not a stone we would recommend for use in a kitchen or bathroom.
Another problem you have is Black Limestone contains natural oils and it’s the oil that gives it that beautiful black colour. Once the oil is washed out of the stone over time or through the use of acidic cleaning products it leaves the stone looking grey and unattractive. This can be resolved however using an oil-based sealer but it is more expensive than a regular stone sealer.

Black Limestone Kitchen Floor Before Cleaning Lancaster

This stone is still workable though, so it’s not all bad news, with the right treatment it can look as good as the day it was laid (if not better) so I came up with a renovation plan that would do exactly that. They were happy to have the work done so we scheduled a date for the work to start.

Cleaning a Black Slate Floor Tiled Kitchen Floor

We find the best way to renovate floors like this is to use coarse diamond pads that can cut into the stone remove any surface damage, contaminates, old sealers and generally leave the stone very clean.

With this floor I started with a very coarse 50-grit DRB pad which is run several times over each stone using only water to lubricate the process. The process generates a lot of soiling and loose sediment that has to be rinsed off the floor with water and then extracted with a wet vacuum. Once this is done the process is repeated with a 100 and then 200-grit pad which together effectively re-hone the stone and remove any scratches caused by the previous pad. A dilution of Remove and Go was also used with the 200-grit pad to ensure the tiles were clean and any remaining sealer not caught by the pads had been removed.

The last step on the first day was to re-point the stone tiles where needed to remove failed and crumbling mortar. This was then left to set hard overnight so we could continue with the renovation the next day.

On day two we followed up the renovation of the stone by moving onto finer Burnishing pads starting with a 400-grit diamond pad applied in the same way and rinsing and extracting afterwards. This was followed by the application of an 800 and then 1500-grit pad to further refine and improve the stone.

Sealing a Black Slate Tiled Kitchen Floor

The following day the Black Limestone was sealed with a coat of Tile Doctor X-Tra seal which is the Oil based sealer I mentioned earlier. It brings out the true colour of this stone and the seal leaves a sheen appearance to give a very appealing finish. We find one coat is usually enough for this sealer as it’s a lot thicker that other sealers.

Black Limestone Kitchen Floor During Sealing Lancaster

Before leaving I talked through aftercare cleaning with two buckets and the importance of using a pH Neutral cleaning product. We recommend avoiding steam cleaners and not to use cheap bleach or acidic cleaning products which can damage the sealer with repeated use.

Black Limestone Kitchen Floor After Renovation Lancaster

We always encourage feedback from customers, and I’m pleased to be able to quote the following message they left on our feedback system:

Great service very organised and professional service would highly recommend

Black Limestone Kitchen Floor After Renovation Lancaster

Professional Restoration of a Black Limestone Kitchen Floor in Lancashire

Clean and Seal of a Black Limestone Kitchen Floor in Lancaster Read More »

Renovating Flagstones Covered in Concrete Screed and Bitumen in Carnforth

The owner of this Flagstone floor at a property in Carnforth was told by a damp specialist to remove the carpet and underlay and have the floor taken out and skipped. Then to install new hardcore and concrete put in place but with a Damp Proof Membrane installed in between, then once fully cured (four weeks at least) they could have a new carpet, tile or wood floor etc. installed. All good advice, however, the owner of the house wanted to keep as many original features as possible and wasn’t keen on the proposal.

Looking for an alternative solution they reached out to Tile Doctor and so I went over to take a look. After surveying the floor, I came up with a completely different solution which involved milling the stone with coarse abrasive pads to remove the screed and bitumen and then resurface with diamond encrusted burnishing pads of medium and fine grits which would result in a smooth finish. Not only would this be much easier to clean going forward it would also be much more attractive, especially once sealed.

Flagstone Floor Before Renovation Carnforth

Happy with our alternative we arranged a date to come and do the work which would take three days, two days to prepare the floor and a third to apply a sealer.

Cleaning a Flagstone Tiled Ground Floor

Milling a floor is arduous work and requires the use of a heavy rotary machine that can apply weight onto the stone so the milling pads can really get a bite into the surface. Because of this I roped in a colleague to help take some of the strain. Some of the areas of bitumen and screed were so prominent we used an SDS hammer action drill with a flat bit to chisel them off first, this can leave a few marks in the stone which we then level out with the milling pads starting with a 50 grit and go all the way up to a 400 grit

Flagstone Floor During Renovation Carnforth

We used a lot of water during this process to help lubricate the abrasive action of the milling pads, this also helps to rinse off the soil that is created, all of which is extracted with a wet vacuum.

Next step is to give the floor an acid rinse with Tile Doctor Grout Clean-Up which is designed to neutralise any alkaline salts in the stone that could result in efflorescence later.

With the floor cleaned up the last step was to re-point between the Flagstones using a breathable pointing product called GFtK 800.

Flagstone Floor After Cleaning Carnforth

Sealing a Flagstone Tiled Ground Floor

Sealing was the next step however the floor was still quite damp after the initial renovation, so it was left for a few days to dry out first.

We selected a fully breathable sealer for this floor, this is an important requirement for a floor with no damp proof membrane as it will allow moisture to rise through the flagstone and evaporate at the surface. The concrete screed and bitumen covering will have prevented this previously which is dangerous as a build up of moisture in the stone can lead to it crumbling and you risk moisture reaching out to the walls where it can lead to rising damp.

Tile Doctor has three breathable sealers to choose from and in this case the customer decided to go with Tile Doctor Colour Grow which is an impregnating sealer that protects from within and enhances the natural colours in the stone.

The floor was completely transformed by the end of the third day, you would not have known it was the same floor. It was now clear of all the previous coverings and now looked like a characterful old Flagstone floor should.

Before leaving I recommended, they use Tile Doctor Neutral Cleaner for everyday cleaning, being pH neutral it won’t prematurely erode the sealer allowing it to work for longer. I also advised that it’s possible that parts of the stone may go a shade darker in winter and a shade lighter in summer due to the moisture rising through the floor.

Stone Restoration