TACS Information Sheet No. 1
Victorian encaustic and geometric floor tiles are usually made of fairly robust ceramic.
The most common problems encountered are;
Dull dirty appearance due to over a hundred years of wear and tear.
Paint spills and encrustation’s of other coatings.
Grease, oil or rust stains.
Ancient coatings of waxes and linseed oil which have absorbed into the body of the tiles and turned black.
Dirty and missing cement grouting.
Remember that any cleaning treatment on old floors is always experimental and is not bound to be effective, so with that in mind never start the cleaning process in the middle of the floor, always find an unobtrusive corner in which to test your method or product.
It is important not to over wet the floor as tiles could become loosened or a salt crystal reaction could be set up.
Where floors are in large open public buildings, with no other vulnerable building fabric in the vicinity, and all health and safety considerations have been taken into account, semi-industrial pressure steam cleaning can sometimes be a useful first phase, especially if the floor is in particularly bad condition.
In domestic or ecclesiastical buildings the best method of cleaning is by hand.
Recommended cleaning products are ‘Synperonic A’ and ‘Vulpex’ spirit soap’, available from conservation suppliers, or ‘HG Extra’, ‘HG grease remover’, or ‘BAL Ceramic Floor Tile Cleaner’ available from good tile suppliers.
All products are non ionic, ‘Synperonic A’ is a mild detergent with a balanced ph, ‘Vulpex’ is an alkaline soap, whilst ‘HG Extra (blue label)’ is a stronger detergent which contains phosphoric acid. HG grease remover is an alkaline cleaner and BAL floor tile cleaner contains sulphamic acid.
Whichever product is chosen, the tile should be pre-wetted, the product should be applied neat (with the exception of Vulpex which should be diluted) onto the surface of the tile and agitated manually, left for twenty minutes and then thoroughly rinsed off. The product should not be allowed to dry on the surface of the tile. Each tile should be given individual attention.
To agitate the detergent use ‘Scotchbrite’ green pan scourers. These are made of a plastic material which is abrasive enough to work the liquid into the body of the tile, but will not scratch the surface. Never use wire wool or any hard abrasive material.
Hardened substances which are on the surface of the tile, such as paint splashes may be removed using a ‘Stanley’ blade at a 45 degree angle, red plastic holders which hold the blade thus can be bought from hardware stores.
When the tiles are cleaned, regrouting is often a good idea. Clean new grout will often give the tiles a visual lift, it will also protect the edges of the tiles in areas of heavy tread. Weak cement grout is preferable to lime mortar grout as lime is likely to stain the tiles, however the choice depends on ‘like for like’ with the rest of the building. Rake out by hand all loose grout or dirt from the joints.
Never use bees wax or linseed oil as a protective coating.
Wearing of rubber gloves and eye protection are recommended against the effects of detergent splashes.
The above information is for guidance only. We do not accept responsibility as a result of any person carrying out any works according to the advice contained in this document.
Copyright: Lesley Durbin Jackfield Conservation Studio Sep 2007.