Mathematical tiles or ‘tyles’ are a building material used extensively in the South Eastern counties of England during the 18th and early 19th Centuries. They can come in a variety of forms, from slate, to fired brick-like tiles, through to Terracotta. Although the brick tax (1784–1850) was formerly thought to have encouraged the use of mathematical tiling: in fact, the tiles were subject to the same taxation. It is estimated that there are only about one thousand buildings containing mathematical tiles in England, the earliest dated example going back to 1724.
The origin of the name is unknown, but this period was rich with symmetry and geometry conforming to Palladian principles of architecture: 16th Century architect Andrea Palladio’s work was strongly based on the symmetry, perspective and the classical architecture of Ancient Greece and Rome. Alternative names are sometimes given as brick tiles, geometrical tiles, mechanical tiles, rebate tiles, wall tiles, and weather tiles.
Mathematical tiles had several advantages over brick, as they were cheaper and easier to lay and ‘skilled workmen were not needed’, being pegged into position on to the framework beneath. The tiles were moulded with a lip on the reverse side enabling them to be fitted against battens in much the same way as roofing tiles, although they were sometimes bedded into mortar too. Mathematical tiles also became somewhat fashionable in their own right, as many medieval timber framed buildings were refaced with them. They also had the added advantage of providing excellent retrospective protection to the elements. Since mathematical tiles were unable to encompass right angles, the corners of mathematically tiled houses were usually dealt with in a differing manner, whether fitted with a painted board or quoined with brickwork to finish the tile courses.
Although the earliest examples date back to the early 18th Century, they were popular right through the 19th Century and are still specified in certain projects today.
Conservation and restoration of this building material is difficult only in that to access and repair/replace damaged tiles, the tiles need to be dismantled down (as they overlap one another) to allow them to be re-fixed.
A project we have recently secured has a number of repairs specified and we believe will make an interesting case study which may well feature in a forthcoming issue..