Mathematical tiles

Mathematical tiles have the appearance of bricks but are really tiles, hung upon wooden battons.  They vary in appearance – some are very difficult to distinguish from bricks (Image 1) but others lack the flat regularity of well laid bricks (Image 2).  Many walls present a mixture with bricks below and tiles above (Image 3).  In many instances timber framed buildings have been ‘modernised’ using mathematical tiles.  Images on this page show some examples – click to see their location.  Canterbury has an unusually high density of mathematical tiles, and these are particularly prevalent around the Buttermarket and Burgate Street.

A mathematical tile symposium held in 1981 produced the following facts and estimates:

  • we do not know how these tiles got their name – they have also been known as brick tiles, geometrical tiles, mechanical tiles, rebate tiles, wall tiles, and weather tiles
  • of the 859 examples then known in England, 321 were in Kent and 138 of these in Canterbury city
  • the earliest known use of mathematical tiles is 1724 – in Westcott Surrey
  • there appears to be no correlation between use of mathematical tiles and levels of tax on bricks or on tiles

So how can you tell whether a particular example is brick or tiles?  Here are some tests you can apply:

  • examine the edges of the wall (corners of the building or where the wall meets windows or doorways) – a tile version needs some device, normally a wooden strip, to mask the tile edging
  • see how flat and regular the face of the wall seems – an irregular surface suggests tiles or a very bad bricklayer!
  • on a hot day, feel the temperature of the surface (particularly where you suspect tiles above bricks) as bricks will take longer to warm up
  • if the building is old and has no brickwork at ground floor level, ask whether upper levels can really be true brick – if so, what is holding it up?

Sources:    Mathematical tiles (notes of Ewell Symposium 14 November 1981 chaired by Alec Clifton-Taylor) – copy held by British Library;  also Faversham Paper no. 25 Brick-tiles in the Faversham area by Terence Paul Smith