Are they bricks? Or Mathematical tiles?

Are they bricks? Or Mathematical tiles? 

During the seventeenth and eighteenth centuries, with the increasing production of bricks, it became popular to modernize old timber-framed houses by providing a new false brick frontages. It is a common feature in the south-east to encase or largely encase a timber frame in brick to ‘improve’ and ‘modernise’ the façade of the building to reflect the modern trend of brickwork on the façade of the building.

This is often missed by the passer by in the street of most of these buildings. The appearance of bricks make the observer think there is a brick façade, this effect seems to be increased with the façade being painted as can be seen in a street scene as can be seen in the photo below.

A street where the upper floors are all mathematical tiles

A lot of people mistake these tiles for real bricks, this is the intention of the mathematical tiles!

The real clue in distinguishing tiles from bricks is that the tile just look like tiles, bricks need to sit upon a load bearing surface, this usually would consist of a beam of some description, and the giveaway for mathematical tile is that the “bricks” are not supported by a visible beam or base wall. This may sound odd but when you see a first or second floor with “bricks” which would be technically very difficult to achieve as you would need to place the bricks on some form of wall plate or beam.

Left is a brick façade, right is a mathematical tiled façade. Note the lack of supporting beam on the right hand side.

The other typical giveaway is the evenness of the tiles, these have often either been poorly hung so that the tiles are uneven which reduce their effect as brickwork. The timber frame may also move over time which makes the tile move, the uneven angle of the tiles would often be impossible with a brick wall.

 Note on this façade that the tiles simply hang down at the base of the 'brick' wall.

Note the classic example of a mathematical tiles upper storey where it would be very difficult to make  a traditional brick façade work, note the lack of supporting beam and unevenness of the tiles.

Above and below is the view of the side of the top storey of a building where the budget would only allow for the mathematical tiles on the front elevation not the side, here ordinary tiles would need to be sufficient.

We had a project recently where an eighteenth century timber frame had extended a medieval building and this extension had introduced mathematical tiles to the main facades to portray a ‘modern’ appearance and the look of brickwork. When we became involved in the project the house had been neglected for many years, the extent of the tiles were clearly visible due to the base of the wall where the tiles hung below a wall plate.

The front elevation of the timber framed 18th Century house, with mathematical tiles on the front and side facades. 

Above and below are wonderful photos of the building as we found it, however it does show the cross section of the mathematical tiling, showing how it is fixed with the timberwork and the lime mortar.

Repairing these and re-hanging the existing tile was interesting, as can be seen it was a careful process to re-hang the tiles. The tiles were re-hung with the tile nailed into the timber substrate, through a breather membrane, an NHL2 lime mortar pugging was then used to bed the tiles down, this also provided the basis for the pointing of the tiles to create the brick effect.

As can be seen from the drawing above the timber frame has a timber boarding or battens fixed to the façade and then the tiles are fixed to this.

In this instance we used a boarding as a base to fix the breather membrane and the tiles, with the NHL2 pugging.  

Photo above showing the tiles being fixed and pointed as they are pugged in place. 

A finished section of the front façade, this still shows the 'hanging' brickwork at the base which shows that it is tile hung.

The front elevation nearing completion.