PLAIN TILES

Plain tiles are one  of the most traditional roof coverings found in the south east. Many of the historic buildings in this area are covered with 'Kent pegs' the oldest form of plain tiles and  are still manufactured today. These tiles were made from clay by hand, and it possible to find tiles with the imprint of the hand that made them. Usually the tiles are 255x155mm in size however some tiles do vary in size. The tiles are basically a rectangle slab of fired clay with two holes at the top.  Through these holes oak dowels were inserted referred to as pegs, hence the name. The tile then could be hung from a batten on the roof without further fixing. Today all manufacture plain tiles in a standard 265x165mm size either in clay, handmade or machine made, and more commonly concrete. Modern plain tiles are made with nibs on the back of the tiles so that tiles can be hung on a batten with the need for pegs to be inserted. The holes have been retained although a much smaller sized so that the tiles can be fixed with an apposite nail. Their small size and the availability of a large amount of varied fittings and accessories allow details and effects to be achieved that could not be done with any other roof tile. A standard specification would call for plain tiles to be fixed in every fifth course with two 38mm aluminum alloy nails to 25x38mm tanalized battens fixed over BS 747 1F roofing felt.

Prior to any work at the eave consideration should be given to installation of a ventilation system. The roofing underlay should drain any rainwater into the gutter. Any water traps behind the fascia should be avoided. The first tile batten is positioned so that the roofing tiles drain water into the centre of the gutter. The first course of tiles to be laid are called eave/ top tiles. These are purposed made tiles that are shorter in length, which are to maintain a headlap on the first course of plain tiles and should be fixed with two tile nails. The first course of plain can now be laid and  again should be fixed with two tile tiles.

The ridge tiles are usually the last part of a roof to be completed. The last course of tiles to be laid are called eave/ top tiles. These are purposed made tiles that are shorter in length, which are to maintain a headlap on the last course of plain tiles and should be fixed with two tile nails. The ridge tiles are then bedded into a mortar which can be coloured to match the colour of the roof tiles and pointed to give an even appearance. Ridge tiles should not be solid bedded. The tiles should only be bedded at the edges of the tiles to prevent shrinkage of the mortar

The roof battens should extend on to the outer wall. A fibre cement undercloak is inserted between the top of the wall and the battens. The purpose of the undercloak is to close of the cavity wall and to support the bedding material. The undercloak should extend over the wall between 38-50mm.  The roof tiles can be bedded in a sand cement mortar that should be coloured to match the colour of the roof tiles. Tile and half tiles are used in alternate courses to maintain the broken bond of the plain tiles. All tiles at the verge should be fixed with tile nails. Upon completion the excess mortar can be struck off and pointed for a neat finish.