Roofs come in two main styles, pitched and flat. Each of these two styles requires different covering materials, although the basic framework is timber in both cases. If you are replacing your current roofing material, it is best to use a replacement similar to that which is already there. You certainly need to consider the weight of the new material and if the roof structure can support it. Flat roofs are usually felted, whilst pitched roofs usually feature tiles, slates or sometimes shingles.
Roof tiles, in one form or another, have been around for thousands of years. Originally, the tiles used on roofs would have come from the immediate area and would have been made of whatever material was available locally (clay, slate, stone, etc). Nowadays, roof tiles of every material, shape, colour and style are available all over the country.
Plain clay tiles are another traditional roofing material. Clay tiles are laid in a different manner to slate tiles. Each tile has two projecting lugs (called Nibs) on the back edge. These lugs took over the roofing battens and hold the tiles in place. The weight of the overlapping neighbour tiles stops the lugs from slipping off of the battens. Normally every fourth or fifth row of tiles will be nailed as well. As with slates, clay tiles overlap by about two-thirds. If you’re considering using clay tiles it is worth bearing in mind that the roof will need to be pitched at a greater angle (40 degrees compared to around 20 degrees on a slate tiled roof).
Often used on older houses, natural slates have become very expensive and are not as often used on new builds. It is possible to find second-hand reclaimed slates for smaller projects or replacements. Natural slates are held in place by nailing to roof battens. The slates we either have two holes at the top of the slate (head nailing) or two holes in the middle of the slate (centre nailing). The slates will overlap with both of these methods, covering about two-thirds of the slate below. This means that effectively the whole roof is covered by a thickness of two slates. If you’re considering using a natural slates, bear in mind that they are heavy, fragile and can have sharp edges. If you’re using reclaimed slates holes will already be in place, but new slates will need to be drilled.
Interlocking Concrete Tiles
Interlocking concrete tiles are probably the most common roofing material on modern houses. Like clay tiles, concrete tiles also a hook over the battens using lugs. However, concrete tiles also interlock with each other meaning less tiles are needed as less of the tile is overlapped. There are a variety of different interlocking tiles to suit different pitches of roof and building styles. It is also possible to get interlocking clay tiles although they are more expensive than the concrete variety.
Manufactured slate Tiles
Manufactured slate tiles are lighter, cheaper and far easier to lay than natural slate tiles. If you see a new building with what looks like a slate tiles on the roof, these will more often than not be manufactured slate tiles. Manufactured slate tiles are made from resin, sometimes mixed with ground slate. They are generally attached to the roof battens with clips which makes them very quick and easy to lay.
Other Roofing Materials
Aside from tiles, there are several other materials that you might find on your pitched roof.
Wooden shingles can be used to clad walls as well as being used as a roofing material. Traditionally, wooden shingles would be made from Western red Cedar as this type of wood weathers well. Wooden shingles are particularly suitable for steeply pitched roofs. Wooden shingles are attached to roof battens in the same way as natural slates.
Flashing, which is used to seal a joint between a roof and a wall (or window sill and wall), is often made from Lead in the UK. Flashing can also be made from Aluminium, Galvanised Steel, Zinc Alloy, Copper or Stainless Steel. Flashing is important as it stops water penetrating at the weak points in the roof where two different materials meet. The idea is that the flashing carries water away from the joint, and for the water to penetrate it must travel upwards. It is therefore important that the numerous sections of flashing on your roof are in good condition. Read our guide on removing, replacing or repairing flashing for more information.