There are lots of different parts to a thatched roof, so we’ve put together a quick and easy reference guide to help you identify the different parts as well as give you an understanding of what their purposes are.
Contents
1. Ridges
Block Finish
A Block Ridge is a section of thatch, normally around four inches thick, that is put on the top of the roof. Block ridges can be styled in a number of ways, whether that be straight cut, or a more intricate design incorporating diamonds, scallops or in some cases, complete free-standing sculptures!
Flush Finish
A simple, tidy method of ridging a thatched property, a flush ridge consists of sides that are flush with the surface of the other thatch. Common in Somerset and Devon, this method of ridging is suitable for most types of thatched roof.
Wrap Over Ridge
Wrap over ridges are formed by laying Long Straw, Combed Wheat Reed or Sedge Grass over the apex of the roof and wrapping it over before securing it down. Wrap over ridges tend to be more common than Butt Up ridges. Wrap over ridges can be finished in either the Block or Flush styles.
Butt Up Ridge
Butt up ridges are made up of layers of Combed Wheat Reed which are then butted up against one another at the apex of the roof. As Combed Wheat Reed is the only material that can be used for this type of ridging, it’s more commonly seen in the West Country. Butt up ridges can be finished in either the Block or Flush styles.
2. Fixings
Crooks
A crook is a thatching nail that is sometimes used to affix material to the rafters. Care must be taken when using crooks as they have a tendency to split rafters, especially on old timber. Due to the fact that crooks must also be hammered in, there is also a risk of damage to ceilings when they’re being installed.
Screws & Wires
Due to the disadvantages of using crooks in modern thatching, especially as thatched properties age, thatchers have moved on to using stainless steel screws, wires and metal rods to affix material to the rafters. This fixing method can increase the lifespan of the original timbers as the fittings don’t need to be hammered into the wood.
Spars
Spars can be made of wood or plastic and act like large staples that help to fix the thatch onto the roof. Wooden spars are often made from Hazel or Willow.
Liggers
Similar to Spars, Liggers are wooden staples made from Hazel or Willow and are used to create decorative patterns on ridges and at the edges of straw roofs.
Pin Wire
A pin wire is simply a piece of wire that is bent into a U shape and used to fix netting down onto a thatched roof.
3. Flashings
Flashings are used to waterproof certain areas of a thatched roof. You’ll also find flashing on tiled roofs as they’re an effective way of ensuring areas with high amounts of water runoff remain watertight. Common places for flashings on a thatched roof include between the thatch and chimneys, as well as under windows.
Flashings are usually made of lead or cement; lead tends to last longer, but you’ll tend to find cement flashings on Grade I or Grade II listing buildings. If you’re looking to change from cement to lead flashings and your property is Grade I or Grade II listed, you’ll have to apply for Listed Building Consent before carrying out the work.
4. Nettings
We’ve covered the use of nettings on thatched roofs in our guide titled “How long will a thatched roof last“. In the article, we mention that the main reasons for having netting on a thatched roof is to protect the thatch from birds and vermin, as well as to protect thatch that may be nearing the end of its life from slippage due to adverse winds.
Nettings are usually made from galvanised metal, although plastic and sometimes copper nettings are used. It’s believed that the use of copper netting reduces moss and lichen growth on thatched roofs.
Nettings are usually fixed to the roof using wires and spars.
5. Box Gutters
Box gutters are used where a thatched roof meets a chimney in order to transport water away from the joint and prevent water ingress into the property. They’re usually made of wood and covered with lead to make them watertight.