What’s on your roof?
There are various roof types but all can be classified into two main categories: flat or pitched. Incidentally flat does not mean horizontal, but is defined as having a pitch of less than 10% to the horizontal. So a flat roof may not be flat – got that? OK, moving on.
The most common roof, certainly in the UK, is the pitched roof. These can vary between methods of construction in terms of the wooden construction (the bit that holds it up) and also the roof covering (the bit that keeps the rain out). They all have certain components in common, though, and these are some of the terms you might hear bandied about by your roofers.[lg_slideshow folder="Bungalow/"]
Barge Board: Nothing to do with narrow boats. This is a board fitted on the end of a gable roof just beneath the edge of the tiles/slates and following the slope of the roof from the ridge to the eaves.
Batten: Long strips of soft wood to which roof coverings or plasterboards are usually fitted. When used to support roof coverings, battens are fixed to the rafters and referred to as roof tile battens. As in: batten down the hatches.
Collar: Horizontal timber tie attached at each end to opposite rafters in a pitched roof. Without a collar, the weight of the roof can push the walls apart. Collar and tie, geddit?
Covering: The external material laid or fixed on a roof to protect the building e.g. slates, tiles, zinc etc. and any combination thereof. This is the bit that keeps the rain out.
Eaves: Means ‘edge’ and the eaves of a roof is its lowest edge.
Fascia Board: External horizontal timber board attached to the ends of rafter feet to which the gutter is fixed.
Flashings: Not performed by rude roofers. These are narrow pieces of lead that are required at the intersection between the vertical faces of walls or framing and pitched roofs, flat roofs, gutters etc. to prevent moisture ingress.
Flaunching: Cement mortar filler on top of a chimney stack at the base of chimney pots or protruding flues.
Gable: Triangular upper part of wall at the end of a ridge roof. As in: gable end.
1) Floor Joist: A bearing timber forming part of a suspended timber floor to which the floor boards are nailed to the top and a ceiling may be attached beneath or
2) Ceiling Joist: A bearing timber spanning an area to which a ceiling is fixed to the underside only.
Parapet: A low wall that projects beyond the eaves at the edge of a roof.
Pitch: The slope of a roof.
Purlin: Part of internal roof construction. A horizontal timber beam, providing intermediate support to rafters. Not to be confused with knittin and purlin to make woolley jumpers.
Rafters: Part of the basic internal construction, you may also hear them called common rafters, they are wooden spars rising from the eaves to the ridge. They mark the extent of the roof space, hence the expression full to the rafters, meaning it can’t get any fuller.
Ridge: The highest point of a pitched roof at the head of the rafters.
Ridge Tile: A purpose designed tile that covers the ridge of a pitched roof.
Roof Truss: Quite common until the 1920s the function of a roof truss is to support the purlins. Sometimes found in very large buildings where big rooms resulted in few load bearing walls. More recently a roof truss means a prefabricated structural timber framework delivered to site to form part of a roof.
Roof Void: The space beneath the roof structure and above the ceiling joists of the uppermost room(s) in a building. In other words, the attic or loft.
Sarking: Boards nailed to the upper edges of rafters to which slate and other roofing materials are secured.
Sarking Felt: Waterproof material, supplied on a roll. Fixed beneath roof tile battens when laying a new roof or recovering an existing roof.
Soffit: The visible covering of the underside of flight of stairs or a projecting surface such as projecting eaves of a roof.
Spars: Part of roof construction. Sometimes referred to as Common Rafters. Similar to joists but inclined rising from the eaves (foot) to the ridge (head) to support a pitched roof covering.
Strut: Your stuff. Intermediate supporting timber for a purlin.
Valley: Formed by the intersection of two roof surfaces having an external angle less than 180º. The wood member at the intersection is called the valley rafter and the feet of short spars are nailed to the valley rafter.
Verge: The edge of a roof which runs from eaves to ridge at a gable.
1) Part of a pitched roof construction that receives the feet of the spars (rafters) and ceiling joist ends.
2) Part of a flat roof structure that receives the ends of the flat roof joists.
3) Part of a suspended timber floor construction that provides a level bearing and fixing point for the joists and uniformally distribute loads from the joists to the wall below the plate.
I hope that helps!