A roof can be described as the covering of a building which provides protection against the elements to make is weathertight.
When building a new property, the roof design may be decided at the point the planning consent has been given. Some planning departments may put conditions on the roof such as it has to be inn-keeping with neighbouring properties e.g. ridge heights, pitch and using the same materials. You need to ensure you understand the requirements as they could increase the cost of the project (having to use slates rather than concrete tile).
Trusses:
These are made off-site to the calculations provided by the building regulations. They are then delivered to site and put into place by the joiner. Trusses are used when the loft space isn’t planned to be used as a habitable room as they require a shallower pitch. The advantages of using trusses are that they are relatively cheap, quick and easy to put together. Large developers normally prefer this option as it also keeps the cost of labour down.
Cut:
These are made up on site using traditional engineering and joinery skills. It is important to have skilled tradesmen performing this task as it could be a complex process. This option is also good for complicated roof shapes such as dormers or if you are planning to use the attic as a habitable space. You would be able to build the roof shape to how you require it, rather than to a conventional shape. This preference also allows your roof to offer internal design features such as a King post which would offer another aesthetic component to the build.
Materials
Different roof pitches require different roofing materials to be used. Metal works best for extremely shallow roof pitches where as a not so shallow pitch will require a heavier interlocking tile. Standard pitches are able to use a range of tiles such as slate or concrete tile (please note that the material could be pre-determined at the planning stage). It is a good idea to ask your roofer to let you know how many roof tiles you would need per square metre and this will give you an idea on the cost and may then influence your decision of what material to use. Your architect / building inspector would be able to advise on the correct roof material to use.
Process:
Roofers will normally attend site between the tenth and twelfth week and should be there between one and a half weeks depending on the roof material chosen.
It is important to get few different quotes to ensure you’re not overspending. Also, ensure you choose a reputable company as laying a roof is a specialised skill.
- Cover structure with underlay
This is normally a type of felt and is placed under the exterior roof which works as a shield to protect the thermal insulation material and building structure from the elements. The underlay works as a secondary roof under the primary roof to prevent water getting in.
- Measure the structure for roof riles and battens
Battens should be fixed to rafters at set at centres not more than 600mm apart. They should also span at least three rafters and be at least 1.2m long.
- Install the battens
Nails should usually have a diameter of at least 3.35mm and should provide a minimum of 40mm penetration in to the rafter (nail length of 65mm is ideal).
- Lay the tiles
Lay a course of tiles along the eaves and mark the position along them as well as every third line of the battens. Some roofers also spray a chalk line from the eaves to the ridge, so the vertical lines remain straight.
- Install the verge units
The verge is the edge of the pitched roof as it meets the gable end. These verge tiles are normally mortared to prevent rain and wind from getting underneath and damaging the structure.
- Install the roof ridge
The ridge is the highest point on the roof and is where the two roof areas intersect.
Disclaimer: The information in this website is for general guidance and is not legal advice. Specialist legal advice should be taken in relation to specific circumstances.
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