Roofing Materials For New House Construction

Roofing Materials For New House Construction

The first material required in roof construction is timber. This may be a “cut” roof design whereby the whole timber framework is cut and built on site, or more commonly, “truss” which will use pre made A frames or trusses which are factory made and delivered to site.

A wall plate, a length of 100x75mm timber is cemented onto the top of the supporting walls to which the rafters and joists are fixed.

The trusses are placed at regular equal intervals to suit the type of load they are to carry. The heavier the load, the narrower the spacing or the larger the timbers used to make the truss. A normal spacing for roof trusses on an average house/roof is 600mm.

The timbers stay upright because they are tied together by binding timbers fixed to the underside of each truss. The end truss is fixed to the brickwork of the gable end to prevent a domino effect.

The rafters are covered in a layer of roofing felt or breathable membrane which is nailed to the roof trusses using galvanised nails, and it is upon this that the baton strips are nailed. This also helps the trusses bind together.

Roofing materials are usually carried around the construction site using a variety of construction machinery, from backhoe loaders to skid steer loaders, depending on the additional needs for plant and construction machinery on site.

Tiles or slates are the commonest type of topping to ensure a roof is weather proofed, which fix, or clip over, battens. These battens sit on the roofing membrane and are fixed to the rafters below.

The battens are fixed at regular intervals according to the gauge (distance between battens) specified by the tile manufacturer. This in turn will vary according to the angle, or pitch, of the roof.

Each tile must overlap the tile below it and this is the critical factor in working out how to tile the roof.

The frontage of the house immediately below the roof and the eaves is known as the roofline.

Modern construction now generally use plastics for the roofline.

Soffit is the thin board which is attached horizontally under the foot of the truss, and covers from the skin of the house to the facia board, a span which may be a few centimetres or, up to 3 or even 500mm.

The fascia board is vertical and covers the span between the eaves below the tiles and is nailed on to the foot ends of the trusses. It is generally 16-18mm thick, manufactured in 5metre lengths, the nails used to hold it will be plastic topped in the corresponding colour of the board.

Where the fascia runs up the gable end truss it is called a barge board, which covers over the exposed ends of the horizontal timbers.

The rainwater catchment, that is the guttering, is attached to the fascia under the lip of the lowest tiles and takes the run-off water to down pipes where it runs into the drainage system or soakaway.