Pople Roofing

Valley Boards

Valley Boards if the shape of a roof requires a valley it is imperative that moisture does not penetrate at any point in the valley construction. To ensure this does not occur DPC will be installed along the length of the valley created.

This is then covered in Lead lining followed by an overlap of felt and then finally the tiles. Valley Boards are installed to support the weight of the DPC and Lead. Roof rafters are often notched to accept the new valley boards.

If not installed correctly the Valley is one of the most prone to leak areas of a roof as it is the area in which water is directed towards rather than away from therefore correct detailing and build is essential. A common misconception is that the mortar bedding will prevent water access, however, a valley should work even without mortar.

Timber Boarding

Softwood timber boarding is a traditional material used for the deck, It is important that the timber used should be;

• Natural species derived or preservative-treated in accordance with BS EN 599-1:2009
• At least 19mm thick
• Double nailed at each joist
• Loose or unsafe ridge tiles

Plywood for flat roof deck

Should be of at least marine grade and suitable to external users to BS EN 636 plywood boards used for the deck should conform at a minimum to;

• 18mm minimum thickness
• Double nailed at each joist
• Laid with staggered joints
• Provided with expansion gaps of 3mm between boards.

Replacing Roof Rafters

Roof rafters are structural timber sections that stretch from the ridge or hip to the wall plate, downslope or eave. And are designed to support the roof deck and coverings. A pair of rafters is known as a couple. In housing construction rafters are usually made from wood in some properties you will find that the rafters have been left exposed as a feature.

In modern buildings, preference has been made towards trussed rafters on the basis of cost and economy of the materials used coupled with off-site manufacturing and ease of construction.

Rafter and joist systems are made up of two sections that run directly below the roofing surface and give its shape, while the joists span the gap between the two rafter ends and support the whole thing. Over the years roof rafters can wear and rot and you may require a replacement. Replacing existing rafters without removing the roof requires carpentry skills.

Dormer Roof Construction

A dormer is usually made from wood. The main structural parts that form a dormer are the roof, side walls and front which faces outward.

Dormers and planning permission Planning is not required provided that basics are followed as detailed here.