Lead Flat Roof Construction Details

Investigative work carried out on warm roofs covered in lead has shown that in rare instances moisture can also be introduced by the development of sub atmospheric pressure in the roof space.

Lead flat roof construction details.

N gives a permanent flexible and waterproof joint. However it is important to follow the basic principles of sizing and fixings as indicated in the rolled lead sheet manual to reduce the effects of fatigue cracking or creep. Wood core roll as used on ridges hips and flat roofing wood core roll is to be used to allow for the expansion and contraction in lead sheet and flashing. Lead for the purpose fitting to a roof or bay window really starts at code 4 in theory if the roof is small enough you could use code 3 but this would normally be classed as a flashing lead i e.

An acid cure will give rise to white tains on the lead s n life expectancy of 20 years. N neutral cure product. When a hot roof surface is suddenly cooled by rain the pressure in. N avoids problems of cracking and lack of adhesion associated with mortar joints.

For roof detail the gauge of lead to be used will be dependant upon the application. Flat lead roofs should be laid with a slight fall. N cleaner quicker and easier to use than mortar with high adhesion to both lead and masonry. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.

Lead detail lead is commonly is used as a means to complete and help maximise the efficiency of a roof s water sheddings qualities. It is shaped to prevent wind lift. Thicker lead is used on longer bays joints along the length should be stepped to prevent rain seeping up through capillary action. N recommended by the lead sheet association.

Wood core roll is used for joining bays of lead roofing also on steeply pitched roofs and lead cladding where a bold joint appearance is preferred. N designed for lead masonry and lead brick pointed work. For additional stability you can also use steel joists that are built into one or both of the walls. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Our basic fitting guides are designed to assist installing rolled lead sheet in a range of roofing applications including flashings valleys gutters and flat roofing. Small over flashings or leak soakers. Traditional lead roof coverings are normally weathertight but not watertight. This will give additional stability to the roof structure.

It invariably can be found in a number of locations on a roof s profile and it s main function is to channel and deflect rainwater.