Lead Flat Roof Construction

When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off.

Lead flat roof construction. Lead in use lead flat roof greyfriars roofing laid in stepped sections or bays to allow for expansion all joined by raised rolls. As you may imagine there is a fair amount of weight involved here in terms of boards felt etc. Rolled lead sheet is the only lead sheet produced to a. Associated lead mills ltd jamestown metals ltd.

The temperature of lead on a roof varies constantly. Correctly laid lead roof greyfriars roofing note the height of steps between bays the rolled joints and adequate overlaps problems. Used to join lead together into smaller pieces reduce expansion and contraction issues create up stands and troughs provide. Note no nails in the edge.

Traditional lead roof coverings are normally weathertight but not watertight. Lead can become damaged through. Old asbestos roofs are often replaced with flat roofs. Sizes of joists needed for flat roof construction.

The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. Lead flashings john gilbert used here to make a long lasting complicated junction lead worked to cover a skylight john gilbert a good long lasting repair typical problems. Cracking from being laid in such a way that. Having a manual for warm flat roof construction with details and a summary of rules to follow helps.

When a hot roof surface is suddenly cooled by rain the pressure in. On a low pitch roof where the lead isn t free to move it is more likely to buckle on expansion or stretch as it contracts. Others would treat even steeper pitches as flat roofs. A new lead bay fitted in a simple one piece bay like this one the lead is nailed into the upstand underneath the guttering the drip is then beaten nice and tight over the edge of the roof and trimmed to about 50mm.

Lead is commonly used for flat roofs because of it s long life and ability to be formed to fit many positions lead must be laid and formed correctly to achieve this long life however. 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. Accurately predicting the performance of a roofing material initially depends on the quality of the material concerned. Flat roof roll and drip intersections 42 pitched roof joints and.

British and european standard bsen 12588. More about lead as a building material. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.