LEADWORK

The word flashing is derived from the word flash meaning a sudden rush of water (i.e. flash flood). Lead sheet is the best material for flashings and weathering. Lead sheet is extremely malleable and can be easily dressed to fit the multi curved contours of many modern roofing tiles. To ensure the long life expected from lead flashings, the fixing method of  lead sheet needs careful consideration. Lead is a very soft metal and will therefore expand and contract readily according the to temperature of its environment. Failure to allow for this movement with result in distortion of the lead and subsequent cracking thru fatigue. For this reason lead sheet is laid in sections, each section with a maximum length according to the code size. The code size refers to the thickness of the lead. 

Apron flashings are used at the head of a lean to roof where it abuts a wall or at the base of a chimney stack. A groove referred to as a chase is cut into the brickwork joints. Lead sheet of an appropriate width is folded into a 'L' shape. The top edge of the lead is bent back approximately 25mm. This edge is placed within the chase. The lead can be fixed with lead wedges not more than 500mm apart. The lead can be dressed and bossed to fit snugly over the roof tiles/ slates and the chase pointed with mortar. Code 4 lead is most commonly specified and should be laid in section of not more 1.5 meters in length.

Cover flashings are used at sloping abutments such as party walls and the sides of chimney stacks. A groove referred to as a chase is cut into the brickwork joints. Lead sheet of an appropriate width is folded into a 'L' shape. The lead is placed against the wall foe making out. The individual steps are marked, cut and the turn in of each step folded. The turn in is placed within the chase in the brick work and fixed with lead wedges. The lead can be dressed and bossed to fit snugly over the roof tiles/ slates and the chase pointed with mortar. Code 4 lead is most commonly specified and should be laid in section of not more 1.5 meters in length.

Soakers are only used with plain tiles and slates (double lap tiling/ slating) and are used at sloping abutments such as party walls and the sides of chimney stacks. Lead sheet of an appropriate width for the roofing material is cut to the required length and folded into a 'L' shape. The top of the soaker is further folded down  over the top of the roofing material. One soaker is required per course of roof tiles/ slates at the abutment and are fitted as the tiles/ slates are fixed. Once the soakers and roofing material are fixed a cover or stepped cover flashing are fixed which needs only to cover to soakers and not the roofing material. The length of a soakers can be determined as follows:  Gauge plus Headlap plus 25mm.