How can splices be made in metal flashings? Can they be welded or soldered?
Soldering or welding metal flashings together is not recommended for long lengths of flashing. Such connections often break when the flashing expands or shrinks during temperature changes. Instead, metal flashings often are spliced by lapping sections about 6 inches, then bonding them together with several parallel rows of butyl sealant. Butyl sealant remains soft and gummy and permits movements to occur. Place four to five rows of sealant extending from the top edge of the flashing down and across to the projected edge of the flashing. Applying sealant in a side-to-side motion can create channels where water can flow through the lap. Splices also may be made using a folded seam, but the thickness of the seam may make bricklaying difficult. The brick that is set on the seam may ride up too high, or the edge of a brick may catch on the seam and push on it as the masonry undergoes thermal movements or moisture expansion.