Matthew Hebden, Enfield, Middlesex, United Kingdom, offers the T-Pren gutter expansion material. On long metal gutters, the T-Pren forms an in-line waterproofing waterproof expansion joint and so overcomes the main problems of the standard “step” detail. The product has also been used as an expansion joint in copings, roof perimeters and walls. The T-Pren consists of two metal strips connected by a high-quality neoprene expansion joint. The connection is double vulcanized for longer life and the neoprene is resistant to ultraviolet rays and ozone, as well as industrial and marine atmospheres. It is also resistant to attack from timber preservatives, lichens and mosses. The product is supplied in 16-inch-wide-by-20-feet-long coils in aluminum, copper, lead, stainless, tern-coated stainless and zinc.