Keystone Lintels Limited, a leading manufacturer of steel lintels was founded in 1989. An extensive range of Special Lintels are available which can be custom made to the owner's own specification. These include arches, gothic, parabolic, corner, splayed bay and sun lounge lintels. www.keystone-lintels.co.uk

With over 30 years experience in the specification, design and manufacture of steel lintels, Birtley Building Products stands at the forefront of technological change and innovation. www.birtley-building.co.uk