How is a wall constructed?
Measure the inner leaf thickness, cavity width & outer leaf thickness. Birtley recommends the use of an additional cavity tray with all external cavity wall lintels.
• Single leaf face brick or block external walls.
• 200-215mm solid brick or block walls.
• 215mm fair face solid walls with two leaves.
• 100mm and 140mm load bearing walls
• 100mm Non-load bearing walls
Measure the cavity width & the outer leaf thickness.
How wide is the opening?
The opening that will contain the window or door.
The Lintel: Should be minimum 300mm wider than the opening (150mm at each end) Except when noted otherwise.
How much weight is above the opening?
To determine which load duty is required, the imposed load must be fully assessed and quantified.
Loads can be direct e.g. walls/floors/live loads, or indirect, from adjacent parts of the structure – for which a proportion must be taken into account. Imposed loads should be derived in accordance with PD6697/BS5977, and unfactored when compared with our published Safe Working Loads (SWL).
Birtley began life as Birtley Building Products in 1965, based at the current site in County Durham. Originally a steel fabricator for the area’s mining and power generation industries, the company made its first steel lintels in 1967. Since then, Birtley has grown from reliable local supplier to a UK-wide force in construction design technology and product development.
In 1889, the British Metal Expansion Company was established in Hartlepool. It had sole European rights for the manufacture of expanded metal mesh, mainly for use as reinforcement and lath in the rapidly expanding sector of concrete construction. The business that grew from these early days later changed its name to Expamet.
Acquired by Birtley Group in 2015, Bowater Doors is a nationally-known name synonymous with top quality and imaginative composite residential door design and manufacture.
The product portfolio offers exclusive ranges for trade installers and a retail range providing doors direct to consumer and social housing organisations.
Birtley Galvanizing boasts one of the most impressive galvanizing plants in Europe. The plant achieves the finest quality hot-dip galvanized zinc protective coatings to BS EN ISO 1461. Using state-of-the-art technology the plant processes steel products using a computer controlled, automated handling system, enabling Birtley Galvanizing to provide full project solutions to many industries.