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EXPAMET
ESTABLISHED QUALITY 

Expamet encompasses a wide range of products designed and manufactured in Britain and trusted by generations of construction professionals.

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Windposts are designed to offer an alternative, cost-effective method of providing the additional stiffness that a masonry wall requires as specified by the Structural Engineer.

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BUILDERS METALWORK
BUILDING INDUSTRY EXPERTISE SINCE 1889

A wide range of straps, fixings, angles and brackets, wall starters, ties and reinforcement

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PLASTERERS ACCESSORIES
BUILDING INDUSTRY EXPERTISE SINCE 1889

Arch formers and accessories, plus beads in coated or galvanized metal, stainless steel and uPVC

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Masonry Support
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BAT Masonry Support is a range of bespoke systems designed to carry masonry cladding on steel or concrete structures.

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Permanent Slab Sofits

The permanent works design of the slab will have been carried out to relevant standards, and is outside the scope of this guide. The Hy-Rib, during construction of the slab, has to support the full weight of the concrete, together with the additional load from the operatives placing the concrete, known as the construction operations load. (See BS 5975 on Falsework (Ref. 17)). The safe span of the Hy-Rib, i.e. the clear distance between the supports, should not exceed the value given in the table below.

Although in soffit applications the deflection between the falsework supports is rarely critical, the likely maximum mid span deflection of the Hy-Rib is stated in table below. At end supports the Hy-Rib should have at least 50mm of bearing when seated on steel or concrete, increasing to 70mm on masonry (CIRIA C558 (Ref. 21)).  Note that this value is the deflection of the Hy-Rib between supports during construction, and not the final deflection of the completed slab after the falsework is struck / removed.

Indicative clear distance between supports for Hy-Rib used as permanent soffit formwork

Equivalent depth of the solid concrete slab Grade
2411
Grade
2611
Grade
2811
clear distance midspan deflection clear distance midspan deflection clear distance midspan deflection
mm mm mm  mm  mm  mm mm
75 950 5.4 800 3.8 725 3.5
100 875 5.2 725 3.6 650 3.3
125 825 4.8 675 3.3 600 3.1
150 775 4.5 625 3.1 575 2.9
175 725 4.2 600 2.9 550 2.6
200 700 3.9 575 2.7 525 2.5
250 625 3.4 525 2.4 475 2.2
300 575 3.1 475 2.1 425 1.9
400 500 2.5 425 1.7 375 1.6
500 450 2.1 375 1.5 350 1.3

 

Technical Support

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NOTES

The Hy-Rib is used in horizontal direction with the ribs pointing upwards and spanning in the strong direction between supports. In considering the permissible span of the Hy-Rib, the following loads have been included in the design:- the Hy-Rib self weight, It is assumed that the Hy-Rib is simply supported. Even if the Hy-Rib is spanning over several of the falsework supports, its lower bending strength at the support is such that it will yield as the full pressure is applied, making critical the bending at mid-span as a simply supported member. The anticipated midspan deflection of the Hy-Rib has been conservatively estimated using the self weight and the equivalent weight of solid concrete as simply supported; in practice the deflection is reduced by continuity. Where more than one Hy-Rib sheet is used to make up a span, there should be at least 75mm projecting past in both directions at the intermediate support with the lap. The minimum bearing of the Hy-Rib at end supports is 50mm for steel or concrete, increasing to 70mm when seated on masonry.

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Part of the Birtley Group

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.