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Q – What is a Dead Load Structure?

5th February 2014

Dibsa Dead Load StructureA – A Dibsa Dead Load system is a series of lightweight steel members, delivered to site in kit form for fitting directly onto the existing roof –  think along the lines of Meccano for Adults.

Our dead load system is predominantly used when carrying out flat to pitch conversions as the system is fully adjustable to allow for any plant or undulations on the roof itself.

It consists of a base member fixed directly to the existing roof with height adjustable props fixed onto it, followed by a rafters and purlins (dependant on the selected roof covering).

The reason we call it a Dead Load system is that the weight of the structure is transferred down through the existing roof as a dead weight. It is therefore important to ascertain the composition of the existing roof as our structure is not suitable for installation onto stramit but can be installed onto roof decks such as woodwool, timber, steel beam, concrete etc.

Our dead load system is favoured by many roofing contractors carrying out refurbishment for its ease of use, structural stability, adjustability and competitive price.

All our structures are delivered to site with a full set of detailed laminated drawings and Dibsa assembly guides.

If you have a flat roof that is causing you a headache call Dibsa. We design, we develop, we deliver!

Q – Is a steel lattice beam stronger than a traditional steel beam?

21st January 2014

A – They’re not really stronger as such but they do have a better strength to weight ratio than traditional beams and also allow the passage of services etc.  The lattices can be more efficient and they generally offer better control of deflections.

It’s all to do with the area moment of inertia, for example it’s much easier to bend a ruler in the flat direction than it is to bend it the other way.

The bending strength of the I beam comes from the flanges at the top and bottom but not the web running down the middle, but the web helps increase the area moment of inertia by moving the flanges farther away from the centre of the beam.

A Lattice beam does exactly the same thing really but can be much cheaper and easier to install due to the lattice beam weighing up to 50% less than it’s I beam counterpart.  The deeper the lattice beam (within reason) the stronger it is due to the depth increasing the area moment of inertia.

A traditional steel beam is most appropriately used where the there is limited space available and not enough height available to install the lightweight lattice beam. Although the solid beams have the depth to span advantage they also have a high self weight and often loose out to the lattice beam structures because the open structures provide routes for services to be installed.

Our Dibsa Lattice Beams are generally constructed using either TH45 or TH85 top and bottom booms with an internal web structure made from our SL41 sleeves. These can be made to order to your specific requirements (depth and length), calculations and delivery are available if required, alternatively you can collect from our factory in Barnsley.

If you have a project and you think our Lattice Beams maybe beneficial please do not hesitate to give us a call and we’ll work with you to design the most appropriate beam for your needs.

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