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What are the longest beams DESSA offers?

We can manufacture beams of any length to suit any application. From stock, on the basis of satisfying ease of handling and weight, we manufacture to the following lengths for our beam series:

• 45cm alloy – up to 8.1m.
• Asterix 75cm / D78 – up to 6m.
• Asterix HD 133cm – up to 4m.

For non-stock lengths, please use our online form or contact info@altrad-dessa.com.

Why has my roof failed on EstAssist?

The EstAssist checks are not comprehensive and make a number of worst case assumptions. EstAssist is not a design package and all temporary roofs should be designed and validated by a competent design Engineer. We operate a contract design service to all our clients, contact us for further information at engineering@altrad-dessa.com

Do you have a guide for EstAssist?

EstAssist has a User Guide built into the software which can be accessed using the Help menu.

How can I get EstAssist?

To obtain EstAssist please request using our online form or contact info@altrad-dessa.com.

What is a tie bar, why might I need one?

A tie bar is a systemised set of tubular elements that provide a connection between the bottom chords of roof trusses on a duo-pitch roof span. This system prevents the roof from spreading under large downward loads. When laced effectively, it also provides additional resistance against uplift forces. It may be considered for projects requiring a large span, projects subject to heavy snow loads or downward wind loads, or projects with limited tying possibilities.

What is the biggest span achievable?

This is very much subject to a variety of factors, including but not limited to:
• Location
• Environmental loads.
• Duration of project.
• Bay size.
• Support structure.

In moderate climate and exposure the following maximum spans can be expected:
• 450 series – in excess of 20m.
• 750/780 series – in excess of 30m.
• Asterix HD – in excess of 50m.

Why does my monopitch roof need to be at a 15 degree pitch?

A 15 degree inclination allows water to run off the roof without excessive water depot build up, avoiding water ponding and ingress in to the sheet tracking. Use of DeepFlow™ tracking allows for roof pitches to be made shallower and has been proven on spans pitched at 10 degrees.

What is the weight of UNI Roof/AHD as a system?

Based on 2.5m bays UNI Roof is 8-10kg/m2 and Asterix HD is 13-15kg/m2.

Can my tie bar be laced in scaffold tube to enable compressive and tensile capacity?

Yes. A quicker alternative is to use DESSA bracing elements.

How high can my UNI shelter go before I need to consider a vertical beam?

It is recommended that no taller than a 2.5m standard should be used on a UNI shelter.