Multi-Purpose Sports Hall
Design, fabrication and erection of a 64-metre clear-span hall. A span of this order removes every internal column from the playing area, which is what makes the hall usable for full-size courts.
- 64 m clear span
Structural Steel, Pipe Racks & Truss Systems
Long-span steel roof trusses in Qatar
A long-span truss is a deep steel frame that carries a roof across a wide space with no columns in between. It is used for sports halls, aircraft hangars and other buildings that must stay open inside, as one line of Masas’s structural steel service.
Drawings or a written scope is enough to price it.
Clear spans in the Masas record
Clear span is the distance a roof crosses with no column standing inside. These two figures are column-free spans, not overall building widths. They show the long-span case has been built in Qatar; they are not a reason for your building to need one.
64 m
Clear span, multi-purpose sports hall
Etqan Global Academy: no columns on the playing area
60 m
Clear span, aircraft hangar
The span is set by the aircraft and the door opening
Long-Span Trusses & Clear-Span Structures
What is a long-span truss?
A truss is a frame made of straight steel members joined in triangles. A top member and a bottom member run the full length, with diagonal members zig-zagging between them. Triangles hold their shape under load, so a truss can cross a much wider space than a solid beam of the same weight.
Span has a cost that grows faster than the span itself. A wider roof needs deeper steel to stop it sagging, the steel carries more of its own weight, and the forces reaching the foundations grow. Doubling a span costs considerably more than double.
So a long span is worth paying for when the use cannot tolerate a column: a court marked out to a sports standard, or an aircraft that needs its full width to move. Where a column line can stand along a partition or a rack run, a shorter span is usually the better buy.
Sports halls with full-size courts
Aircraft hangars, where the door governs the frame
Flat roofs over wide open rooms
Roof and wall cladding on the same frame
Plain terms
Terms that matter on a long-span roof
Long-span projects are described with a handful of words. Getting them right avoids paying for the wrong thing.
Clear span
The column-free distance inside, not the overall width of the building. A wide building with columns down the middle has a much smaller clear span, and for many uses it is a different building.
Chords and web
The chords are the top and bottom members of a truss. The web is the diagonal and vertical members between them. The distance between the chords is the truss depth, which grows with the span.
Deflection
How far the middle of a roof sags under load. The design sets a limit on it, because too much sag cracks finishes, disturbs anything hung from the roof and stops water draining.
Drainage falls
The slight slopes built into a roof so rainwater runs to gutters and outlets. On a flat roof over a wide span they have to be designed together with the steel, not added afterwards.
Before you decide
Four questions to settle before the design starts
A long span is the most expensive thing to ask of a steel frame, so each of these deserves an early answer.
The useful question is not how wide a roof can go, but how wide this building must be clear. Fix the court markings, aircraft size or floor layout first, and let the span follow. A span chosen as a round number usually carries steel nobody uses.
Span is only one clear dimension. The height under the lowest steel, and anything hung from it such as lighting or sprinkler pipes, matters too. In a hangar the door opening is so large that it governs the main frame.
Solar panels, air-conditioning units, scoreboards or services all add load across a long span. On a flat roof the steel depth, the sag limit and the drainage slopes have to be settled together before anything is cut.
Long trusses are often too big to transport in one piece, so they are made in sections and joined on site. The space to assemble them, crane positions and temporary bracing during lifting all affect the programme and the price.
How a long-span project runs
The stages are the same as any Masas steel package; the lifting and the roof make them more demanding.
01
Interior fixed, scope written
The use inside is agreed first, then the span and height. Masas confirms in writing what the price covers, including whether roof and wall cladding are included.
02
Design and lifting method approved
Shop drawings, a method statement describing how the trusses will be erected, an inspection and test plan and a risk assessment go to the consultant for approval against QCS 2014.
03
Fabrication in sections
Truss members are cut, welded to AWS standards and protected in the Al Wukair workshop, in pieces sized for transport, and inspected against the approved plan.
04
Lift, brace, clad, close
Trusses are lifted and braced in the agreed sequence, then the roof and walls go on. Snagging, as-built drawings and certificates close the package.
For a quotation
What to send for an accurate quotation
The layout inside
Court markings, the aircraft type, or the floor layout the space must hold. The span and height should come from this, not from a round number.
What the roof will carry
Solar panels, air-conditioning plant, lighting rigs, services or anything else fixed to or hung from the roof steel.
Site access and space
A site plan showing access for long deliveries, and the open ground available for assembling trusses and positioning cranes.
Frame, envelope or both
Whether you need design, fabrication and erection of the steel, and whether the roof and wall cladding are part of the same package.
Record
Where we have delivered this
Contract values are not published. Scale is stated in area and clear span.
An aircraft hangar on a 60-metre clear span
Fabrication and erection of a 60-metre clear-span hangar. The span is set by the aircraft, not by the structure — the door opening governs the primary frame.
- 60 m clear span
Private Residence Flat-Roof Structure
Fabrication and erection of the structural steel for a flat-roof building at a private residence, on a clear span of 18 metres. A flat roof over a clear span carries its own weight the hard way — the depth of the members, the deflection limit and the drainage falls have to be settled together before anything is cut.
- 18 m clear span
More in this service
The other parts of this service, each on its own page with its own evidence.
- Structural Steel FramesStructural steel frames for warehouses, workshops, showrooms and plant buildings in Qatar, detailed, fabricated and erected by one Masas team.
- Pipe Racks & Plant StructuresPipe racks and plant structures for industrial facilities in Qatar, detailed to the plant's own corrosion protection specification.
- Architectural Steelwork & Entrance StructuresExposed architectural steel for hotel entrances and public retail promenades in Qatar, welded and finished to a standard set for close viewing.
- Steel Factory ExtensionsSteel extensions tied into working factories in Qatar and sequenced around production, including an aluminium extrusion plant and a battery factory.
Common questions
- What is the difference between clear span and building width?
- Clear span is the distance inside with no column in the way; width is the overall size of the building. A wide building can still have a line of columns in the middle. When asking Masas for a price, state the clear span the use needs.
- What is the longest clear span Masas has built?
- Masas designed, fabricated and erected a multi-purpose sports hall for Etqan Global Academy on a 64-metre clear span, which removes every internal column from the playing area. The Masas record also includes an aircraft hangar on a 60-metre clear span.
- Does a longer span cost proportionally more?
- No, it costs more than proportionally. As a span grows, the steel gets deeper to limit sagging, carries more of its own weight, and puts larger forces on the foundations. Masas recommends fixing the interior layout first and designing the smallest span that serves it.
- Can Masas supply the roof and walls on a long-span frame?
- Yes. Roofing and cladding systems are in Masas’s ISO-certified scope alongside structural steel, and the Masas record includes the envelope on the 64-metre sports hall and the 60-metre hangar. Frame and envelope under one subcontract removes the gap in responsibility where cladding fixes to steel.
- Does Masas build long-span flat roofs as well as pitched ones?
- Yes. Masas fabricated and erected the steel for a flat-roof building at a private residence in Rawdat Al Hamama for Contraco, on an 18-metre clear span. On a flat roof the steel depth, the sag limit and the drainage slopes are settled together before fabrication.
Need a quotation for this?
Send drawings or a scope and we will come back with a quotation.