A roof truss is a type of built-up structural member that can be used in place of a single girder or beam. Trusses are made from multiple straight members (generally made from wood or metal) arranged in triangles. This design allows a truss to span a very long distance without intermediate support; they are preferable to large, heavy girders because of their low cost and easy implementation.
A Fink Roof Truss showing Top Chords, Bottom Chords and Webs.
The design software at Minera Roof Trusses enables us to design projects ranging from the very small to the very large which can incorporate multiple types of roof trusses with varying spans and truss shape configurations.
The best material for building trusses is stress graded TR26 grade timber which is exclusive to the Trussed Rafter Industry.
Your roof truss will need to be able to handle the expected dead loads and live loads of your structure's roof. Your roof truss will also need to be supported adequately at its ends, its bearing points.
The roof truss will have a horizontal lower chord (bottom chord / tie) and 2 angled upper chords (top chord) that follow the roof line in a duo shaped roof structure. These chords, the top and the bottom will be connected by "web" members, which will be oriented to form triangles. Triangulation provides the basis for the strongest possible structure for supporting weight.
Once Minera Roof Trusses have designed your roof truss to British Standards and/or European Standards, we saw each member to its required length. We also provide the correct angles on each end and mark up each member so that the shape of the required truss can be fitted together on our pressing tables.
Here at Minera Roof Trusses we have invested in the top of the range, state of the art machinery, which allows us to be geared up for very high volumes of timbers that need to be cut and because we operate the only 5 day delivery nationwide ALL YEAR around, we have to be precise and be very efficient at our job.
Our Depauw Saw 16 axis 4 blade computerised saw.
Our experienced sawyers team make sure that our timbers are cut to the exact length that our production managers instruct them to produce. After marked and stacked, the timber is then moved onto the pressing department.
The pressing process is a very very important stage in the manufacture of a roof truss. All these cut pieces of timber will now need to be fitted together and have metal connector plates fitted to that on both sides. Many people have the perception that the metal plate that connects all the pieces of timber together can be simply "hammered in" on site.
This is NOT the case. Each plate is designed by the engineer to take into account the deflection in each joint, the moment in each joint and have to take into account whether the member will be in compression or in tension. Each member will contribute forces into each joint. It is critical that each plate takes all this into account in all load cases, for example, your roof loaded with tiles, snow, tanks, plasterboard, light storage and for the person standing in the roof.
Our pressing team having setup the pressing tables to the information provided by the production managers, will position the metal plate connectors over each joint. AGAIN, these are NOT hammered in.
Truss pressing table with timbers slotted together with metal connector plates over each joint and the press in action.
Minera Roof Trusses use a gantry system in the optimum position for producing our vast quantities of roof trusses. It is a hydraulic press and it is repeatedly exposed to tremendous pressure. For this reason, our hydraulic presses are extremely robust. The maximum press power is between 23 and 50 tons. As you can see, this is a lot different to many peoples believe that the plates can be "hammered in". Hammering is disproved by British Standards because its damages the galvanising on the metal teeth and the teeth also roll. Pressing stops this as the plate enters the timber in one swift movement.
A 23 - 50 Ton press used to press the metal connector plates into each joint of the trussed rafter.
This procedure is then repeated on the next trussed rafter until the quantity required is reached. Then, we start again with the next truss configuration.