To maintain stability, our floor trusses need to be braced all the way through their supporting structure. All wall supports and the ends of the trusses should have timber braces or a Pryda Strapbrace inserted diagonally. All timber braces used this way should be at least 25 mm thick, at minimum. There is an alternative, however. Placed at the end of each truss can be a continuous trimming beam, and only the end bays will need diagonal bracing.
All Pryda floor trusses are to be braced entirely through their support structure. This creates the necessary stability. In order to accomplish this, you should use timber braces that are at least 25 mm thick or Pryda Strapbraces. These should be inserted diagonally and placed at the trusses’ ends as well as at all the internal wall supports. Another way to provide the necessary support is to place a continuous running beam at the truss ends. If this method is used, then only diagonal bracing at the end bays needs to be added.
All Pryda floor trusses also have to be braced to provide the necessary support. These trusses are to be braced all the way back to the support structure. When bracing in this manner, you should use a Pryda Strapbrace or a timber brace that is at least 25 mm thick. These should be diagonally placed and will need to be put at all internal wall supports and the truss ends. If desirable, a continuous trimming beam may be used instead. This would need to be placed at the end of the trusses and only the end bays would need diagonal bracing.
All the trusses are to be fastened to the supporting plates by at least 2 nails that are 75×3.15mm in diameter. It is advisable to use Pryda Minigrips and fasten them in with 3 35×3.15mm nails for a better fixing.
Each truss shall be held onto its supporting plate/bearer by a minimum of 2/75×3.15mm dia. Nails. If preferred, a better fixing may be achieved by using one Pryda Minigrip with 3/35 x 3.15 mm dia. Pryda nails per tab.
If the trusses are being supported by timber beams or steel with top chords, then the bottom chords need to be restrained with skew nails. In addition, a support beam with either Pryda Multigrips or screws should be used to fix the top chord. This reduces movement and vibration along the supports, making for a stiffer floor.
To improve the stiffness of the floor (by decreasing the amount of vibration or movements in the supports), all bottom chords should be restrained with skew nails. The top chord would also need to be fixed, which can be accomplished with Pryda Multigrips or screws. This applies to all instances where the timber or steel beams are being supported by the top chords.
If the wall is positioned between two floor trusses and is a wind bracing element with a capacity of no more than 1.5kN/m and does not exceed 2.7m high, fix noggings at each end of the bracing element to transfer wind forces to the adjacent trusses. Use 2/14gx100mm Timberfixx drilling screws to fix the bottom plate of the bracing element into the nogging, and 12gx65mm Timberfixx screws to fix the bottom plate to the flooring at 450mm centres along the length of the bracing element. For wind bracing wall capacities of up to 3.0kN/m fix a 120×45 MGP10 strongback to the vertical web nearest the end of the bracing element. The strongback will pass through two trusses either side of the wall and fix to the webs with 2/12gx65mm Timberfixx screws. The flooring material shall be nailed and glued to all floor trusses in the flooring system.If a bracing wall sits directly over a floor truss then fix 14gx100mm Timberfixx screws into the truss at 450mm centres along the length of the bracing element along with 2/14g x 100mm screws at each end for 1.5kN/m wind bracing capacities. Use 4 screws at each end with the strongback detail as outlined above for up to 3.0kN/m wind bracing capacities.
For wind bracing walls of up to 1.5kN/m wind bracing capacity with the element no higher than 2.7m, use 14gx100mm Timberfixx screws to fix the bottom plate of the bracing element to each perpendicular floor truss. If the end of the bracing element finishes directly above a floor truss use 2/14gx100mm Timberfixx screws, and if not then use the same screws into the nogging as previously mentioned. For wind bracing walls of up to 3.0kN/m capacity adopt the same details as for bracing walls parallel to the floor trusses. The flooring material shall be nailed and glued to all floor trusses in the flooring system.
All supporting structures should have the Pryda trusses affixed to them. You should only use connections that meet or exceed specifications for the force of wind uplift on each truss. You will need to fasten the trusses to their supporting plates or bearers with at least two of the 75×3.15mm skew nails. You can also use three 35×3.15mm nails on Multigrips or Minigrips, if you like. A Pryda Strap should also be used to brace trusses laterally at the ends.