OZCO 51717 Ironwood 2-inch Rafter Clips, (10 per Pack), Black

Product Information

A truss clip should always be fitted vertically to a wall plate, never lying flat or horizontally. You must make use of every hole on the face of the roof truss clip, and nail all of these in. Some installers may only use four of the thirteen holes which are on the clip – this is not utilising the strength of the clip fully. Where straps are fixed to masonry, hardened nails 4mm in diameter x 75mm long or No 12 wood screws x 50mm long into plugs should be used. Where half-round tiles are used at hips, they should be supported at the base of the hip by a galvanized hip iron. (d) valleys and hidden gutters

Provides support to purlins to prevent deflection and to transfer roof loads to the load-bearing structure below. If the design specifies holding down straps to prevent the roof being lifted off the supporting structure, they should be at 2.0m centres (maximum). STRUTS: give support to purlins to prevent deflection and transmit roof loading to loadbearing structure below.For cold roofs that incorporate a low water vapour resistance (type LR) underlay, (e.g. a vapour permeable underlay) ridge or high level ventilation equivalent to a continuous opening of 5mm should be provided in accordance with the design. (b) underlays A strip of underlay, at least 600mm wide, should be laid over hips and above the underlay to the main roof. Where cheek framing does not extend to floor level, a double rafter will give necessary support to the cheek. The two rafters must be fixed together.

The guidance above will assist in reducing the risk of condensation occurring but is not acceptable as an alternative to cross ventilation of the roof space.

Sin No 5 Poor site handling and storage

Notes for surveyors / building control officers. Properties built during the 1960s and 1970s frequently do not have diagonal bracing and all of the necessary longitudinal bracing. Even if the roof shows no signs of any deformation it is important that such bracing is added retrospectively. When using the following materials, the detailing and workmanship should follow the design and recognised good building practice: All members should be accurately located. Purlins and binders should be built in, where necessary. In a typical traditional roof, the basic timber members are: RAFTERS to ceiling joists: nailed lapped joint. The rafter should be birdsmouthed over and skew nailed to the wall plate

Cavity trays should be linked to the flashing to prevent water penetrating into an enclosed area where a: The design should specify the number of fixings for clay and concrete tiles. Tables 2 and 3 of Appendix 7.2-B contain minimum fixings for tiles. Additional nails and clips may be necessary in accordance with the design. A fixing schedule produced by the tile manufacturer, based on The Zonal Method, is acceptable. If you are securing more than one roof truss, then you will need to use framing anchors. This is because roof truss clips are limited to being 38 or 50mm. If dealing with a set of two, three, or 4 trusses, then framing anchors can go either side of the truss at either end of the wall plate. Framing anchors, similarly to truss clips, provide a secure fixing.All verge tiles and slates should be bedded on an undercloak. Alternatively, proprietary dry verge systems should be fixed in accordance with manufacturers' recommendations. Where roof coverings are of plain tiles or slates, laced and swept valleys may be used or, alternatively, a mitred valley with soakers. Where proprietary eaves ventilators are used, they should be fixed in accordance with the manufacturer's instructions. The underlay should be turned up at least 100mm at all abutments to prevent rain and snow being blown into the roof space.

Dormers should be framed up so they are independent of the window frame, using a suitable lintel over the opening.Roof truss clips are metal components that are designed to safely and strongly fit roof trusses to wall plates. This resists wind uplift on the roof truss which avoids any damage by skew nailing. Battens on rigid sarking boards should be supported on counter battens to allow free drainage of any water that may reach the underlay. Counter battens should be fixed through to the rafters and not to the sarking boards alone. Battens should be fixed through counter battens to rafters.