Finish with weberend MT system with choice of finishes. the timber frame, including any roof construction supported by the timber frame. Separating wall junctions 1.4. Appropriate measures should be taken to prevent buckling. The superstructure design should be placed with an NHBC approved timber frame certifier so that a certificate can be issued in accordance with Appendix 6.2-A. Joints in head binders should occur over a stud. staircases and lift shaft enclosures (where they are not timber framed). Vertical timber cavity barriers should be protected from penetrating moisture by a dpc. TIMBER FRAME STANDARD DETAILS SEPTEMBER 09 Building 1 Grosvenor Court, Hipley Street OLD WOKING, SURREY Tel: +44 (0) 1483 769518 Fax: +44 (0) 1483 770863 E-mail: Internet: . In Scotland, Northern Ireland, the Isle of Man and other places where the exposure to driving rain is Severe or Very Severe, masonry should form a rebate at the reveals of openings to avoid a straight through joint where the frame abuts the masonry. A drained and vented cavity should be provided to reduce the risk of rain penetrating to the frame. The design should take into account: Sheathing and its associated fixings should be structurally adequate to resist racking due to wind and other forces. Design shall meet the Technical Requirements, Design shall comply with all relevant statutory requirements, Loadbearing timber framed walls shall be designed to support and transfer loads to foundations safely and without undue movement, The design shall ensure that the structure is adequately protected from the effects of moisture, Timber and timber products shall either be naturally durable or where necessary be treated with preservative to give adequate resistance against decay and insect attack, Exterior cladding shall be compatible with the timber frame. Timber constructions often rely on a vapour barrier on the warm internal face. movement between the timber frame wall and other elements. In areas of Very Severe exposure to wind driven rain (as defined in Appendix 6.1-A) a high performance breather membrane should be used (unless the alternatives given in Clause D4(c) below are adopted). Provide suitable sheathing board spaced off the insulation/stud to maintain the drained and ventilated cavity. The anticipated amount of shrinkage of the timber frame is given in Appendix 6.2-C. Movement between the timber frame and other parts of the construction will occur at: Appendix 6.2-C provides guidance on the anticipated amount of shrinkage of the timber frame and where it will occur between other parts of the structure. This Chapter applies to timber framed walls up to seven storeys high. Fix suitable sheathing board spaced off to create drained/ventilated cavity and finish with weberend MT. I-studs manufactured from timber of durability class 'moderately durable' or lower should be preservative treated in accordance with Chapter 2.3 'Timber preservation (natural solid timber)'. inclined away from the sheathing so that the slope is maintained following differential movement. The vapour control layer should cover the external wall including bottom rails, head rails, studs, lintels and window reveals. The tray should have a minimum upstand of 100mm. This Chapter gives guidance on meeting the Technical Requirements and recommendations for external walls of timber framed dwellings, substantially timber framed dwellings and wall panels (including relevant certification procedures). For guidance on the prevention of fire during construction see 'Fire prevention on construction sites' jointly published by the Construction Confederation and the Fire Protection Association ( Insulated sheathing boards should be assessed in accordance with Technical Requirement R3 and installed in accordance with the assessment. All joints in sheet vapour control layers should have at least 100mm laps and be located on studs or noggings and be adequately fixed to the frame. Timber constructions often rely on a vapour barrier on the warm internal face. Timber cladding should be treated in accordance with the guidance in Chapter 2.3 'Timber preservation (natural solid timber)'. Note: Due to space constraints, full specification details for panel based systems are not included in this guide. This diagram shows a masonry external wall tied back to a timber frame structure using cavity wall ties.