Timber Roof Wall Plate Size

Wall plates should be joined using half lapped joints at corners and in running lengths.

Timber roof wall plate size.

The trimmed joist will measure 600mm minus the thickness of the joist substitute 600 for 400 450 or whatever centers you are working to. A plate in timber framing is a piece of timber upon which some considerable weight is framed hence ground plate window plate obsolete etc. Generally wall plates are in lengths of not less than 3 m. Also called a wall plate raising plate or top plate an exception to the use of the term plate for a large load bearing timber in a wall is the bressummer a timber supporting a wall over a wall opening see also.

These are typically 1 2 m long with a cranked end and are fixed to the wall plate at 2 m centres. The roof covering membrane may also require additional fixing using mechanical fasteners to prevent uplift high wind load areas. If you have tall joists you may need to cut a splice or seat cut on the end of the joist so it doesn t protrude above the rafters. Likewise for the trimmed joist 600mm from the outside of the wall plate.

As the mortar does not bond the wall plate to the wall steel straps are used to ensure that the roof structure remains secure. Fixings used to connect the roof structure to the wall plate should be specified according to the roof construction and exposure of the site. Where trussed rafter roofs are not subject to uplift a minimum of two 4 5mm x 100mm galvanized round wire nails skew nailed one on each side of the trussed rafter or truss clips fixed in accordance with the manufacturer s instructions are acceptable. Minimum timber size will be 95mm x 35mm although this may increase for the following reasons.

Wall plates should generally be in lengths of not less than 3m but shorter lengths should extend over at least 3 joists rafters or trusses. 38 x 100mm or in accordance with local practice.