proper spacing between rafters for metal roof

PROPER SPACING BETWEEN RAFTERS FOR METAL ROOF HOW TO
PROPER SPACING BETWEEN RAFTERS FOR METAL ROOF INSTALL

Remove the blocking as the sheathing is installed.

Until the diagonal bracing is installed, the whole truss set can simply rack over like a line of dominoes.

An unsheathed roof is similar, with much more dire consequences.

2×6 rafters are stronger and can span longer distances than 2×4 rafters. Should I use 2×4 or 2×6 for rafters The choice between 2×4 and 2×6 rafters depends on the load requirements for the roof. When positioned, roof purlins should be spaced no further than 1.2 metres apart when using sheeting with a thickness of 0.7mm, and 1 metre when using 0.5mm. For spacings up to 600mm, a 50 x 25mm batten section is advised. The spacing of roof rafters is typically 16 inches to 24 inches on center, depending on the local building code and the design of the roof. Purlins can be placed on edge, using engineered steel joist hangers, between each set of trusses and spaced every two feet to support your sheathing. On top of the roof sheathing you tack down tarpaper or roof felt. For single lap tiles on rafters with a 450mm spacing, battens should measure 38 x 25mm. Roof sheathing gets little metal spacers to help you with the proper spacing.

Consulting with your timber supplier can offer additional insights. Select timber species as per the standards laid out in BS 5534. During assembly, the horizontal shelves will support the spacing between the vertical walls of the shelf, but until the back panel is installed, the shelf will be unstable – subject to twisting and racking. This measurement will dictate the spacing between your battens. Lateral bracing alone is not adequate to secure roof trusses before sheathing.

PROPER SPACING BETWEEN RAFTERS FOR METAL ROOF INSTALL

Install diagonal bracing, representing a “W” pattern throughout the structure (See red blocking in Diagram 1).Nail the bracing into the top chord of each truss, making sure to follow the truss manufacturer’s layout while setting trusses.Alternatively, blocks can be cut to 22½” and inserted into the spaces between the top chords of each truss, instead of on top of each truss.This puts the blocks at risk of splitting during installation. Often builders fail to extend their blocks beyond the end of each truss, cutting them to only 25½”.When spaced at a typical 24” on center, this means cutting blocks to at least 27” in length. Each end of the block should extend at least ¾” beyond the outside edge of each truss. Precut blocks of 2×4 lumber to span from the top chord of one truss to the top chord of the next (See green blocking in Diagram 1).

PROPER SPACING BETWEEN RAFTERS FOR METAL ROOF HOW TO

How to Install Traditional Lumber Bracing: One of the most common methods for bracing roof trusses is using 2×4 blocks of lumber to provide temporary support before the sheathing is installed

Proper spacing between rafters for metal roof