Attic Conversion Truss Roof

Step 1 measure the width of your roof trusses from inside to inside.

Attic conversion truss roof. This process involves the installation and use of steel beams. Measure in from the lower edge of the roof to a point 1 4 the width of the truss on either side of the attic. It s a 12 12 roof so that s a good 11 at the ridge which even with new floor joists and a 5 knee wall should be plenty of room for a nice space. The sad fact is your builder could have installed attic trusses over this garage for just slightly more than what the existing trusses cost.

The conversion from a trussed roof to a trussless roof simply involves the redistribution of the roofs weight from the trusses to beams running from gable to gable. Ironically though it s the rafters that provide a better environment for an attic conversion because of the clear space. Trusses are considered a superior method of framing a roof because of the additional support. Most roofs built from the late 1960s onwards are of prefabricated trussed rafter construction with distinctive w shaped webbing.

Added rafters and floor beams strengthen the current loft structure creating an open larger living area. The trusses are double cantilever style. Before work can begin a structural engineer will calculate the size of the steels required. If you have trusses it will be next to impossible to reconfigure them to allow for clear space.

Use a chalk line to draw a line along the floor parallel to the lower edge of the roof from one end of the attic to the other on both sides. Although once regarded as hard to convert on account of their relatively slender roof timbers typically only about 30 x 70mm many lofts of this type have been successfully converted. The role of the horizontal beam is to tie the truss together and carry the load that would otherwise be sustained by the support and vertical timber also known as the king post. Attic conversions are now possible by replacing the truss rafters with a shaped trusses or horizontal beams which in return create additional space.

Looking back i was very lucky in that my roof had an unusually high 47 degree pitch and so there was lots of head room. Converting a trussed roof is now commonplace. The w shaped trusses are replaced with a shaped trusses or horizontal beams. The attic space is 22 on the side parallel to the trusses 28 on the other side.