Roof repairs near Blackburn, Lancashire.
We were sent the following photograph of a six metre wide, softwood roof truss in a historic barn in Rossendale, Lancashire. The building was undergoing renovations and had already been re-rooved. Ideally the truss should have been replaced before the roof was put on, so this job was made all the more difficult.
A cleat had been fitted to extend the king post to meet the new ridge line, and the rafters were supported with bricks.
We propped up the roof under the ridge and purlins with six steel Acrow supports and then tightened each to lift the entire roof a fraction of an inch, taking the weight off the truss and allowing the work to begin. The brisk supports were removed.
The softwood rafters were bolted together, so these bolts were removed with an angle-grinder and the rafters were pulled out of position and lowered to the floor.
Housings were cut into the main 6 metre beam with a chainsaw, one in the middle to seat the new king post, one at either end to bear the load of the rafters, and two in between to house the struts provide additional support to the purlins. A template was made to accurately gauge the sizes required for the component parts of the new truss.
The marks were transferred from the template to the new oak rafters and post, with axe and chisel.
The new oak rafters and post were fitted snugly in position, and the props were removed.