Roof Spread Repair

The collar ties are used in a similar way.

Roof spread repair.

Tar the roof keep your tar bucket close to you as you start spreading the tar on the surface with the roller. Roof rafter decking sagging. This article describes a diy repair project using a site built spreader to straighten sagged roof rafters and decking. Collar ties and tie beams are both construction fixes that can be installed in a roof frame to help stop or solve roof spread issues.

Roof spread occurs when there is a failure to adequately support the main rafters of the roof so as to prevent them spreading further open in a scissor type action. Roof flashing cement is a dense or thick sealant paste applied by trowel or from a tube used to seal small cracks holes gaps or at intersections of flashing or roofing and other building surfaces. This is a prolonged process but can cause severe damage to the integrity of a home. Roof spread occurs when the downward pressure of the weight of the roof starts pushing against the rafters enough that the structure itself begins to move.

When considering what to do about sags in a roof start by noticing if the sag is in sheathing between rafters page top photo0 or sagging along the length of the rafters. Either the roof starts moving downwards or the walls start pushing outwards. Since the rafters are fixed to timber wall plates sitting on the head of the masonry wall then roof spread pushed out those wall plates in the process pushing out the masonry below. It has roof spread and to remedy it will mean a major expense possibly even taking the roof off.

The problem of resisting roof spread is a real one and it is always worth checking how roof spread is resisted when carrying out repairs or modifications to a timber framed structure. Spreading roof structures turning our attention to roof structures spreading out of the a frame is often indicative of inadequate ties or decay at eaves level. Roof spread is often caused by the roof timbers being subjected to extra weight weight that they were not designed for. With roof spread the ceiling joists normally act as collars restraining the rafters from pushing the walls outwards so new collars may need to be installed or tie rods inserted through the upper walls.

The tie beams are fixed to the rafters horizontally to stop them from spreading. This will ensure that any repairs or modifications undertaken will not harm the existing structure. Inserting additional often lower collars tie beams between the trusses or rafters assists greatly in reducing roof spread and this consequently restrains the outward thrust on walls. As you work you will move back toward the end where your ladder is taking the bucket with you.

Rotten timbers can be cut out and new timbers spliced alongside or bolted with metal plates.