Roof Rafter Spread

Therefore the first signs of roof spread are often cracking bulging or leaning at the head of the masonry causing bowed walls.

Roof rafter spread.

This ties them together and prevents any outward movement. Please follow and recommend our blog page. 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. So fixing the problem as soon as possible is vital.

Roof rafter decking sagging. Factors that cause the situation include bad construction improper materials and water and rot problems. 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. Split ridge board causing rafter instability and subsequent applied horizontal thrust to the wall plates.

It also leaves a void the loft which can be used for storage or the placing of water tanks etc. This is referred to as roof spread. Roof spread affects a roof that begins to move after it is installed. N modern cut timber roofs pre 1970 constructed on site this force is normally resisted by joining the bottom of each pair of rafters see fig.

Roof spread occurs when the principal rafters of the roof are not adequately supported causing them to open in a scissor like pattern. Roof spread can be dangerous for a house and very damaging for a roof. This article describes a diy repair project using a site built spreader to straighten sagged roof rafters and decking. If looking for the obvious and common cause of roof spread then this particular issue could so easily have been missed especially when limited to a head and shoulders inspection from the loft hatch.