Residential Roof Systems Cause Sagging

Your home’s roof lines should be perfectly straight. If you notice any curve, dip or swag, there is a problem with your roof. In some instances, you can deal with the issue on your own, but you will probably need to have it fixed by The Woodlands roof repair professionals at Paramount roofing.

The easiest way to learn about your roof’s structural makeup is to visit your attic. You will see that your roof line is a basic triangle. As you stand in your attic, the boards beneath you are the ceiling joists. The rafters are the sloped boards above your head. At the very top, a separate beam, called the ridge line, is attached to the rafters. Those three elements complete the triangular shape of your roof, which can support the weight of the shingles and roof sheathing. The joists absorb the weight from the rafters. The exterior walls absorb the load from the joists. If your roof is in good shape, the roof line will be nice and straight.

The horizontal rafters of the ceiling can be the cause of a sagging roof line. Two of the rafters are frequently lapped and nailed together to accommodate the required length. The weight of the roof and external forces can push down on the roof, which forces the rafters outward. Then, the rafters exert pressure on both sides of the exterior walls. If the joints were butted together instead of being lapped, the stress can make them detach causing roof support problems. Even joints that have been properly lapped by The Woodlands roofing company technicians can suffer from excess weight. If the joint separates, the ridge line will droop because the exterior walls have become tilted. You may not notice it from the outside, but you probably can when you are inside your attic. Cracks in the ceiling’s drywall are another indication of roof sag.

Using a central beam instead of lapped ceiling joists is another type of roof framing. With this method, two beams are attached to a larger beam that is perpendicular to the joists. The joists are fastened to the two sides of the beam with metal hangers. Pressure from the roof’s weight can cause the hangers to pull loose, which makes the exterior walls sway to the outside. This causes the roof line to sag at the top.

On occasion, rafter collars or ties might be added to the sloping rafters. They fasten the two rafters on both sides. The collars are usually attached halfway up the rafters. The purpose is to keep the rafters from bowing away from one another. The rafter ties must be placed properly. If not, the rafters could still spread. If the ties are not nailed correctly to the rafters, the nails can become detached, which lets the rafters bow.

Sometimes, a perpendicular strut or beam is placed across the base of the rafters. That beam is fastened to the exterior walls and to the bottom of each sloping rafter to strengthen the roof. The beam can pull loose if it is not nailed in place correctly, which will cause roof sag. If the strut is not the right size or if it has a split or crack, roof line sagging might occur.

Sheathing that is saturated or rotten can cause a roof to sag. Soaked sheathing can warp, which makes the roof appear to be sagging.

Paramount Roofing specializes in The Woodlands roof replacement and repair. Their experienced technicians can examine your roof and let you know what is wrong and what it will take to make it right. Call 713-748-4000 to schedule a free estimate if you see that your roof is sagging.