Related Roof Components

Skylights

Skylights should be inspected from both the roofing side and the interior of the home. Items to look at on the outside of the roof are:

(1)  Skylights should have adequate curbs, whether they are manufactured units or not. Skylights without curbs or with inadequate curbs do not allow for proper step and counter flashings, and are destined to leak. Some adhesives/sealants are better than others, however, without proper flashings, the skylight seal would not be considered dependable and the installation of proper flashings should be anticipated.

The skylight curb height on a sloped roof should be approximately 4 inches, for a flat roof; it should be 6 to 12 inches, depending on the potential for snow in the geographical area.

(2)  The flashing detail around skylights, particularly those installed after the original construction, is frequently improper. The most common problems are improper or non-existent step and counter flashings, lack of adequate curbs and failed thermal seals.

Solar panels

Solar panels mounted on a roof are beyond the scope of a general home inspection. However, they are frequently defective, and responsible inspectors will be aware of the potential problems. The major problems with solar panels:

(1) Areas where they are fastened to the roof are typically tarred over with roof cement and will eventually open up and leak.

(2) The framing (i.e., truss/rafter) beneath the solar panel may not have been reinforced to receive the areas that bear on the roof or to accommodate the additional weight.

(3) Leaks are relatively common. In many cases, these panels have outlived their usefulness and have been abandoned in lieu of repairs or updating.

Antennas

Antennas secured to a roof or chimney are vulnerable and may cause problems. Installers and homeowners have been known to anchor to the chimney, roof and/or home structure with guy wires that may be stressed during high winds. Over time, these wires create stress points at the fasteners, which become loose and weak.

Chimneys above the roof

While on the roof, evaluate the chimneys above the roofline. The masonry chimneys may have multiple flues. If the chimney is only one brick or 4 inches thick, and without a liner, it is defective. To be safe, a one brick chimney must have a flue liner all the way to the firebox on the bottom. A chimney two bricks or 8 inches thick does not require a liner. Cracked mortar, spalling bricks, or cracked caps are very common defects.

The reason chimneys deteriorate at the top most quickly is because they heat up, then cool off in the colder months, in rapid succession, causing the bricks to crack, and allowing condensing water to penetrate. The penetrating water can then cause deterioration, or even worse, freeze, then expand and causing larger cracks. When possible, look down the chimney to ensure that the terra cotta liner or the brick is in good condition. Metal chimney flues, normally for gas or oil-fired heating plants, should also be inspected above the roofline. These metal units should have a weather cap installed on them, and should not be rusted out. The individual sections should be screwed together.

Large metal pans that are installed at the top of some metal chimney structures should be convex to assure proper shedding of water. In some situations, the metal chimney is hung from this pan, causing it to distort and become concave. There is a collar in the pan that goes around and is screwed to the metal chimney. This collar may likely keep the pan from leaking for 10 years or more. However, it may eventually fail, and all of the water that lands on the pan will fall into the chimney structure. Check the top of metal chimneys. If you are unable, inspect the area around and adjacent to the chimney for even remote water stains.

Overhanging trees

Overhanging trees or brushing on a roof are not a defect unless they are actually causing damage. If leaves are lying on the roof, they may be causing moisture damage to the roof sheathing. This typically will not be visible, so check the ceiling below the area that the leaves are located for even the most minor stain, and carefully try to walk the roof in the area that the leaves are located. If the house is older and it appears that the leaves lay in one area for months at a time, it is possible to have severely weakened sheathing. If shingle granules are worn off, it is suggested that the tree be cut back and the roof be repaired, if necessary.