Common Mistakes in Roofing
The installation of metal roofing can prove to be tricky at times, especially with the roof angles in modern home building design. Often the roofing system is broken into several different levels and areas of the entire roof. And, to top it off, the only job acceptable is one that makes the roofing panels as seamless as possible. With all of the various components of the installation process, there are a few common mistakes that novice roofers tend to make like bad panel lapping, improper attachments, excess sealer etc.
1.Bad Panel Lapping
Panel lapping is the process of properly overlaying two metal panels over one another. The correct way to lap metal roof panels is to place the bigger lip (wider lip) beneath the smaller lip (shorter lip) so that the smaller lip lies on top of the wider lip of the previous panel.
In order to prevent future leaks the attachment of the metal panels needs to be done firmly enough to resist high winds, but also gently enough to prevent over-tightening of the screws. You can detect over tightening by looking at the washer that is beneath the head of the screw. If it appears squashed out or compressed and cracking, the screw head is exerting too much force on the washer and its water-proofing capabilities have been permanently compromised.
Screws should always be laid down on the flat portion of the metal panels and directly in the middle of the panel. Be sure to not under tighten the screws either. Washers should be firmly pressed against the metal panel, not loose and free to rotate around the screw shaft.
Contrary to popular belief using an extra thick layer of caulk will not keep water out of your home permanently. In order to properly waterproof your roof, use caulk as a backup water barrier. Your primary water barrier should be the metal panels. Caulk, used properly as a backup water barrier is best used underneath panels, away from direct sunlight and harsh weather conditions.
4.Failing to Meet the Roof’s Edge
Many inexperienced roofing contractors will either take metal panels either too short on the roof’s edge or allow them to overhang the roof edge too far. The best practice methods are to accommodate 1.5 to 2 inch overhang.
Flashing, the metal paneling around roof edges must be attached securely to the roof to prevent water leaks. The areas on a roof most prone to leaks area near ventilation ducts or any areas where there is a penetration into the roof.
In order to get the flashing right around a roof vent, use caulk or sealer underneath the base of the boot that will eventually seal the flashing and the vent. Be sure to use enough screws to properly secure the boot and flashing. Too few screws will result in premature leaks.