Roof maintenance is critical. If your roof starts leaking, it may cause damage to your attic (could be unnoticed for years), air quality because of mold or mildew, sheetrock damage, damage to furniture and so on. The cheapest way to maintain your roof is to keep it clear of debris, free from moss and maintain or replace roofing material. Roofing material is the least inexpensive maintenance water damage to your house.
The roof is a critical first defense of a house against weathering. The roof is an "inexpensive" material that absorbs the brunt of weathering from: sun, rain, wind to protect the interior structure and finish materials on the inside of the house. Insulation, wood and sheetrock in walls would not stand up long against water, sun and wind. Roofing is sacrificial and not designed to last forever. Once it has been damaged too much, it is covered with more roofing or removed and replaced.
Before you know how to inspect a roof, the roofing material must be identified. There are several types of roofing materials, the most common being asphalt.
Among asphalt roofs, there are 3 tab(most common), laminate, architectural, rolled roofing.
3 tab roofing is a single sheet about 3 feet wide with 2 vertical notches cut out equidistante from each other. This results in "3 tabs" being created after the 2 notches are removed. The 3 tabs go downstream (lower side) and the roofing material is fastened within a few inches above the tabs to the roof sheathing. The notches give some detail to the roof so it doesn't look so blank. Roofing nails with large heads are used to secure the 3 tab to the plywood sheating below. Some people use staples (not recommended) which voids many roofing warranties (read warranty that comes with shingles). Roofing is installed from the bottom row and working your way up the roof (as you offset each row) so that it sheds water and fasteners are covered with roofing material. See also 3 tab roofing
Laminate shingles are a solid sheet of ashpalt materia about 3 feet wide and instead of notches , they laminate more pieces of asphalt material onto the lower half of the shingle. This created more texture and detail to simulate cedar shake roofs. While laminated roofs look more detailed and fancier than 3 tab roofs (laminate roofs have replaced many 3 tab shingled roofs), the increated texture and surface areas have created more areas for tree debris to lodge, dirt to accumulate, moisture to be trapped and algae and moss to grow. It is more critical to keep up on inspections with a laminate roof than a 3-tab roof because mainteance needs are higher.
Architecural shingles are solid sheets of asphalt that are very thick and as a result, much more ridged. They are like laminate shingles, but everything is thicker. The laminated pieces are thicker. This creates shadows and eddies in air and water flow that provide for even more areas for dirt, dust, debris and the resulting algae and moss. Architectural shingles are made thicker to look more like cedar shake roofs and it's resulting cost (besides increased initial shingle expense and higher installation costs) is the increased mainteance. Architectural shingles are the highest mainteance of roofs.
A common error in roofing is to overdrive or underdrive the nails which either creates holes (overdriving the nail), or bumps (underdriving the nail).
The roof requires some mainteance from homeowners so it can do its job with longevity. The roof needs to be kept free of debris that would slow the water from running off the roof. The flatter the roof, the more important it it so keep the roof clear of debris. Things that cause roof leaks include: punctures by fallen branches, leaves and needles that trap water and moss which grows on the bottom edges of shingles. Also, the sun beating on the roof will eventually cause the tar in the shingle to dry out and crack, letting water through. For concrete tile roofs, the ultraviolet rays will destroy the finish on the concrete tile, cracking the outer finish and allowing the concrete in the tile to absorb water and slowly feed it out to algae and moss.
See also Roof Moss Treatment or Killing Moss
See also Roof Cleaning or Cleaning Algae off your roof
See also Roof Moss Removal or Scraping Off Moss