Roofing Components

Although a roof is, overall, basic in its form and function, it is comprised of several various components.
Regardless of Design or the Type of building they top, all roofing systems have five basic components:

  • Structure: The rafters and trusses that support the decking.
  • Decking/sheathing: The boards or sheet materials that are fastened to the roof rafters to cover the house. Underlayment: Sheets of asphalt-saturated material. Used as a second layer of protection for the roof decking.
  • Roof covering: Shingles, tiles, etc., that protect the decking from weather.
  • Drainage: The features of the roof's design such as slope, shape, layout, etc., that determine its ability to shed water.
  • Flashing: Sheet metal laid into the various joists and valleys of a roof system to prevent water leaks.

Roofing Pitch

Perhaps the most important–and perhaps least obvious–feature of your roof in determining the durability of your roof is pitch. Also known as "slope," pitch is the change in roof height (or rise) for a horizontal distance (or run). Usually expressed as "4 in 12," with 4 inches of rise to 12 inches of run, pitch weighs heavily in determining the type of roofing material that can be utilized on any given roof. Because a higher (steeper) pitch provides better drainage, generally speaking, the more pitch a roof has the longer lasting it will be.

Knowing the approximate pitch of your roof can be helpful for making many roofing repair and replacement decisions. There are many methods of determining the pitch of your roof; the simplest is to measure it directly. To do this, you will need a 3- foot board, carpenter's level and a ruler. Begin by laying the board flat on the roof, running straight up and down the slope. Then mark a point on the level that is 12 inches from one end and place the end of the level from where you measured near the top of the board. Next, raise the other end of the level until it is "level." Hold the ruler perpendicular (the two will cross each other and form an "X") to the level at the 12-inch mark; measure from the board to the bottom of the level. The distance you find here will give you the "rise" portion of your roof's pitch. For example, if your measurement is 6 inches, you have a "6 in 12" pitch.

How To Tell If Need a New Roof

There's nothing more frustrating than a leaky roof! Dashing around with mops and buckets during a rainstorm could put a damper on any occasion; seeking out the source of the leak(s) can be even more exasperating. (Since water runs downhill, leaks are seldom straightforward. It's actually quite rare-even on flat roofs-for leaks to stem from a source directly overhead.)

Most roofs–even those made of metal–will eventually wear out. The smartest option is to maintain your roof with regular repairs and, when the time comes, to replace your roof before problems absolutely force you to do so. (This ounce of prevention is, indeed, worth the effort. Remember, your roof protects everything in your home from the outside elements; even a small leak can become a costly proposition when furnishings and belongings must be replaced.)

Since our home's roof is "over our heads" and is also something that we see on a regular basis, it is easy to miss signs of deterioration. An annual inspection will probably identify most roof problems. To do this, you need to view your roof from several vantage points.

First, stand at a distance from your roofline so that you can see the entire structure. This will reveal any obvious problems and give you an overall view of the situation. Pay special attention to the ridge and rakes, since this is where roofing material detaches from first. Then you can get up close and personal with the construction and further assess the damage.

When Inspecting your roof for damage, look for:
    • Loose or popped nails
    • Loose or missing flashing around vent pipes, chimneys or wall junctions
    • Cracks or gaps in caulked areas
    • Holes in the valleys
    • Rotting

(To assess this, test the pliability of material at the
eaves using a putty knife. You should be able to push in
a screwdriver's tip no more than one-half inch.

Finally, you should inspect your roof from the inside. To do this, enter your attic and inspect the underside of the structure. (You should do this even if you have not witnessed leaks in your living quarters; there could easily be undetected leaks in the attic that will cause problems down the road.) Look for the obvious signs of water damage: stains, matted or crusted insulation, etc.

Even if your inspection (or, if the leak found you instead of vice versa, your interior downpour) reveals leak problems, it does not necessarily mean that obtaining a new roof is imminent. The age of the roof and the signs of deterioration ultimately determine if repairs are a viable option or if you will require complete roof replacement.

The signs of deterioration on any type of roof system can be attributed to a combination of abuse from the sun's ultraviolet rays, storms, insects and temperature change adjustments. (Ultraviolet rays are probably most damaging, so it is quite common for one area of your roof–that which receives the most intense sun for longest length of time each day–to suffer more severe deterioration than others.) Damage caused by termites, hail, wind, rotting or settling of the house structure or chimney is frequently hidden from view.

FACTORS THAT CAN CAUSE PROBLEMS WITH YOUR ROOF


SUN Heat and ultraviolet rays cause roofing materials to deteriorate over time.

RAIN When underneath roofing, water can work its way to the deck and begin to cause rot.

WIND High winds can lift the roof edges and force water underneath.

CONDENSATION The buildup of relatively warm, moisture-laden air in a poorly ventilated attic promotes decay of the wood sheathing and rafters.

MOSS & ALGAE Moss can grow on wood shingles and shakes if they are kept moist by poor sunlight conditions or bad drainage. Algae also grows in damp, shaded areas on wood.

TREES & BRANCHES Trees and branches should be trimmed away from the house to eliminate damp, shaded areas, and gutters should be kept clean to ensure good drainage.

MISSING OR TORN SHINGLES No longer offer your roof complete protection; there are missing "links in the armor" that shields your home from the elements.

SHINGLE DETERIORATION When shingles get old and worn out, they curl, split, and lose their waterproofing effectiveness and are more easily blown off, torn, or lifted by wind gusts.

FLASHING DETERIORATION Many apparent roof leaks really are flashing leaks around chimneys, vents, skylights and wall/roof junctions.

Finding Leaks in Your Roof

If a leak surfaces, carefully inspect the roof as described previously. Denote with spray paint any holes that you find. Also look for obstructions in the roof's valleys. (They can hold water and cause it to backup under the shingles.)
If, after a thorough external inspection, you are unable to locate any obvious sources of the leak, it's time to do an internal examination of your roofing structure. To do this, you should enter your attic on a bright, sunny day. Then turn off any lights and cover any windows in the attic to darken the space. Any light then seen shining through will reveal cracks or holes from which your leak may surely stem. Be sure to also inspect the areas around vent pipes, chimneys and skylights; these are places that have had the roof decking cut and resealed, so they are often culprits for broken seals or flashing. Should all else fail, you may need to flood the suspect area of the roof with your garden hose while someone in the attic watches for the drip to appear.

Replacing and Repairing Shingles

Because shingles are small, self-contained units, they are easily replaced without disrupting the rest of the roof. Your tools of the trade for this task will include spare shingles, nails, roofing cement and caulk. If, upon closer scrutiny, you find that the entire roof is badly worn or that the damage is more extensive than you had estimated, you will likely need to replace the entire roof.

It is best to have a professional roofing company do any major roofing job; expert assistance, in this instance, is well worth the expense if, for nothing else, the headaches and hassles that it can save you. Also, deciding to make replacing your roof do-it yourself project and then calling in last-minute help from professional roofers can end up costing you as much–and perhaps even more–than gaining well-planned professional for assistance to complete the entire job.

How to Maintain Your Roof

No matter your climate or location, your roof is under year-round assault from rain, sun, wind, and possibly ice, hail and snow. Your best offense against this ongoing onslaught is a good defense: regular maintenance.

To maintain its integrity, keep your roof as free of debris as possible is critical to the integrity of any roof system. Also although it's highly doubtful that you'll have the urge to linger on the rooftop-traffic should be kept at a minimum. Only walk on your roof when it is absolutely necessary to perform maintenance such as cleaning the gutters, skylights or the roof itself.

The most common do-it-yourself roof maintenance projects you may undertake are those of finding and fixing leaks and replacing loose or missing shingles.