The purpose of your home’s roof is to protect your home in all kinds of weather. The roof is the most vital factor in protecting your home and enhancing its looks and value.
Most types of shingles are placed partially atop one another, like the feathers of a bird. Roof shingles are at least two deep and have an extra layer along the edge. For additional protection against leaking, flashings are feathered in under the shingles at several points. Think of flashings as special purpose shingles; they interweave with other roofing materials to help shed water and may be either metal, rubber, or the same type composition as the shingles. You will find flashings in valleys (where two slopes meet), around chimneys, plumbing vents, dormers and anything else that penetrates the roof’s surfaces.
Since there are numerous styles of roofs and roof coverings, we may not cover the type of roof on your home; if that is the case you should contact someone who is familiar with your type of roof.
One of the most common types of roof covering, and by far the most popular and least expensive is an asphalt composition shingle. The asphalt composition shingle is composed of roofing felt saturated with asphalt and coated with mineral granules. Some newer ones have a fiberglass base for greatly improved weather and fire resistance, with a life span of 15 to 25 years. No matter what type of roof you have, we would have to know when it was installed to be able to tell how long it will last and we usually don’t know the answer to that question.
Another common type of roof covering, which is slightly more expensive, is wood shingles. The life span of wood and asphalt shingles is about the same, depending on the weight of the asphalt shingles and the grade of the wood shingles. If your home has wood shingles, you will see stains on the bottom of the shingles in the attic. These are not water leaks, but the natural oil stains of the shingles. At times you may see daylight in your attic. This is not necessarily something to be concerned about, water flows downward but light can shine upward, and this is what you may be seeing. Your inspector is experienced and understands this and will thoroughly inspect the roof for water leaks.
Wood shakes are similar to wood shingles but much thicker, rustic looking and more expensive than wood shingles. Wood shakes generally last longer than shingles because they are thicker. A difference between wood shingles and wood shakes is the way they are installed. Felt roofing paper is placed under the wood shakes. The felt paper actually sheds the water and the wood shakes protect the paper from the sun’s deteriorating effects.
Slate or Clay Tiles
Clay tiles are used more in the southwest and slate tiles in the east. Tiles are generally much more expensive and break very easily. These types of tiles should not be walked upon unless you know what you are doing.
Built Up Roofing
Built-up roofing, unlike shingles, shakes, slate and tiles, must be absolutely waterproof because it is flat. This type of roof is used only on flat or very low pitched roofs and is usually fabricated on the job by laminating layers of felt with asphalt or coal tar and then topping with gravel. Often there will be bubbles on a built up roof, but this does not necessarily mean the roof needs to be replaced. However, do not pop any bubbles while you are walking on the built up roof as you may create leaks. Generally these areas can be repaired without too much trouble.
FACTORS AFFECTING YOUR ROOF
Checking your roof: After a storm you should always check your roof for missing shingles, missing rain caps on furnace and water heater vent stacks, and natural gas appliances that require vents. You don’t necessarily have to climb on your roof to check these out, using binoculars works just as well and is much safer. Make a habit of looking up at your roof whenever you approach your house, either from the front or back yards. This way you will notice immediately if something is wrong. Furnaces are expensive and a missing rain cap on the vent stack can shorten the life of the heat exchanger by more than half. Note that not all pipes sticking up on your roof need rain caps, some of them are plumbing vent pipes.
Too Close for Comfort: Tree limbs can also affect your house. A limb lying on the roof and blowing back and forth can cause considerable damage. Bear in mind, if limbs are closer than thirty six inches to the roof, they can be a ladder for squirrels, roof rats and carpenter ants. We all know about and dislike rats, but what about cute little squirrels? Squirrels are a member of the rodent family, and can do as much damage as rats, if not more, chewing through electrical wires, plastic vent pipes and siding. They can literally rob you of your peace and quiet.
Cover up: Often, especially in the fall of the year, leaves and small tree limbs will build up on your roof, particularly in the valleys. Although roofs are designed for water to flow downward, when this happens, it can cause water to back up and leak into your attic and home. We don’t like to do this because if the debris has been there too long it may be stuck to the singles and will damage them. We encourage you to be careful about removing debris, and the possibility of damaging your shingles, we also suggest you keep people off of your roof unless they are professionals.
Ventilation: Something else you need to consider is proper ventilation in your attic. Proper ventilation can lower the cost of cooling your home by 60 percent, prolong the life of roofing materials, and prevent premature deterioration of attic insulation materials. Bear in mind, a little extra ventilation in your attic is better than not enough. Two types of ventilation are wind turbines and power vents. Installing wind driven turbines is an easy do-it-yourself project and the ideal time to install them is when you are having your roof recovered. Remember that they must turn freely or they will leak water into your attic. We have been asked which is best, an electric power vent or a wind driven turbine. Studies show that any savings by power venting are offset by the cost of the electricity it requires. (It is also interesting to note that power ventilators have a history of having a short life span.) Extra consideration is needed when installing any form of attic ventilation in attics with the older gray plastic style of ductwork.