It is not necessary to remove the plastic cellophane tape that is applied on the back of shingles. This tape is applied during the manufacturing process and prevents the shingles from sticking together in the package.
The following steps are recommended for the proper removal and replacement of damaged shingles.
Notes: In hot weather, cool shingles with a water hose to allow easy separation of the shingle tabs; In cold weather, avoid excessive bending of the shingles as it could cause cracking.
Step 1: Loosen adhesive under tabs in the second row above the damaged shingle. Lift tabs and withdraw the exposed nails.
Step 2: Loosen and lift tabs in the first row above damaged shingle and withdraw exposed nails.
Step 3: Loosen tabs of damaged shingle which can now be removed.
Step 4: Place new shingle in the same position from which the sample was removed and re-nail. To reseal shingles, lift tab and apply 1” diameter spot of shingle cement under each tab. Press tabs down into the cement. Repeat nailing and cement procedure for any other rows that are damaged.
Ventilation is a crucial factor in the life of a roofing shingle. Heat build-up in the hot summer months, as well as the cold weather of winter will accelerate the aging process of your asphalt roofing shingles. Proper air circulation, regardless of the weather outside, will greatly reduce the chances of leaking, blistering, distortion, curling, rotting of wood structure, wet insulation and many other potential problems.
It is also important to note that adequate ventilation is required to validate the shingles manufacturer warranty. In Canada for example, minimum requirements prescribed in the National Building Code must be respected. In all cases, the most stringent applicable building codes must be followed.
Leaking roof: Normal weathering of asphalt roofing shingles will not cause leaking.
Flashings are crucial areas that must be watertight to avoid leaks. These are the areas most frequently identified as the causes of leaks.
Damaged shingles leave the roof exposed to leaks and should be repaired without delay.
When installing shingles take note of the alignment of the cutouts, depending on the type of BP shingle chosen, as well as the nailing location as these areas are crucial to the ease with which water can infiltrate a roof. They should always be covered by overlying shingle tabs.
Inadequate ventilation can cause ice damming, frost and condensation accumulation. These problems can all be easily prevented with proper air circulation.
This is one of the biggest misconceptions about metal roofing. People who’ve experienced barns or other structures where the metal roofing is visible from the interior can recall the “pinging” noise that rain makes when it hits the roof. In these applications, the metal is installed without a solid roof deck, so there is no dampening effect when something contacts the roof. In residential applications, metal roofing is installed on a solid plywood deck, just like shingles. When installed in this manner, metal roofing is no noisier than other roof materials.
Fishmouthing looks like buckling but it is usually random on the roof. The front edge of the shingle is raised, and tapers back into the shingle. Although it does not usually affect the durability of the shingle, it should be addressed. Possible Causes:
• Moisture build-up in the attic can cause wetting & drying cycles in the shingles. Improving attic ventilation can prevent this.
• Installing wet shingles on a dry day, or dry shingles on a wet day will almost guarantee the appearance of fishmouthing.
• Nails that are ‘popping’ out can also cause fishmouthing. Simply correct the position of the nail.
This phenomena is mainly an aesthetic issue that can be repaired in most cases. The most common repair method would be to use hot melt adhesive to glue down the distorted shingle rendering it flat. To proceed, the sealant bond of the affected shingle should be broken first. These types of repairs are best carried out in mild (not too hot) weather conditions.
Corners of shingles turning up is referred to as Curling and it is generally caused by excess moisture attacking the underside of the shingle. Inadequate ventilation causes the entrapment of heat and moisture in the attic. This will eventually penetrate the roof deck and cause the shingles to curl. Improving air circulation within the attic space can stop the progress and rectify the situation if the curling is not too severe. In some rare instances, curling can reveal itself only under cold weather conditions. This would be referred to as winter curling. The corners of the shingles will slightly curl up from the roof deck when cold, and then lay flat again during warmer weather. This is especially prevalent during damp winter conditions when frost forms on the top surface of the shingles. This cooling on the top surface will cause the shingle to contract while at the same time the underside of the shingle in contact with the roof receives a certain amount of passive heat from the attic space. The variation of temperature between the top side and underside of the shingle will result in some minor curling. This does not affect the shingle’s durability and effectiveness to shed water.
Granule loss is a normal process in the weathering and aging of any asphalt shingle. Common causes of additional granule loss:
• Traffic on roof
• Shingles applied on very slight slopes (2” in 12” or less), are prone to increased levels of granule loss due to the poor drainage capabilities of the roof.
A certain amount of granule loss is to be expected. Shingles are made with an excess of granules on the surface called “hitchhikers”. If the underlying asphalt is prematurely exposed, the appearance and service life of the shingle may be affected.
Usually visible on North-facing light-colored roofs ranging from five years old, discoloration or streaking is sometimes mistaken as dirt, moss, or granule loss. It is actually caused by algae growth that propagates in areas of the roof that receive less direct sunlight, and thereby retain a higher level of moisture. Although most noticeable on light shingle colors, the algae affects all asphalt shingle roofs, including darker colors. The discoloration caused by the algae is in no way indicative of a shingle defect. This is an aesthetic concern and will not harm the shingle or shorten the life of the roof. The algae discoloration is difficult to remove from roofing surfaces, but may be lightened using various solutions available at most lumberyards.
Cleaning the shingles is a temporary solution as it will eventually grow back due to higher humidity levels in areas of limited exposure to direct sunlight. The cleaning process will have to be repeated every few years. Care must be taken when cleaning the algae as to not remove excessive amounts of granules that are attached to the surface of the shingles.
Small bubbles or bumps will sometimes develop on the surface of roofing materials. This is referred to as blistering that will generally appear within 2-3 years of product installation. Small rash blisters, 7mm (1/4”) or less, will not normally affect the performance of the shingle. Larger blisters, often up to 2.5cm (1”) in diameter, can shorten the life of the shingle as they often break exposing the underlying components of the shingle. Causes include trapped moisture, inadequate ventilation of the attic, excessive use of adhesive, or the use of non-compliant adhesive.
Buckling shingles can become humped or wavy, usually running in a straight line up, or across the roof.
Deck or felt movement often caused by varying moisture levels in the material under the shingles. The shift will cause the nails to move in accordance with the deck forcing the shingles closer or farther apart depending on the situation.
• Improper nailing – nails will ‘pop up’ creating the buckling effect.
• Shingles nailed too tightly together.
• Thin decking (3/8”) over 24” centers can be the cause due to clips, meant to hold the decking in place, coming lose or coming off.
Depending on the cause of the buckling, improving attic ventilation to eliminate excess humidity, removing fasteners and refastening or replacing distorted shingles can be some possible solutions.
All shingles, whether organic or glass based, will be subjected to UV rays from the sun, causing the asphalt coating to dry, loosening the granules covering in the long run. Other visible signs are pieces of torn shingles, curled tab corners as well as centerline cracks.