Approximately five years after installation roofs can begin to show signs of dark streaks. The dark streaks usually appear on the north-facing slope of the roof and are mistaken for dirt or granule loss. These streaks are commonly caused by algae growth that is prominent in areas of the roof that receive less sunlight.
Roof slopes that are shaded or receive little sunlight will hold moisture for a longer period of time which can result in algae growth. The discoloration or streaking is an aesthetic concern and does not affect the life of the roof system or its waterproofing characteristics.
Zinc strips can be added to a ridge of a roof to prevent algae from forming. Various solutions can be used to remove algae growth, although this is a temporary solution, as it will grow back.
It is important to use extreme care when attempting to remove discoloration as many harsh treatments or power washing can harm your roof system and result in granule loss.
The most common cause as to why water is dripping behind a gutter system is because there is no drip edge installed.
Drip edge is a key component to any roof system. Drip edge is a metal flashing installed under the first row of shingles on a roof slope. Drip edge has a projecting lip which directs the flow of water into the gutter system.
Drip edge should be installed on the lower eave of your roofing system underneath the ice and water shield. The drip edge also provides an extra bonding edge for the ice and water membrane to adhere to
You should never install new shingles over the old shingle roof system.
Your roof system will not be eligible for a warranty if you do not remove the existing shingle roof system before installing the new system. Installing over the old shingles can also cause unusual shapes to form in your new roof system and the roof system will not look smooth and level.
If the old roof system is not removed it will not be possible to inspect the plywood deck sheathing for rot or deterioration that can become a much larger problem in the future. Moisture from the previous roof system can be trapped under the new system and the increased surface temperatures from having two layers of shingles can accelerate roof aging.
No. Proper ventilation of a roof system occurs when the soffit area at the bottom of an attic pulls air inwards and the roof vents in the top of the attic space release air for complete attic air transfer. When using multiple types of roof vents a stronger roof vent can cause a weaker roof vent to become an intake. The weaker vent can begin to pull outside air inwards rather than release air from the attic space and can result in a reduction in air transfer.