Multiple roofing layers tend to decrease a roof's resistance to hail. Make sure to check local building codes, as some building codes and ordinances restrict the number of roofing layers a house may have. Another issue to consider with wood shingles when applying a new roof over the wood shingles is possible fungus problems. Installation of metal products over existing wood shingles is common as long as proper cuts for ventilations are observed.

Installing a roof over the top of an existing roof is generally acceptable under these guidelines: 1) A building cannot have more than two roofs; 2) No wet insulation can be left in place; 3) The roof structure must be able to handle the additional roof load; 4) The new roof must be attached to the roof deck to meet wind loads (it is not generally acceptable to adhere the new roof to the old roof)

Yes. Springhouse Shingles can be installed over your existing asphalt roof thereby eliminating expensive tear off and disposal fees.

For pre-existing conditions we recommend Shingle Shield Roof Cleaner, which is specifically designed to clean roofs prior to application of the roof protector strips. Other cleaning solutions may not be effective against these organisms, and may harm your roof or plants.

Yes, but the preferred method is removal. The Uniform Building Code allows two (2) roofs on commercial (flat) buildings and three (3) roofs on residential(steep) buildings. Removal allows for inspection of the substrate, and the elimination of any wet, rough, and/or unstable existing materials.

Yes in some cases. But you should have a professional roofer inspect the current conditions of your existing roof.

No. When asphalt shingles are applied over slate, the nails are driven through the slates. This method leaves holes in the slate if the nails and shingles are removed. New slate must be applied to ensure a watertight roof. Yes. Even new slate roofs will shed a few slates. It is a good idea to visually inspect a slate roof at least once a year. The owner of the property can do this annual inspection. Any slates that are seen to be missing, sliding, or broken should be replaced.

If you are committed to your home for years into the future, a metal roof will offer you much greater value and a lower life-cycle cost than the most common and inexpensive roofing products, even though the initial cost seems higher. This is because you will not need to replace this roof for 50 years or more, whereas on average, asphalt shingle roofs are being replaced every 15 years. We like to say that a metal roof is "the last roof you'll ever have to buy."

the GRP roof systems we use lend themselves to over-roofing (providing the existing deck is in serviceable condition) it is not always necessary to strip the existing roof covering and decking. An initial site survey should establish whether the existing deck should be replaced as per building regulations.

Most insurance companies will not cover pre-existing conditions for up to 24 months and most Chronic conditions are normally excluded from coverage even after the 24 months period. Some insurers will allow pre-existing conditions to be covered from the inception of the policy but this is on a case by case basis and may be subject to a premium loading.

Grace underlayments are excellent air and vapor barriers. When used in full roof coverage applications, adequate ventilation must be provided to avoid condensation problems within the roof structure or the attic space.

In most cases a metal roof can be installed over composition roofing materials. The condition of the roofing substructure will be a factor and the building codes in your area will dictate the number of roofing layers allowed. Because of its light weight, relative to all other roofing systems, many local codes will allow installation of a metal roof over multiple roofing layers where other systems would be prohibited.

A:A PV system can be installed on any well-structured roof. Typically asphalt shingles are easiest to work with, while slate is the most difficult. If your roof is older and needs to be replaced in the very near future, you may want to replace it at the time the PV system is installed to avoid the future cost of removing and reinstalling your PV system. PV systems are also available that integrate PV cells into the roofing materials themselves.

with any roofing product, the best procedure to use when re-roofing is to tear off the existing roof and use industry approved underlayments to assure the best performance over the life span of the roof. But this can be done. It will not affect the material warranty, but it will affect the wind and fire ratings. So usually the benefits of tearing off out weigh going over an existing roof.

One of the benefits of steel roofing is that is lightweight, which allows it to be installed over existing roofing material. Local building codes and your roofs substructure integrity must be addressed to reveal this answer.