Selecting a Roofing Contractor

There are many roofing contractors-good and bad-honest and dishonest. Some of the shadiest characters claim to be roofers. They taint the trade for the majority of roofing contractors who perform a quality, timely, honest, service oriented business.

• Get recommendations from others and checkout their roofs.
• Ask for references from potential roofing contractors & check them out.
• Ask if the contractor is insured for damage and on-the-job accidents. Ask him to have their insurance company fax or email you proof.
• Don’t pay the roof contractor upfront for the entire job. A reputable contractor has good enough cash flow to order materials. It’s OK to pay the contractor for the materials after they are delivered to your home. Don’t pay the final payment for the job until the work is completed, including the cleanup.
• Get several estimates for the same job (at least 3). Make sure the quotes cover the same materials and workmanship.
• A qualified contractor will help you obtain financing, if you need it.

Before signing a contract make sure that the contract states in detail:

• the work to be completed
• the specific materials to be used
• completion date and penalties
• warrantees & guarantees
• cleanup (removal of materials)
• total price
• method of payment

If you are financing the work make certain that the contract clearly states:

• purchase price
• amount of down payment
• balance owed
• number of installments
• finance charges
• interest rate
  
  
  

Roofing Code and Best Practices

While much of what is written below is from the N.Y. State Residential Roofing Code, it is common sense for any re-roofing job. The code is not stated verbatim to avoid confusion and I have added comments for clarification.

Recovering vs. Replacement

New roof coverings should not be installed without first removing existing (old) roof coverings under the following circumstances:

• Where the existing (old) roof is wood shake, slate, clay, cement or asbestos cement tile

• Where the existing (old) roof is water-soaked, or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing to be installed

• Where the existing roof has two or more applications of an type of roof covering already installed

With asphalt shingles, more than two layers of covering, when combined with the weight of snow, can exceed the weight supporting capability of the roof sub-structure.

Slope

Asphalt 3-in-1 shingles shall not be used in low pitch roofs (lower than 2/12). This type of shingle is not suitable for low pitch roofs as water cannot be easily shed from the surface and wind can blow rain up and under shingles to the unprotected surface of the roof structure.

Ventilation

Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of the roof rafters (virtually all home types) shall have cross ventilation for each separate space by ventilating openings protected against rain or snow. The total net free ventilation area shall not be less than 1/150 of the (floor) space ventilated (if the square footage of the “floor” of the space is 1000 sq. ft. then 6.7 sq. ft. of ventilation is required).

The total ventilation area can be permitted to be reduced to 1/300 of the (floor) space, provided that 50%-80% of the required ventilating area is provided by ventilators located in the upper portion of the to-be-ventilated space, which should be 3 feet above the eave or cornice (gable end vents) vents.

ASHI (American Society of Home Inspectors) recommends that the total vent area be 1/300 of the floor space of the attic for all areas where the roof slope is two in twelve or greater. At least 50% of the vent area should be at the soffits with the remainder at the ridge, roof, or gable vents. If the soffit vents provide less than 50% of the venting, the result can be negative pressure in the attic space causing warm moist air to be sucked out of the living space (through the ceiling, ceiling fixtures, around openings, etc.). Where the slope is less than two in twelve or for a cathedral roof with no attic space, the vent area should be increased to 1/150 of the roof area.

Ice Protection

An ice barrier that consists of at least two layers of underlayment cemented together or a self-adhering polymer modified bitumen sheet (as an ice and water shield) shall be used in lieu of normal underlayment. The ice barrier shall extend up from the eave’s edge to a point at least 24 inches inside the exterior wall line of the building.