How to Choose the Right Roofing Contractor
It is very important to set up a face-to-face meeting to discuss your needs and their qualifications. Be sure to pay attention to the attitude of the contractor. Good contractors take pride in their work and will be enthusiastic about the possibility of helping you with your problems. Feel confident that the contractor is truly interested in your project.
Find a roofing contractor who knows good roofing practices, roof flashing details, how to handle problem spots on building roofs, and alternative roof covering products: shingle types, grades, colors, low slope roofing, flat roofing materials, etc. A competent roofer will provide you with sound advice on products, reasonable explanation of procedures, and, most important-solid results - no leaks, and a durable roof.
Important questions to ask:
- Is the contractor licensed? Does the contractor have liability insurance?
- Will the contractor provide a list of references?
- Does the contractor provide a “good workmanship” warranty?
- Does the contractor provide the homeowner with a copy of the warranty issued by the manufacturer of roofing materials, and has it been thoroughly explained to you?
- Does the contractor offer an extended and/or upgraded warranty through the manufacturer? Most manufacturers offer this to reputable roofers.
- Does the contractor thoroughly inspect the roof (and anything else that can leak), prior to the estimate and share his findings and concerns?
- Does the contractor provide a written estimate including specifics on the work to be done, options on the work to be done, the timeline for completion (including clean-up) and the cost all on company letterhead?
- Is the contractor going to supervise all phases of the project and provide final inspection?
- Does the contractor have a cell phone or contact number in case of emergency, and will he be available weekends?
- Does the contractor follow all local and state codes and restrictions?
- Does the contractor show commitment to the profession by being a member of any regional or national industry associations, such as NRCA?
Keep a healthy skepticism about the lowest bid. If it sounds too good to be true, it probably is. Many fly-by-night contractors’ below-cost bids seem attractive, but these contractors often are uninsured and perform substandard work. Remember, price is only one of the criteria for selecting a roofing contractor. Professionalism, experience and quality workmanship also should weigh heavily in your decision.
Tear-off or Overlay?
The question often comes up about whether an existing composition shingle roof should be torn off or if an overlay (or recover) is possible. Overlays save on time, labor, and disposal costs. If the existing roof has only one layer, lays flat, and there aren’t any problems with the roof deck, removal is not necessary.
Regardless of whether you overlay or tear off, you should properly ventilate your attic. In almost all cases, continuous soffit and ridge vents will provide maximum cross ventilation.
If any of the following are true, a complete tear-off of the existing roof system(s) should be considered.
- Too many layers. If a roof has more than one layer of roofing, the roof should be torn off. In most cases this is a code requirement. Codes rarely permit more than two layers of roofing. To determine this, all you need to do is contact your local building inspections department.
- Bad decking. if spongy areas are noticed when walking on a roof, or if you see sags between the rafters or trusses, there's a chance that some of the roof deck may be deteriorating or be damaged. Deterioration can be attributed to dry rot or delamination of the plies in the plywood due to glue failure. Dry rot is wood rot caused by certain types of fungi and if it isn't taken care of, it can spread. If there is suspicion of bad decking, then a full tear off should seriously be considered.
- Ice dams. ice dams can be a big problem. In areas where there the average January temperature can be below 30°F, and no ice and water protection membrane is present on a roof, then a full tear off should be considered. Twenty year old buildings with no ice and water protection and no prior problems, can suddenly experience thousands of dollars in damage when a freak cold front hits.
- Incompatible shingles. if a heavy weight architectural style shingle is used to cover a light weight strip shingle such as 3-tabs, then the roof will look good. However, if a light weight shingle is used to cover a heavy weight shingle, the light weight shingles have a tendency to show all the bumps and ridges (called telegraphing) and won't look good.
- Existing roof is in poor condition. if the existing roof is in really poor shape, such as tabs being severely curled or if the rows are crooked, then complete tear off and replacment should be considered.
- Shorter Life Span. There is no known documented research, but most roofing professionals agree that with an overlay, the average lifespan of the shingles will be shortened by about 10%-20%.
Ventilation and insulation are key
One of the most critical factors in roof system durability is proper ventilation. Without it, heat and moisture build up in an attic area and combine to cause rafters and sheathing to rot, shingles to buckle, and insulation to lose its effectiveness.Therefore, it is important never to block off sources of roof ventilation, such as louvers, ridge vents or soffit vents, even in winter. Proper attic ventilation will help prevent structural damage caused by moisture, increase roofing material life, reduce energy consumption and enhance the comfort level of the rooms below the attic.In addition to the free flow of air, insulation plays a key role in proper attic ventilation.
An ideal attic has:
- A gap-free layer of insulation on the attic floor to protect the house below from heat gain or loss.
- A vapor retarder under the insulation and next to the ceiling to stop moisture from rising into the attic.
- Enough open, vented spaces to allow air to pass in and out freely.
- A minimum of 1 inch between the insulation and roof sheathing.
The requirements for proper attic ventilation may vary greatly, depending on the part of the United States in which a home or building is located, as well as the structure's conditions, such as exposure to the sun, shade and atmospheric humidity. Nevertheless, the general ventilation formula is based on the length and width of the attic. NRCA recommends a minimum of 1 square foot of free vent area for each 150 square feet of attic floor—with vents placed proportionately at the eaves (e.g., soffits) and at or near the ridge.