Doing The Job

Doing The Job

Building Codes And Permits

Building codes vary greatly depending on where you live. Any roofing project you undertake must comply with building codes applicable to your jurisdiction. Certain areas of the country have region-specific building codes of compliance. For example, Miami-Dade County in Florida enforces building codes to ensure homeowners have the best protection against weather events such as hurricanes.

Before you begin any roofing project, it is vitally important to obtain the applicable building code. Contact your town’s municipal building to obtain the proper building permits and for the correct building codes for your area. If you do not obtain a building permit for your roofing project, you may be subject to significant fines and penalties.


What Materials Will I Need?

GAF has made it easy for you to determine the materials you will need for your new roof. Our Roof Wizard walks you through four simple steps: selecting your shingle style, your shingle color, your warranty coverage level, and your roof accessories.

Try GAF's Roof Wizard

View the different colors of our Three-Tab, Timberline®, and Designer shingles here.

Try out shingle styles and colors on a home like yours! Visit our Virtual Home Remodeler.

Important Note: The best GAF warranties—including those that cover workmanship of the installer—are only available when a roof is installed by a GAF factory-certified contractor. Find one here. See warranties for coverage and restrictions.  


Estimating How Much Material You Will Need

To estimate the amount of material you need for your roof, you must first determine your roof's slope. The slope is the rise over the run. A tool called an inclinometer should be placed on the top ridge of the house and will allow you to record the measurement of the slope. Then you must determine the total square footage. Measure all sections of your roof including the hips, valleys, ridges, eaves, rakes, and any overhangs.

Once you have all your measurements, use them to calculate the total square footage. You can find numerous roof calculators and measuring guides online to assist you in this process. Remember to estimate the amount of tear-off debris you will need to handle as well at this time.

Don’t think you’re up to it? Your best option is to find a factory-certified GAF Master Elite® Contractor near you to do the job.
Find A Contractor


Estimating Roof Ventilation Requirements

Deciding on the proper vent and the amount of ventilation needed is critical. Always consult your local building code for balanced attic ventilation requirements in your area.

To calculate the amount of ventilation you need for your home in the U.S., visit GAF's Ventilation Calculator.

Visit The Roofing Project Planning Center

Get the knowledge and resources you need to plan for your project.

Find a GAF Distributor OR Retailer Near You

Get all the materials you need for your roofing or building project.

Choosing The Best Value Shingles For Your Home

When looking for a new roof, rest assured you’ve come to the right place. Not only because most GAF shingles offer a Lifetime Ltd. Warranty1 for peace of mind, but because you’re almost certain to find the right combination of style and color to suit your taste.

Good:  For projects on a budget, GAF Three-Tab Shingles will give you basic, affordable protection for your home.

Better:  The #1-selling shingles in North America, Timberline® Lifetime Shingles offer the very best combination of performance and value that you can get for your home.

Best:  GAF Lifetime Designer Shingles are our top-of-the-line asphalt shingles. Offered in a wide array of styles and colors, these shingles come in two categories to choose from depending on your budget: the Ultra-Premium Collection and the Value Collection.


Tear-off Or Overlay?

You should tear off old roofing to repair or replace rotted or deteriorated decking and framing, to replace bad flashing, to install proper soffit ventilation, to install leak barriers, to seal critical leak areas such as valleys, dormers, skylights, chimneys, roof slope transition areas, ice dam areas, and wind-driven rain entry points, and to comply with building codes.

Many top contractors feel that you should remove old roofing on every project, but it is acceptable to overlay when the existing roof is lying flat, when flashing and roof deck protection are still performing, if there have been no previous leak problems, and if ventilation at the soffit is acceptable or attainable without tearing off roofing. Make sure to check with your local building codes to see if an overlay is allowed.


Recycling And Waste Disposal 

The most important step to preparing your roof for recycling is to pre-sort materials as they come off the roof. You can recycle shingles, felt, or other asphaltic underlayment, and nails. The goal is to get these materials into a separate pile or container. Doing this pre-sorting can even save you money, because you’re making it easier for the recycler.

Wood, metal, and other mixed jobsite debris should be kept separate. Many recyclers will allow you to place these materials on top of the load—maybe with a tarp separating the two layers—but it must be easy for the recycler to separate the materials, otherwise the load will not be recycled. Check with your recycler first.

Find a recycler near you. Many transfer stations have recycling arrangements. Be sure to call in advance to see if there are any special requirements.

If you decide to have a professional install your roof, use the GAF Contractor Locator and look for the Certified Green Roofer designation—these are professional roofing contractors who have adopted a number of sustainable business practices including shingle recycling.

1See GAF Shingle & Accessory Ltd. Warranty for complete coverage and restrictions. The word “Lifetime” refers to the length of coverage provided by the GAF Shingle & Accessory Ltd. Warranty and means as long as the original individual owner(s) of a single-family detached residence [or the second owner(s) in certain circumstances] owns the property where the shingles are installed. For owners/structures not meeting the above criteria, Lifetime coverage is not applicable. 
Previous DIY topic

Read More
Next DIY topic

Learn Roofing Safety

Thinking about a DIY roofing job?
Read More
Contact GAF Contact GAF
Professional Installation Find A Contractor
Pricing and Where to Buy DISTRIBUTORS & RETAILERS