Thanks for stopping by. We’d like to share with you our GAF roofing process, so that you’ll know what to expect. In providing the GAF limited lifetime System Plus warranty, it’s critical that the details are done right; otherwise, you don’t really have a warranty. The following steps are not just good ideas, they are requisite for GAF to honor your warranty.
Step One in the GAF Roofing Process – Tear-Off
Stripping the old roof down to clean decking is important for multiple reasons:
- Exposes any weak places in the decking. For a new roof to function properly, it needs a solid base. Excessive gaps in the plywood and/or plywood rot are not just dangerous for anyone that might walk the roof, they cause shingle nails to wiggle and create leak spots in your roof.
- Get the weight of the old shingles off the home! Shingles weigh a lot (some 200-250 lbs/”square”; 70-80 lbs/bundle; or 2-2.5 lbs/square foot), and it’s always good to get the extra dead-weight off your home. While placing a second layer of shingles may be permitted in some jurisdictions, anything beyond that (a third or forth layer) is prohibited. There’s really no reason to leave the old shingles up there, and even if you do, someone will eventually have to tear them off, so it’s not saving any money in the long-run.
- A third reason to strip the roof is to prevent “telegraphing” of old shingle patterns through the new layer of shingles.
Step Two in the GAF Roofing Process – Replace Bad Decking and/or Fascia
We recommend going back with “like” material – same kind of decking (i.e., plywood vs. OSB) and same thickness. A slight change in thickness can be seen through the shingles, surprisingly. Also, it’s good to support the edges (and if necessary, the middle) of the plywood, as small pieces of replaced plywood (say, 16″ x 16″) lack the rigidity due to size that large 4′ x 8′ sheets of plywood have. If your roofer isn’t careful to support the new plywood patches, you can easily have a spot where a future roof-walker can break the patch and fall through! In general, we prefer plywood over OSB as a roof decking material, because it reacts less to water. When a leak occurs on an OSB deck, it will swell and rot; whereas on a plywood deck, a leak will often not damage the plywood, or will only damage the top ply of the plywood. Nevertheless, OSB has “taken the day” in new construction, and quite possibly 95 out of 100 new homes are decked with it. The home below came from “the good ole days,” and used 7/16″ plywood!
Step two also includes replacing any bad fascia. Once you remove rotted fascia, though, you often find rotted sub-fascia and/or rotted soffit, as in the picture below. The picture below also illustrates the importance of drip edge (the metal “trim piece” under the shingles, visible in the “after” part of the photo below) – this roof previously lacked drip edge, and a squirrel had managed to chew his way into the cornice and make a home there. In his spare time, he chewed on the wire going to the flood light! We found his dead corpse left in the cornice. Just another reason to install your roof correctly!
Step Three in the GAF Roofing Process – Install Drip Edge and Quality Felt Or Synthetic
GAF offers you some options for felt or synthetic – there is Shingle Mate®, Tiger Paw™, and Deck-Armor™. The Shingle Mate® is a high-quality felt, while the latter two options are synthetics. Tiger Paw™ is the best choice (in our opinion) for vented, asphalt shingle roofs (low-perm rating of less than 1 perm); whereas Deck-Armor™ is able to “breathe” (16 perms), which is perhaps good for conditioned, non-vented attic spaces. Low-permeability means an added layer of protection against rain and leaks. All of these options are going to lay flatter than typical felts, which is important for preventing “telegraphing” of waviness in the felt through the shingles. An added benefit for Tiger Paw™ and Deck-Armor™ is that they are very comfortable for roofers to walk on, which means greater safety.
It’s also important to install drip edge. Drip edge should go under the felt at the eaves, and over the felt on the rakes, for best protection. Drip edge serves at least the following purposes:
- Keep insects and animals out of the attic.
- Provide a flat surface that keeps the overhanging parts of shingles from sagging.
- Protect the roof edges from wind-driven rain.
- Provide a “lip” for water to “drip” off of – instead of running down (and prematurely rotting) the fascia boards.
Step Four in the GAF Roofing Process – Installing Starter Strips On the Eaves and Rakes
While GAF offers a few options on starter strips, we prefer their Pro-Start® starter strip. Starter strip might not make sense to you, but basically is just aids in holding the ends of the shingles down at the edges of your roof. When wind blows on your house, the edges are a very vulnerable place where it can get under the shingles and start to blow off parts of your roof. The GAF Pro-Start® starter strip is nailed firm to the edge of the roof, and a special bead of asphalt sealant on the edge of the starter strip holds the shingles that will be installed above. Many roofers use 3-tab shingles turned upside-down as the starter course, but the problem with this is that the sealant is 5″ away from the edge of the roof, where it needs to be. Also, this erroneous installation prevents nailing close enough to the edge to sufficiently hold down the starter.
Step Five in the GAF Roofing Process – Installing the Shingles!
We typically use a 6-hit nailing pattern, which increases the wind-rating of your GAF System Plus warranty from 110 mph to 130 mph (Category 3 Hurricane Wind Speed) when used in combination with starter strip on the eaves and rakes (also normal procedure for us). Further, we strive to keep the nails exactly where they are supposed to go – not too high, and not too low. If they are too high, your shingles can sag, de-laminate, or fall off over time; if they are too low, they are called “shiners” (they are exposed and can become a leak). It’s also important to keep an eye on shingle butt joints, to make sure that underlying nails are roughly 6″ away from the joint, to prevent a leak due to seeping water. We also watch out for “racking,” a corner-cutting method that makes installation quicker, but can also be seen from the ground in the final product (and makes it easier for wind damage to occur to your roof). Instead of “racking,” we “triangulate” the shingles, to keep a random look and provide maximum security against wind.
Step Six in the GAF Roofing Process – Properly Address Pipe Penetrations & Flashing Details
Almost all roof leaks occur around pipe penetrations (as in the photo above) or at flashing locations. These are areas where there is a discontinuity in the roof surface, and many roofers either don’t know what to do, or just don’t do it. GAF has a special, rigorous set of steps to ensure that any abnormality in the roof can be soundly addressed. For example, on pipe-penetrations, GAF calls for the installation of a roofing-underlayment patch, adhered to the felt/synthetic above the pipe, and emptying onto the shingles below. This way, if any water manages to get around the pipe boot, it will be diverted back out on top of the roof surface.
Then, Caldwell’s Roofing uses LifetimeTool.com boots to seal around the pipe. GAF has partnered with LifetimeTool.com to warranty their boots when correctly installed and used as part of a System Plus warranty. If you’re going to get a lifetime roof, make sure you get a lifetime boot!

Installing a LifetimeTool.com Boot to Seal a Pipe Penetration
After the boot is installed, the shingles are laid around it. Here’s a finished picture. We also used GAF’s ShingleMatch™ roof accessory paint to change the pipe from white to the brownish color in the photo. We can color match your pipes to help them blend in with the roof.
On dormer walls and other roof protrusions, step-flashing is the method-of-choice to protect against leaks. Here’s a picture of some below.
Step Seven in the GAF Roofing Process – Adequate Attic/Decking Ventilation
With 9 out of 10 homes lacking proper ventilation, it’s definitely a subject that “matters.” Codes usually call for a 1:300 ratio of NFVA (Net Free Ventilating Area) compared to the footprint of your attic space. Best practice, and some locations, require 1:150. Caldwell’s Roofing tries to shoot for the more stringent 1:150 if possible. Experts agree that not only is ventilation critical, it’s important to do it right. That means enough ventilation, and having it placed at the right spots (at a 50:50 “balanced ratio”). All of this may sound technical to you, but it’s what keeps your AC bills down, helps prevent microbial growth in your attic, and extends the life of your shingles (helping prevent “heat blisters” which adversely affect the longevity of your roof). Childhood asthma and itchy eyes could mean your attic isn’t properly ventilated (and is allowing microbial growth)! Basically, you need intake at the lowest parts of your attic (or, specifically, at the “eaves”); and you need outtake of the air at the top of your attic (at the “ridge”). This can be engineered in a variety of ways, including soffit vents, vented drip edge, GAF’s Cobra FasciaFlow® product, ridge vents, shed roof vents, power turbines, and so on. However, ventilation is something for professionals, as amateurs often end up worsening their situation rather than helping it. An example of a well-intentioned faux pas might be installing a power turbine to help “provide more outtake” in conjunction with your ridge vents. The problem is that air will now intake through the ridge vents, and outtake through your new power vent, effectively closing off the bulk of the attic air and making it stagnant. There’s a place for power turbines, but the point is, ventilation needs to be thoroughly understood before attempted.
In the photo below, the left picture shows installation of a shed roof vent where it ties into a two-story wall. The right picture shows a completed ridge vent.
Step Eight in the GAF Roofing Process – Installing Hip and Ridge Shingles
We mentioned earlier that the edges of your roof are a vulnerable place (the reason for installing starter strips correctly). Additionally, the hips and ridges of a roof experience the most wind, and need to have enhanced products. It is right here, however, that many roofers skimp. They cut up 3-tab shingles (rated for 60 mph or 80 mph) and use them on a roof with dimensional shingles that is supposed to be covered up to at least 110 (or even 130) mph! GAF Factory Certified roofers understand the importance of hip and ridge shingles, and utilize a specialty shingle, such as GAF’s TimberTex®, to protect these vulnerable places on your roof.
Not only do cap shingles like TimberTex® better protect your roof, they greatly enhance the overall look of your roof by accentuating the lines. One single, loose piece of TimberTex® is featured in the image below. Notice the double-ply thickness, and the large dimensions.
Step Nine of our GAF Roofing Process – Clean Up, Shingle Recycling, and Final Inspection
Once you get your roof installed, you want to make sure that the place gets cleaned up. We utilize a magnet to remove nails, and carefully go over the yard to remove small bits of debris. The torn-off shingles will go to a recycling facility to be turned into roadway, and we will make a final inspection of the roof.
Step Ten in the GAF Roofing Process – Delivering the System Plus Warranty
Last but not least is the warranty. We make sure the homeowner gets in their hand a printed copy of GAF’s limited lifetime System Plus warranty. Click to read more about this GAF warranty. It’s a lifetime manufacturer’s warranty that is non-prorated for the first 50 years, and is transferable to a second homeowner in the event of a sale within the first 20 years, provided a phone call is made to transfer ownership of the warranty at the time of the sale. A printed copy of a warranty, with an installer who has been careful to adhere to it’s “fine print,” means you have more than just someone’s word-of-mouth on it. We also provide a 5-year proper-installation warranty. If you need an estimate on your roof, please call us to schedule an appointment! You can contact the owner at (334) 332-7799.