New Roof Installation In San Antonio | The 9-Step Process From Estimate To Cleanup

Every professional roof replacement starts with a proper inspection and a written estimate. This is not a formality. The inspection is where a qualified contractor assesses the condition of your existing roof, your decking, your ventilation system, your flashings, and any code requirements specific to your Bexar County property. The estimate that comes from that inspection should itemize materials, labor, disposal, and any identified repair work to the decking or flashing that will be needed once tear-off is complete.

What a proper estimate covers: Square footage of the roof, number of layers currently on the deck, decking condition, ventilation adequacy, flashing condition at all penetrations, and the full material specification including shingle brand, underlayment type, ridge vent or box vent plan, and drip edge requirements.

What should raise a red flag: A contractor who quotes your roof without getting on it, a quote that arrives within minutes of the first phone call, or a price that is significantly below every other bid you received. Low bids typically mean skipped steps or inferior materials.

Physical roof walk: No legitimate quote skips this Written scope: Every material and task itemized Decking condition: Assessed before tear-off is quoted Ventilation plan: Confirmed during the inspection

After you sign the contract and pay the deposit, two things happen before the installation crew sets foot on your roof: the permit is pulled with the City of San Antonio or Bexar County, and materials are ordered and delivered. Most roofing material deliveries in San Antonio are handled by a supply house that delivers directly to your property and uses a boom truck to load the shingles onto the roof itself. This keeps heavy pallets off your yard and positions materials close to where they will be installed.

Material staging on the roof is standard practice, but it needs to be done correctly. Shingle pallets placed on a roof that is about to be torn off add significant weight. A reputable crew accounts for this in how they plan the tear-off sequence so the decking is never overloaded. If you see materials stacked heavily over one section of an older home, it is appropriate to ask the crew lead about the load plan.

Tear-off is the process of removing all existing roofing material down to the bare wood decking. On most San Antonio residential roofs, this means pulling off the old asphalt shingles, the underlayment, and any existing drip edge. A proper tear-off exposes the full decking surface so the crew can inspect every board for rot, soft spots, delamination, and damage before anything new goes on top.

Some contractors offer a layover installation, also called a re-roof, where new shingles are installed directly over the existing layer without removing it first. While this is permitted under certain conditions in the building code, it is rarely the right choice for San Antonio homes. The Texas heat trapped beneath two layers of shingles accelerates the aging of both layers, voids most manufacturer warranties, and makes it impossible to inspect or repair the decking underneath. When we install a new roof, we always recommend a full tear-off.

How long tear-off takes: On a standard San Antonio residential roof of 1,500 to 2,500 square feet, a crew of four to six can complete tear-off in three to five hours. Steeper pitches, multiple layers, and difficult access take longer. Tear-off and new installation are often completed in the same day on a straightforward ranch-style home.

What the crew is looking for during tear-off: Rotted or delaminated OSB or plywood decking, wet insulation in the sheathing, improper flashing installation from the previous job, and any areas where the roof structure shows signs of sagging or damage.

Once the old roofing material is stripped away, the crew has full access to the decking for the first time. This is one of the most important moments in the entire installation. The decking is the structural layer that everything else is attached to. New shingles nailed into rotted or delaminated OSB will not hold. Fasteners that miss solid wood or pull through soft sheathing create immediate leak points.

Decking problems are common on San Antonio homes, particularly around chimneys, skylights, plumbing vents, and anywhere a previous roof had a leak that was not addressed promptly. Even a slow, minor leak that went undetected for a season or two can saturate and weaken the sheathing boards beneath. A professional crew will walk the entire deck surface after tear-off, pressing on boards to check for softness and looking for discoloration or mold that signals moisture damage.

Underlayment is the layer of material installed directly on the decking before the shingles go on. It serves as a secondary water barrier the defense layer that stands between your home and the elements if a shingle is ever damaged, blown off, or fails prematurely. In San Antonio, where severe thunderstorms can strip shingles and where summer heat accelerates material aging, quality underlayment is not optional.

There are three main underlayment types used in residential roofing: felt paper (15-lb or 30-lb asphalt felt), synthetic underlayment, and self-adhering ice and water shield membrane. Most San Antonio residential installations use a synthetic underlayment across the field of the roof, with ice and water shield applied in the vulnerable zones at eaves, in valleys, and around all penetrations.

Underlayment is installed starting at the eaves and working up the roof, with each row lapping over the one below by a minimum of 4 to 6 inches. Valley areas where two roof slopes meet get double coverage with ice and water shield self-adhered directly to the decking. Penetrations such as pipe boots, chimney bases, and skylight curbs are wrapped and sealed before the shingles cover them.

Drip edge and flashing are the metal components that direct water away from vulnerable points on your roof. They are not glamorous, they are not visible from the street after the shingles go on, and they are the single most common source of roof leaks in San Antonio. Flashing done right keeps water out for the life of the roof. Flashing done wrong or skipped entirely creates the conditions for persistent, hard-to-trace leaks that often do not appear until the second or third rainy season.

Drip edge: A metal strip installed along the eaves and rake edges of the roof. It hangs over the fascia and directs water into the gutter rather than allowing it to wick back under the shingles or run down the fascia board. Drip edge is installed at the eaves before the underlayment and at the rakes after the underlayment. On a proper installation, the sequence is never reversed.

Step flashing: Installed at every vertical wall intersection where the roof meets a dormer wall, an addition, or any vertical surface. Each piece of step flashing is interwoven with the shingles as they are installed, with one piece per shingle course. Step flashing cannot be applied after the shingles are already on.

Chimney and skylight flashing: Full base and counter-flashing systems that seal the transition between the roofing surface and the masonry or framed curb. Counter-flashing is embedded into the masonry mortar on chimneys and covered with a bead of roofing sealant.

Shingle installation is what most homeowners think of when they picture a roof replacement, and it is genuinely impressive to watch an experienced crew lay courses quickly and accurately. But the speed of a skilled crew can also make it difficult for a homeowner to evaluate whether the installation is meeting manufacturer specifications. The details that determine the long-term performance of your new roof are the nailing pattern, the nail placement, the course alignment, and the starter strip installation at the eaves.

Every shingle manufacturer specifies a nailing pattern for their products. For most standard three-tab and architectural shingles, that means four nails per shingle placed within a defined nail zone on the shingle body. Nails placed too high above the nail zone are called "high nails" and represent one of the most common installation errors in the industry. A high-nailed shingle is not properly secured to the roof and is significantly more likely to be blown off during a San Antonio wind event.

The starter course is the first row of shingles installed at the eave, and it plays a critical role in sealing the bottom edge of the roof. Proper starter strips are designed with a sealant strip that bonds the first full course of shingles to the roof surface. This is the point on the roof most exposed to wind lift. Without a properly installed starter course, wind can get under the bottom edge of the first shingle row and begin peeling the roof apart from the eave up.

Once the field shingles are complete, the crew finishes the ridge the highest point on the roof where the two opposing slopes meet. Ridge cap shingles are designed specifically for this purpose, with thicker body material and a pre-bent profile that conforms to the roof angle. They are nailed through both sides of the cap into the decking below and are the most exposed shingles on the entire roof, taking the full force of wind from any direction.

Alongside the ridge cap, the ventilation system for the roof is finalized at this stage. San Antonio homes require adequate exhaust ventilation at the ridge or eaves and intake ventilation at the soffit to create a continuous airflow path through the attic. Without proper ventilation, attic heat builds to the point where it cooks the shingles from the underside and dramatically shortens their effective lifespan.

Ridge cap options: Three-tab shingles cut into thirds and bent over the ridge (older method) or purpose-built hip and ridge cap shingles, which provide better coverage and a cleaner visual line. Most manufacturers require their own ridge cap product to maintain the full shingle warranty.

Ventilation options: Ridge vent is the preferred exhaust ventilation for San Antonio homes because it provides continuous ventilation along the full length of the ridge rather than relying on individual box vents placed at intervals. Ridge vents require corresponding soffit ventilation to function correctly.

Other finish details: All pipe boots sealed with a compatible sealant, all exposed nail heads on rake and starter edges covered, and any vent stacks trimmed and re-secured through the new roof surface.

The final stage of a professional roof installation covers three distinct activities: a thorough cleanup of the property, a final inspection of the completed work, and the delivery of your warranty documentation. All three matter, and none of them should be abbreviated.

Cleanup on a roofing job is more involved than most homeowners expect. Roofing debris torn-off shingles, old underlayment, spent nails, metal scraps from flashing work falls around the entire perimeter of the home during the project. A professional crew uses tarps to catch as much debris as possible during tear-off and loads it continuously into the dumpster throughout the day. At the end of the job, a thorough raking of the perimeter and a magnetic nail sweep of the lawn, driveway, and any paved areas around the home should be standard.

The final inspection should include a walk-through of the completed roof with the crew lead or project supervisor. Look for consistent shingle alignment, clean ridge cap installation, all penetrations properly sealed, and gutters clear of debris. After the city or county inspector signs off on the permit, you should receive your workmanship warranty document from the contractor and your manufacturer warranty registration if the installer is a certified contractor for that shingle brand.