GOOD FAQs

Proper roof ventilation is vital for preserving the health of both your attic and your roofing material. When fresh air circulates through the attic space, it helps prevent moisture accumulation and excessive heat buildup—two factors that can trigger mold growth, foster deck rot, and reduce energy efficiency. Many asphalt shingle warranties also hinge on having a correctly ventilated roof deck, because trapped heat and moisture can hasten shingle deterioration. By ensuring a correct calculation of intake vents (often in the soffits or along eaves) and exhaust vents (like ridge, gable, or roof vents), you not only extend the lifespan of your roof but also keep your manufacturer warranties intact.

Ridge vents are elongated openings positioned along the roof’s peak. They typically work in tandem with soffit or eave vents to create a continuous airflow that flushes out hot, humid air from the attic. By allowing this stale air to escape, ridge vents help keep the underside of your roof cooler and drier, reducing the risk of mold or premature shingle failure. Still, ridge vents are just one type of exhaust vent—O’Hagin vents and gable vents are alternative options that can complement or replace them. The central goal, regardless of vent style, is to ensure your home has both adequate air intake (via soffits or eaves) and sufficient exhaust (ridge, O’Hagin, or gable vents) so that humidity and heat aren’t trapped inside the attic.

Even if you use a powered attic or whole house fan, passive vents (such as O’Hagin, ridge, or gable vents) remain an essential component of a balanced roof ventilation system. While fans can actively move air out of your attic, they still rely on adequate intake vents to supply fresh, cooler outside air. Moreover, if the fan fails for any reason, you would be left without a reliable means of ventilating the space unless a sufficient network of passive vents is in place. Without enough intake and exhaust vents, a powered fan could also create negative pressure in the attic, potentially drawing in moisture from undesired sources or running inefficiently. In short, powered fans and passive vents complement each other by providing both active circulation and a stable baseline of airflow—ensuring your attic remains properly ventilated, no matter the circumstances. 

 In California, building codes typically call for one square foot of net free vent area (NFVA) for every 150 square feet of attic space, although this can vary depending on your roof’s specifics. For a 1,500-square-foot attic, you would need about 10 square feet of total vent area to meet the 1:150 ratio. While a 50/50 split between intake (e.g., soffit vents) and exhaust (ridge or gable vents) is common, many professionals suggest using a 60/40 split to prioritize slightly more intake. Applied to this example, that would allocate approximately 6 square feet for intake and around 4 square feet for exhaust. Such a distribution encourages more consistent airflow, helps prevent negative pressure in the attic, and supports effective removal of heat and moisture—ultimately prolonging the life of your roof and safeguarding its structural integrity. 

Roof slope—essentially how steep your roof is—plays a major role in determining which materials and installation methods are appropriate. Each roofing product is rated for specific slope ranges. Placing a material designed for a steeper slope onto a low-slope roof often leads to leaks and can even void manufacturer warranties. Correctly matching the product to the slope protects your investment and helps your roof perform effectively over the long term.

Steep slope roofing refers to any system installed on roofs with a pitch of 3:12 or greater. The pitch measurement indicates how many inches the roof rises vertically over 12 horizontal inches. Steep slope roofs typically drain water quickly and support various materials. Common choices include asphalt shingles, clay and concrete tiles, wood shakes, slate, and metal panels.  

Even a so-called “flat” roof needs a slight pitch to facilitate proper drainage. If the roof surface is too level, water can collect in puddles (ponding), causing leaks, promoting algae or mold, and stressing the structural framework. To avoid these problems, roofers often use tapered insulation to create a subtle slope that guides water to drains or scuppers, thereby prolonging the life of the roof system.

Most high-quality asphalt shingles can remain in good working condition for about 20 to 30 years; however, several factors can shorten or extend that window. The grade of shingle, the quality of the initial installation, and your local climate all play significant roles, as does regular maintenance. It’s also worth noting that the roof section receiving the most direct sunlight—often the south- or west-facing slope—tends to age faster, resulting in visible wear or fading well before the less-exposed areas.

If your asphalt shingle roof has passed the 20-year mark—or if you see problems across wide areas such as rampant leaks, soft spots in the decking, or a large number of missing shingles—replacement usually makes more financial sense than continuous patching. A key warning sign is when the granular coating on the shingles wears away and reveals the shiny or fibrous base. Without those protective granules, shingles lose essential UV and moisture defense, which speeds up their deterioration.  

While California building codes allow for two shingle layers, industry professionals typically advise tearing off the old material before installing a new roof. Layering shingles can lock in extra heat, hastening the aging process of the top layer and potentially voiding your new shingle warranty. Removing the existing roofing also gives you the opportunity to inspect and repair the underlying deck and ensures a flatter, cleaner surface for the new underlayment and shingles—leading to a neater finish and a more reliable install in the long run.

TPO (Thermoplastic Polyolefin) is a single-ply roofing membrane designed primarily for flat or low-slope structures. Roofers and property owners value TPO for its robust heat-welded seams, impressive durability, and energy-efficient reflective surface. Unlike peel-and-stick membranes that depend on adhesives prone to degradation, TPO seams are hot-air welded into a single watertight layer. Its natural flexibility also helps it adjust to temperature shifts without cracking, ensuring consistent protection against leaks over time.

TPO Roof Flexibility
Thermoplastic roofs soften when heated and harden upon cooling, allowing the membrane to expand and contract with the building as temperatures fluctuate. In regions with significant day-to-night or seasonal shifts, this flexibility is invaluable—it prevents stresses on the roof surface that can lead to premature failures in more rigid materials.

  Value: TPO membranes deliver excellent performance at a competitive cost.

Strength & Durability: Hot-air welded seams, coupled with polyester reinforcement, make TPO resistant to tearing, punctures, and other impacts.

Energy Savings: The membrane’s white surface reflects sunlight, often resulting in lower cooling bills and reduced heat buildup.

Bioresistance: TPO naturally fends off fungi, bacteria, and debris, reducing maintenance needs.

Fire Resistance: Many TPO products carry a Class A fire rating, making them suitable for environments where fire safety is paramount.

A TPO roof can serve you for 15 to 25 years. The actual longevity hinges on membrane thickness, the quality of workmanship, and proper upkeep—particularly around flashings and drainage points—to prevent standing water and leaks.

TPO roofing systems are lightweight, adaptable, and suitable for a variety of building types and climates. Depending on your project’s requirements and timelines, one of the following approaches may be recommended:

Mechanically Attached

• The membrane is fastened directly to the decking using special plates and screws.
• Extra fasteners are often placed around edges and corners for protection against wind uplift.
• All seams are then hot-air welded for a dependable, watertight seal.

Induction Weld (Point-Affixed)

• A specialized plate is anchored to the roof deck, then the TPO membrane is bonded to this plate via electromagnetic induction.
• Afterward, the membrane seams are welded as usual to guarantee full waterproofing and superior performance in windy conditions.

Adhered

• The membrane is glued directly to the substrate—often insulation or another approved surface—using either an adhesive or low-rise foam.
• This uniform attachment distributes uplift forces more evenly, which can enhance both aesthetics and wind resistance.