Asphalt Shingle Roofs: What are they and what you should know.
/The roof on the house I purchased in 2023 was in desperate need of repair and last year I decided to try my hand at reroofing it. Through a lot of research, conversations and with the help of family and friends we were able to achieve a gorgeous new asphalt shingle roof.
When it comes to roofing materials, asphalt shingles have been a popular choice for decades, and for good reason. Not only are they cost-effective, but they also offer durability, versatility, and aesthetic appeal to complement any home. In this blog post, I share everything I know on asphalt shingle roofs, covering everything from the materials used to installation techniques, best practices, and dos and don’ts of maintenance.
Section 1: Asphalt Shingle Roof Materials
The following are the main building materials that one would expect to use for a new shingle roof:
1. Asphalt Shingles: Shingles are a composite roofing materials that consist of the following layers
Base Mat: The base mat is typically made from fiberglass, organic felt, or a combination of the two. Fiberglass offers superior strength and resistance to moisture, while organic felt provides a more traditional and slightly softer feel. The choice of base mat affects the overall durability and flexibility of the shingles.
Asphalt Coating: The base mat is coated with high-quality asphalt, which serves as a waterproofing agent. The asphalt also enhances the shingles' flexibility and ensures they can withstand extreme weather conditions, including heavy rain and wind.
Mineral Granules: The top layer of the asphalt shingle is covered with mineral granules, which not only add color and visual appeal but also protect the shingles from harmful ultraviolet (UV) rays. UV rays can degrade the asphalt over time, so these granules are vital for the shingles' longevity. It is crucial to select a product with low granule loss.
2. Underlayment: Underlayment is a crucial layer installed between the roof deck and shingles. Common underlayment materials include asphalt-saturated felt and synthetic materials. It provides an additional barrier against water infiltration and helps protect the roof deck from potential moisture damage.
3. Ice and Water Barrier: In regions prone to ice dams and heavy snowfall, installing an ice and water barrier is essential. This self-adhesive, waterproof membrane is applied at the eaves, around penetrations, and in valleys to prevent water from seeping into vulnerable areas. Fun fact, these barriers are also great to protect wooden joists on your next exterior deck project.
4. Flashings: Flashings are metal pieces used to waterproof roof transitions, such as around chimneys, vents, and skylights. Eaves and rake flashings are installed before and after underlayment, respectively, to direct water away from these vulnerable roof edges.
5. Gutters: A rain gutter or eavestrough is a trough/channel at the eaves to collect and direct rainwater away from the building’s foundation.
Source: Duraflo
6. Vents: Adequate ventilation is essential for any roofing system. Soffit venting allows cooler air to flow up through the soffits and as the heat warms up it travels into the top of the attic. Exhaust vents, like ridge vents or roof turbines, allow hot air and moisture to escape from the attic, reducing the risk of shingle damage and prolonging the roof's life. Recommended venting is 1 square foot of combined exhaust and intake vents for every 300sqft of attic floor.
7. Starter Strips: Starter strips are specially designed shingles used at the eaves and rakes. They have an adhesive backing that provides a strong seal and prevents wind uplift along the roof's edges.
8. Ridge Caps: Ridge caps are the shingles installed along the roof's peak to cover and protect this vulnerable area. Properly installed ridge caps enhance the roof's appearance and provide an additional layer of protection against wind and water.
Section 2: Asphalt Shingle Roof Installation Techniques and Best Practices
Proper installation is crucial to ensure the longevity and performance of your asphalt shingle roof. Here are some essential installation techniques and best practices:
Source: IKO
1. Eaves and Edge Flashings: Install eave flashings before applying the ice and water barrier or underlayment. Install rake flashings after installation of any ice and water barrier or underlayment. These metal flashings provide an extra layer of protection along the roof's edges, directing water away from vulnerable areas.
2. Ice and Water Barrier: Install the ice and water barrier at the eaves, around penetrations, and in valleys. This waterproof membrane prevents water infiltration in areas prone to ice dams and heavy snowfall.
3. Underlayment: Apply the underlayment to provide an additional layer of protection against water infiltration and protect the roof deck.
4. Starter Shingles: Begin the installation with starter shingles along the eaves and rakes. They provide a secure edge and prevent wind uplift.
5. Proper Nailing: Use the manufacturer's guidelines for the appropriate number of nails per shingle and their placement. Over or under-nailing can compromise the shingle's integrity and lead to premature damage.
6. Spacing: Check your vertical spacing every 5th or as recommended by the manufacturer to ensure a straight roof.
7. Ventilation: Ensure proper ventilation in the attic to prevent heat and moisture buildup, which can cause shingle deterioration and reduce the roof's lifespan. This includes soffit intake venting and exhaust venting near the ridge line.
8. Ridge Caps: Install ridge caps once the field shingles are in place. Ridge caps should be securely fastened and properly sealed to prevent water penetration at the roof's peak.
9. Gutters: Install the gutters onto the fascia with the back slid up and under the flashings. Gutters should slope towards the downspout with 1/2” drop every 10 ft. Downspouts should never drip onto another section of roof, instead the downspout should run to another gutter.
Section 3: Dos and Don'ts of Asphalt Shingle Roof Maintenance
Regular maintenance is essential to extend the life of your asphalt shingle roof and keep it looking its best. Here are some dos and don'ts:
Dos:
1. Inspect the roof regularly for damaged or missing shingles, and promptly address any issues to prevent water leaks.
2. Clean gutters and downspouts regularly to prevent clogs and water backup, which can damage the shingles and promote moisture-related problems.
3. Trim overhanging branches to prevent damage from falling debris and reduce the risk of moss and algae growth.
Don'ts:
1. Avoid pressure washing your asphalt shingle roof, as it can dislodge granules and damage the shingles.
2. Refrain from walking on the roof unless absolutely necessary, as foot traffic can cause unnecessary wear and tear on the shingles.
3. Do not ignore even minor issues with your roof. Timely repairs can prevent more extensive and costly damage in the future.
Conclusion
Asphalt shingle roofs offer an excellent roofing solution with a combination of affordability, durability, and aesthetic appeal. By understanding the materials, installation techniques, and maintenance best practices outlined in this guide, you can ensure your asphalt shingle roof serves you well for many years to come. Remember, regular maintenance and timely repairs are key to maximizing the lifespan and performance of your roof, so don't hesitate to take the necessary steps to keep it in top condition. If you have any concerns or require assistance, always consult with a professional roofing contractor to ensure the best results