Installing or repairing a roof can be a big project. One of the most critical parts is selecting the suitable adhesive to attach your shingles—the adhesive bonds the shingles to the roof deck, creating a waterproof barrier. With so many options on the market, knowing which roofing adhesive is best for your specific needs can be tricky.
This comprehensive guide will walk you through the key factors to consider when selecting a roof shingle adhesive. I’ll compare adhesive types, discuss critical performance features, and provide application tips. By the end, you’ll have the knowledge to choose the ideal adhesive for your roofing project confidently.
Roof Shingle Adhesive Types
There are three main categories of roof shingle adhesive to choose from:
Asphalt/Bitumen-Based Adhesives
Asphalt or bitumen-based adhesives are the most traditional type used for shingle bonding. They utilize asphalt, a petroleum-based product, as the primary ingredient. Some key things to know:
- Offers a robust and durable bond in a range of temperatures. It can handle some movement of the roof deck.
- They are typically applied using a caulking gun or trowel. Comes in tubes or buckets.
- It is the most cost-effective option, suitable for projects on a tight budget.
- Messier than synthetic adhesives during application. Requires solvent for cleanup.
Popular asphalt-based adhesives include Henry 208R, Loctite Power Grab, and OSI Quad Max.
Synthetic Adhesives
Synthetic adhesives use polymers, urethanes, and other synthetic materials as the main components versus asphalt. Benefits include:
- Bonds well even in cold weather. Less temperature sensitive.
- It is easier to clean with just soap and water. No chemical solvents.
- Allows fast shingle application, reducing labor time.
- More expensive than asphalt adhesives. Cost can add up for larger roofs.
Leading brands of synthetic shingle adhesive are Liquid Nails Shingle & Roof, Loctite PL Premium Polyurethane Roof & Flashing, and NP1 Roof & Gutter Sealant.
Peel-and-Stick Adhesive Strips
Peel-and-stick self-adhering strips offer the most accessible, most hassle-free application. Benefits include:
- No caulking gun or trowel is needed. Just peel off the backing and stick.
- Clean look with no squeeze-out. Neater finished appearance.
- Allows fast shingle installation, reducing labor.
- More costly than liquid adhesives. Contractors may add a premium.
- Temperature sensitive. Best performance above 50°F.
The top peel-and-stick products are Grace Ice & Water Shield HT, Malarkey SecureStart, and Owens Corning Deck Defense High Temperature.
Key Features to Evaluate
Once you’ve decided on an adhesive type, there are several performance factors to take into account:
Bond Strength
The most important feature is the strength of the adhesive bond. A robust bond prevents shingles from loosening, lifting, or blowing away. Look for products that advertise “flexible” or “high-strength” bonds. These hold up better to roof movement and expansion/contraction.
Field testing data, like ASTM D903 wind resistance testing, can verify superior resistance to wind and weather. Larger bead sizes (1/4″+) also improve adhesion.
Temperature Resistance
Consider the range of temperatures the adhesive can effectively bond in. Asphalt adhesives typically perform better across high and low temps. Synthetic and peel-and-stick adhesives have more limitations in colder weather.
If installing in extreme climates, look for cold-weather, all-temperature, or “arctic grade” formulations. Some work in temps down to 0°F or below.
Waterproofing Ability
The adhesive should create a water-tight seal to prevent leaks. Look for products marketed as “waterproofing sealants” designed to block moisture. A thicker consistency is best for water resistance.
For peel-and-stick adhesives, the backing sheet acts as the first waterproof layer. This gives added leak protection underneath shingles.
Ease of Application
Consider how easily the adhesive can be applied, which affects labor time. Caulk-style adhesives take more time to spread evenly. Peel-and-stick strips are the quickest to install.
Some adhesives offer more comprehensive application temperature ranges that can be used year-round. Others feature non-stick surfaces that won’t gum up trowels or caulk guns during application.
Cleanup and Solvents
Asphalt adhesives require mineral spirits or other solvents to clean tools and hands, which some want to avoid. Synthetic adhesives and peel-and-stick strips can be cleaned with soap and water.
Cost and Value
Finally, compare the cost versus performance. Asphalt adhesives give the most economical solution overall. Synthetic adhesives cost a bit more but have added benefits like easier cleaning. Peel-and-stick strips are the most expensive yet offer the fastest, most straightforward application.
Application Tips and Techniques
Proper application technique is critical for the adhesive to perform as intended. Follow these best practices:
- Only apply in dry conditions when the roof is entirely free of moisture and dirt.
- Use a caulk gun or trowel to spread evenly across the shingle back or roof deck for liquid adhesives. Follow the coverage rate recommendations.
- Apply in vertical strips or an “S” wave pattern for optimal adhesion. Don’t just dot on spots.
- Use extra adhesive in high-wind zones, valleys, and low-slope areas. These see the most stress.
- Adhere to the manufacturer’s open times for assembly. Most adhesives tack up quickly.
- Set shingles gently into place; don’t press down hard initially. This avoids squeeze-out.
- Weight down freshly installed shingles if needed to ensure complete contact while curing.
- Follow any specific cleaning and disposal instructions for adhesives carefully.
FAQs
How much adhesive is needed for a typical roof?
Figure around 1-2 tubes or cans per roofing square (100 square feet) for liquid-applied adhesives. Peel-and-stick sheets come in set sizes to cover desired areas. Always buy at least 10% extra to be safe.
Should adhesive be used in all circumstances?
Adhesive is strongly recommended for sloped asphalt shingle roofs to prevent blow-offs and leaks. The only exception is using nails alone in warm climates on low slopes under a 4:12 pitch.
Does the roof deck require any preparation before applying adhesive?
Ensure the deck is clean, dry, and structurally sound. Sweeping and air blowing removes dirt and debris. Priming is usually unnecessary. Consult adhesive specifications.
How long does the adhesive take to cure fully?
Most adhesives become water resistant within a few hours but take 24-72 hours to cure fully, depending on temperature and humidity. Avoid heavy traffic during this period.
Is leftover adhesive reusable for later repairs?
Opened liquid adhesive must be used up fairly quickly before drying out. Unopened products may last 2-3 years if stored properly. Peel-and-stick sheets expire rapidly after opening.
Conclusion
Asphalt-based adhesives offer time-tested, economical performance. Synthetic adhesives provide excellent adhesion and easier cleanup. Peel-and-stick sheets simplify application greatly. To ensure efficient and secure installation, understanding how to use a roofing nailer is crucial in the roofing process. Weighing these factors will guide your roof shingle adhesive selection, helping you choose the most suitable adhesive for your particular roofing needs, ultimately enhancing the longevity and stability of your roof.
Proper application techniques ensure the adhesive performs as intended. Spread evenly across shingle backs using the recommended rate. Use extra in high-stress areas. Allow the right open and cure times before exposing it to foot traffic or weather. Follow all manufacturer instructions closely.
