F-13 vs. F-26: Which One’s Right for Your Job?
When it comes to high-strength, reliable construction adhesives, Leech Adhesives has been the trusted name since 1930. We proudly offer two top solvent-based construction glues: F-26 and F-13.
While both adhesives are weatherproof and popular go-to choices for construction projects, their chemical compositions and specific application strengths differ significantly. Choosing the wrong one could negatively impact the overall integrity and longevity of your project.
With that in mind, the team at Leech Adhesive wants to help you understand the key differences between Leech F-26® and Leech F-13® to help you select the right adhesive needed for your next construction project.
F-26: The Premier Heavy-Duty Workhorse
Our Leech F-26® Premium Quality Waterproof Construction Adhesive is recognized for its high strength and durability in demanding applications. F-26 is a premium, multi-purpose adhesive chosen for maximum structural bonding and permanence in challenging conditions.
F-26 Key Applications
F-26 is best suited for high-stress, permanent installations such as:
- Subfloors: Frequently used to eliminate floor squeaks by permanently bonding plywood to wood joists.
- Metal to Porous Substrates: Suitable for securing metal stud walls, stair treads, door saddles, metal moldings, and electrical outlet boxes.
- Heavy Construction: Bonds fiberglass, fiberboard, and treated lumber, especially in moist or challenging environments.
- General Exterior Work: Provides maximum strength and moisture-proofing in outdoor applications where these properties are required.
F-26 Pros
- Unrivaled Strength and Durability: F-26 is described as the “most powerful” and “longest lasting” construction adhesive in the industry, continuing to strengthen and stay flexible over time.
- Superior Waterproofing: This product is genuinely waterproof, making it excellent for outdoor construction and highly moisture-prone areas.
- Extreme Temperature Tolerance: It is designed to withstand extreme climates, operating within application temperatures ranging from 0°F to 120°F and surviving service temperatures from -20°F to 150°F.
- Gap-Filling: The thick mastic fills gaps, irregularities, and voids in materials, ensuring a solid, continuous bond surface.
- Momentary Pressure Hold: Parts are held in place with only momentary pressure, achieving a fast hold that saves time on bracing.
F-26 Cons
- Solvent Content: Like many high-performance adhesives, it is solvent-based and requires proper ventilation.
- Not Foam-Friendly: The powerful solvents in F-26 are typically too aggressive for sensitive materials like polystyrene foam insulation, which leads us directly to the F-13.
- Higher Cost: Due to its premium formulation and exceptional performance metrics, F-26 typically comes at a higher price point than general-purpose glues.
F-13: The Versatile Foam and Finish Specialist
Meanwhile, our Leech F-13® High Quality Construction Adhesive is a highly versatile, interior/exterior construction glue designed to solve a variety of construction projects, particularly those involving more sensitive or finished materials. While F-26’s main perk is strength, F-13 is about targeted versatility and flexibility.
F-13: Key Applications
Selecting F-13 is the best option when working on the following construction projects:
- Polystyrene Foam: Insulation (like polystyrene foam) and panels
- Tub Surrounds: Installing plastic and fiberglass tub enclosures and surrounds.
- Finishing Materials: paneling, drywall, ceramic tile, and general home construction and remodeling.
F-13 Pros
- Polystyrene Foam Compatibility: The essential feature. It allows you to adhere foam insulation to most building materials safely.
- Excellent Working Time: Offers a substantial 10-20 minute working time, allowing for precise placement, alignment, and adjustments of materials like large panels or tub surrounds.
- Ductile and Flexible: The formula stays ductile and flexible with age, preventing brittleness and providing a solid yet movable bond that can accommodate movement in building materials over time.
- Effective in Cooler Temps: Works well in colder environments, with an application temperature range starting at 0°F.
- Water Resistance: It provides excellent water resistance, suitable for wet areas like tub surrounds and exterior paneling (although not for continuous submersion).
F-13 Cons
- Flammable: F-13 is classified as EXTREMELY FLAMMABLE with a low flash point (<0°F) and requires positive cross-ventilation during use.
- Temperature Restrictions on Foam: It is crucial not to apply F-13 to polystyrene foam if the temperature is 90°F or higher, as the solvent action may become too aggressive.
- Water Immersion: It is not designed for continuous submersion. If your job requires the absolute highest degree of waterproofing and submerged performance, stick with F-26.
- Slow Drying: The working time is long, which means a full cure can take up to 24 hours, requiring temporary bracing.
Side by Side Comparison: F-13 vs. F-26
| Feature | Leech F-26® (The Workhorse) | Leech F-13® (The Specialist) |
| Primary Strength | Ultimate Structural Strength, Climate Tolerance | Polystyrene Foam Compatibility, Versatility |
| Foam Safe | NO (Solvents attack foam) | YES (Designed for polystyrene) |
| Water Performance | Waterproof (Suitable for tough conditions) | Water-Resistant (Not for continuous submersion) |
| Extreme Climate | Superior performance in extreme heat/cold. | Good, but limited foam application above 90°F. |
| Working Time | Fast hold, quick tack (Momentary pressure) | 10-20 Minutes (Allows for adjustments) |
| Flammability | Lower risk/higher flash point (Varies by product batch) | Extremely Flammable (Low flash point, requires extreme caution) |
| Key Uses | Subfloors, Treated Lumber, Metal Studs | Foam Insulation, Tub Surrounds, Paneling, Drywall |
Which Adhesive is Right for Your Construction Project Per the Leech Adhesive Experts:
Select F-26 For Your Construction Project When:
- You are bonding structural pieces such as subflooring or load-bearing wall studs.
- You are working with treated or wet lumber, especially in colder climates.
- Your construction projects require heavy-duty strength and a waterproof bond, such as exterior decks or structural elements exposed to the weather.
Select F-13 For Your Construction Project When:
- Your project involves polystyrene foam insulation (like rigid foam sheets on foundation walls or siding).
- You are installing a plastic or fiberglass tub enclosure/surround.
- You need a longer working time to align large pieces of paneling or intricate finishes.
- You are working on non-structural interior finishes that require a flexible, non-brittle bond.
F-13 and F-26 From Leech Adhesives
Ultimately, both the F-13 and F-26 from Leech Adhesives represent decades of commitment to quality, offering contractors reliable solutions for diverse job site needs. By understanding the main differences, you can ensure your adhesive choice will provide you with the best construction project outcome.
Have more questions about F-13 and F-26 products? Then contact our Leech Adhesive team today to learn more and set you on the right path for your next construction project!
