Akfix 805P PRO Gap Filler Expanding Foam Sealant - Low Expansion

In this review of the Akfix 805P PRO Gap Filler Expanding Foam Sealant, the bottom line is simple: this is a practical choice for installers and DIYers who need a reliable, low-expansion polyurethane foam that fills large gaps and provides durable thermal and acoustic insulation. The product stands out for its higher yield and gun-compatible application, making it well suited to window and door installation, wall cavities and other jobs that demand quick, continuous coverage. The UL classification and waterproof, paintable versions make it useful both inside and out.

Key Features

• Gun-compatible application: The can is designed to be used with an applicator gun so output can be regulated for cleaner, easier application on frames, gaps and joints.
• High yield: The single-component foam offers economical consumption with up to 45 litres yield depending on temperature and humidity, lowering material costs on larger jobs.
• Durable insulation: Once cured the rigid foam forms a continuous insulating layer that reduces thermal bridges and helps with sound insulation.
• Low expansion formula: The low expansion behaviour reduces the risk of excessive pressure around window and door frames while still filling irregular cavities well.
• Environmentally considered: The formulation contains no ozone-depleting propellant gases, which is beneficial for users concerned about environmental impact.

Who It's For

The Akfix 805P PRO is aimed at professional contractors and experienced DIYers who regularly install windows, doors or need to seal larger gaps and cavities. Its gun use and adjustable output suit users who prioritize control and a higher material yield on mid to large projects.

Users who need a ready-to-use squeeze canister or who require a foam specifically formulated for very high expansion or spray insulation of entire attics should look at other products; this one is optimized for low expansion, precise filling and gun application rather than blanket-spray insulation.

Pros & Cons

Pros

• Good spray quality with controllable output when used with an applicator gun, which reviewers noted flushes out well.
• Economical usage because of the high yield, so one can covers more gaps per can under typical conditions.
• Creates a solid, rigid insulating layer that helps with both thermal and sound insulation once cured.
• Does not use ozone-harming propellant gases, making it a more environmentally conscious choice.

Cons

• Gun is required but not included, so buyers must own or purchase an applicator gun separately to get the stated benefits.
• Performance can vary with temperature and humidity, so handling and storage require attention to the recommended ranges.

Specifications

Product name	805P PRO Gap Filler Expanding Foam Sealant
Package	12 x 24 oz cans (gun not included)
Foam type	Single-component polyurethane, low expansion
Colour	Light yellow
Yield	Up to 45 litres per can depending on conditions
Application temperature	28 F to 86 F (optimal can temp 68 F)
Certifications	UL classified

Our Verdict

The Akfix 805P PRO is a solid, cost-effective option for anyone needing a gun-applied, low expansion foam for window and door installation, gap filling and sound or thermal insulation. It delivers good spray quality, high yield and a durable cured foam, but shoppers should plan to use an applicator gun and follow the temperature guidance to get the best results.

Frequently Asked Questions

Do I need a gun to use this foam?
Yes, the 805P PRO is intended for use with an applicator gun; the can screws onto the gun and the gun lets you regulate output and reuse the can between applications.

Can this foam be used outdoors?
Yes, there are paintable and waterproof versions suitable for outdoor areas and water-exposed installations, making it appropriate for exterior window and door sealing when finished correctly.

How should I store and handle the cans?
Keep cans at recommended temperatures, shake well before use, and always apply with the can upside down; fresh foam is removable with the manufacturer suggested cleaner.