Expanding foam is a versatile product used in construction and DIY projects for insulation, sealing, and filling gaps. It starts as a liquid, expands on contact with air, and quickly hardens into a durable, rigid material. Known for its excellent insulation properties, expanding foam is the perfect solution for sealing leaks, improving energy efficiency, and providing sound insulation.
In this article, we explain what expanding foam is, how it can be used, some of its benefits, and top tips for best practice.
Expanding foam is a handy construction and home maintenance product with multiple purposes. Typically made from polyurethane, expanding foam is dispensed from a pressurised can or gun applicator and consists of an isocyanate and a polyol resin which react when mixed. When exposed to air and moisture, the foam expands, filling gaps and hardening within minutes.
There are two main types of expanding foam, and the best option for you depends on what you’re using it for.
Open-cell foam: A softer option with more flexibility and great sound absorption
Closed-cell foam: Denser and more rigid than open-cell foam with excellent thermal insulation and moisture resistance properties
Expanding foam can be used in various ways thanks to its unrivalled versatility. Some of the most common uses of expanding foam include:
One of the main uses of expanding foam is insulating walls, floors, roofs, and cavities. Closed-cell spray foam is particularly effective at reducing heat loss, helping to lower energy bills and make homes more environmentally friendly.
Expanding foam is ideal for sealing around window and door frames, holes around pipes, and other hard-to-reach areas. It prevents draughts and stops heat from escaping which is particularly important during winter months.
Open-cell foam can be used to reduce noise from adjoining rooms or outside, making it useful in both residential and commercial properties.
Some types of closed-cell expanding foam are waterproof and offer excellent moisture resistance, making them suitable for sealing basements or external walls. Other expanding foams, including most open-cell options, offer some water resistance but won’t be as effective at fixing leaks.
Expanding foam boasts a wide range of benefits, including:
High R-value - Closed-cell foam has a high R-value, making it one of the most efficient heat insulation materials available.
Air and moisture barrier - It provides a reliable seal that keeps out water and air. Opt for a closed-cell option for a waterproof solution.
Quick and easy to use - The foam expands to fill spaces of all shapes, reducing the need for precise measuring or cutting
Long-lasting - Once set, expanding foam is durable and doesn’t degrade easily
Improved energy efficiency - By sealing gaps, expanding foam can help to reduce energy bills by improving the energy efficiency of the property
Follow our top tips for using expanding foam to ensure you complete your task to a high standard:
Expanding foam is able to insulate and seal making it ideal for construction projects and home maintenance. Through following best practice, expanding foam offers a quick, effective solution for a wide range of tasks.
If you’re looking for expanding foam for your project, take a look at our range and find the right option for you.