What is Cavity Wall Injection Insulation?

If your home was built before the 1980s, chances are your exterior walls are missing a crucial element: wall cavity insulation. Adding insulation to cavity walls became common practice in the 1970s and was eventually mandated by most building codes in the 1990s. Uninsulated cavity walls lead to high energy bills, drafty rooms, and uncomfortable temperatures. But don’t worry – cavity wall injection insulation is here to save the day!

What is Cavity Wall Injection Insulation Exactly?

Cavity wall injection insulation is a modern solution for homes built with cavity walls, which are essentially two exterior walls with a hollow space between them, that don’t have wall cavity insulation. This gap, though intended for ventilation, often acts as a thermal bridge, allowing heat to escape during winter and enter during summer. Cavity wall injection insulation is created by combining a resin, a foaming agent, and water. This mixture has a shaving cream-like consistency that enables it to easily flow into every nook and cranny. This results in a more comfortable home with reduced energy consumption, ultimately leading to lower heating and cooling bills.

The Injection Process: Quick, Clean, and Effective

The process is surprisingly simple. Installation involves injecting foam insulation through small holes drilled in the exterior wall, ensuring minimal disruption and maintaining the aesthetic integrity of your home. Upon installation, injection foam insulation expands to completely fill the cavity, sealing all gaps and cracks, navigating around obstacles like wires and pipes within the wall cavity. Injection foam maintains its form and structure within the wall cavity, never settling, shifting, compressing, or sagging over time for optimal insulation. Proper injection insulation also ventilates, avoiding any mold or mildew growth. Here are the steps for installation: 

  1. Assessment: A professional will determine if your home is suitable for cavity wall injection insulation.
  2. Drilling: Small holes are drilled into the exterior walls.
  3. Injection: Insulation material (typically foam) is injected into the cavity.
  4. Sealing: The holes are sealed, leaving your walls looking as good as new.

Benefits of Cavity Wall Injection Insulation

Cavity wall injection insulation offers a range of advantages homeowners need to be aware of:

  • Reduced Energy Bills: By preventing heat loss, you’ll rely less on your heating and cooling systems, saving you money in the long run.
  • Thermal Performance: Provides the best thermal cavity wall performance for the lifetime of your home. 
  • Flood & Water Damage Prevention: Eliminates the risk of water damage and flooding in the exterior walls of your home, and is resistant to moisture accumulation.
  • Improved Comfort: Say goodbye to drafts and uneven temperatures. Your home will feel more comfortable year-round.
  • Increases Wall Stability: Increases wall stability, especially where wall ties are ageing and starting to fail.
  • Non-Fibrous: Referring to insulation materials that are not made of fibres, such as foam or bead injection insulation for better thermal protection and cleaner installation.
  • Eco-Friendly: Many insulation materials are made from recycled content and are environmentally friendly.
  • Quick and Easy Installation: The cavity injection process is minimally invasive and can usually be completed in a day.
  • Increased Home Value: Energy-efficient homes are more attractive to buyers.

Is Cavity Wall Injection Insulation Right for Your Home?

If your home was built with cavity walls and lacks insulation, then cavity wall injection is a fantastic option. It’s a cost-effective, eco-conscious solution that will transform your home into a cozy haven, saving you money on energy bills in the long run.

Remember: It’s crucial to have a professional assess your home and determine the best type of cavity wall injection insulation for your specific needs and home type.

Cavity injection wall insulation is a simple yet effective way to enhance your home’s energy efficiency, comfort, and overall value. By properly filling the empty spaces within your walls, you’re not just sealing in warmth – you’re investing in lower energy bills and comfort. With minimal disruption, a straightforward installation process, and long-lasting results, cavity wall injection insulation is a worthwhile investment for any homeowner seeking to make their home more comfortable and cost effective. 

If you’re ready to experience the benefits of a warmer, quieter, and more energy-efficient home, contact us today to explore your options and take the first step towards a more comfortable and protected home.


Q: How long does cavity wall injection insulation last?

Answer: When installed correctly, cavity wall insulation should last for the lifetime of your home.

Q: Will cavity wall injection insulation damage my home’s exterior?

Answer: The process is minimally invasive. The small drill holes are sealed after injection, leaving your walls virtually untouched.

Q: Is cavity wall injection insulation messy?

Answer: The installation process is generally very clean. Professionals take precautions to minimize dust and debris.