Skip to main content

Spray foam insulation vs traditional insulation

6 Dec 2022

Insulation is the barrier homes need to stop heat from escaping through walls, ceilings and lofts. However, in the UK many homes have inadequate insulation in place. According to EDF, just 58% of homes in England and Wales meet the insulation standards of 1976 or earlier.

The UK government is under pressure to reduce carbon emissions. They want to encourage homeowners to insulate their homes to minimise the impact of energy loss. For that reason, through the Energy Company Obligation (ECO), some energy companies offer free loft and cavity wall insulation to homeowners.

For homeowners, choosing the right type of insulation can be difficult with the various options on the market. Many people aren’t aware of the various options available and their benefits, including the choice of spray foam insulation. Read on below to find out about spray foam and how it compares against traditional insulation.


Spray foam insulation

Spray foam is an excellent choice for home insulation. Open-cell spray foam is sprayed as a liquid and expanding to over 100 times its original size when installed into lofts, walls and cavities. This allows it to be flexible enough to cover every gap and secure enough to create a superior air barrier that reduces thermal loss through convection and conduction.

This type of insulation is compatible with wood and timber. When applied by an authorised installer, it is vapour permeable and prevents moisture from outside of the property entering the roof. At the same time, spray foam insulation allows moisture from within the property to move freely through it and escape naturally.

Spray foam insulation features a superior R-value - the value that shows how good a material is at resisting the conductive flow of heat. The higher the R-value, the better - and spray foam insulation can provide that. The R-value of traditional insulation can be compromised before it is installed as it sits waiting to be installed. Conversely, spray foam doesn’t because it is made on site.

The process for applying spray foam is fast and safe. A team of professional and trained installers can finish the job in hours rather than days, causing minimal disruption to homes. Once set, it never sags or shifts - even in extreme temperatures.

There are two types of spray foam insulation: closed-cell and open-cell. While both share the same effective insulative properties, open-cell spray foam is usually the product recommended for homeowners in the UK.

While spray foam insulation is more expensive upfront than traditional alternatives, a study led by RGU’s Scott Sutherland School of Architecture and Built Environment, Heriot-Watt University and Icynene (now known as Huntsman Building Solutions) in September 2018, shows homeowners can save up to 56% on their heating bills. For those worried about rising heating bills, spray foam insulation is the best long-term choice. It's an investment in a more comfortable and energy efficient home that will pay for itself over time.

You can find out more in our what you need to know about spray foam blog.


Spray foam insulation vs fibreglass

Fibreglass is the most common and well-known method of insulation. Developed as an alternative to the harmful asbestos in the 1930s, fibreglass is cheap and fireproof. It’s available in two forms: long rolls or batt blankets.

While fibreglass is a quick and easy solution that can be rolled out and installed by homeowners and installers alike, there are downsides. Over time, fibreglass slumps or shrinks as gravity takes hold. This reduces its ability to insulate homes effectively. Spray foam meanwhile, stays set after installation.

When fibreglass is not installed properly or has been kept outside before installation, it can become wet. Once wet, fibreglass loses all its insulative properties and must be replaced before mould sets in. For that reason, it must be laid with a vapour barrier to prevent moisture build-up.

Batt blankets can be difficult to install into smaller or awkward places. This creates gaps making it less effective. It will eventually sag when used inside walls or on rafters. Eventually, it will collapse, creating more places for air to penetrate. It’s these gaps you won’t find appearing with spray foam as it can cover all the spaces where it is installed.

Lastly, for fibreglass to get a suitable R-value it needs a thickness of at least 270mm in an average loft. This makes it difficult to lay a floor in the loft or maintain head height.


Spray foam insulation vs wool insulation

Wool insulation is a popular choice for eco-conscious homeowners because it’s made from recyclable materials. Versatile and breathable, it can insulate every part of a home with good thermal and noise insulation. In the same way as fibreglass, mineral wool is available as loose fill or batts.

There are a few negatives that make wool insulation a less than an ideal choice for homes. Despite being made from raw materials, the insulation isn’t biodegradable, reducing its environmental benefits significantly.

Mineral wool insulation is also one of the most expensive types of insulation on the market, because of its heavy and hard-to-cut dense properties. Installation of wool insulation can take a long time and requires more labour, causing more expense to homeowners. With spray foam insulation, professional installers can complete the job in hours, not days.


Spray foam insulation vs PU board

PU board is a rigid polyurethane foam board, most suitable for new builds or dormer extensions than renovations or retrofits. The big difference for homeowners is down to the method of installation which can add significant costs to projects and is incredibly time-consuming.

To make PU boarding work, it has to be cut accurately to fit the spaces between rafters and ceiling joists. To reduce the risk of heat escaping through remaining gaps, the space must be filled with caulk or expanding foam. Someone should then seal every gap with foil tape for maximum efficiency.

Spray foam insulation removes all this effort and time consumption. Authorised installers can have it installed within hours and without complication.

Spray foam insulation is the superior choice for homeowners today. While it has a larger upfront investment, the long-term benefits and savings outweigh the initial spend. With fast application and a superior level of insulation than traditional insulation, spray foam delivers superior and reliable performance for decades to come.

Get a quote from a HBS authorised installer today with Huntsman Building Solutions or call us at +44 1485 500 668.