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Is spray foam insulation worth it?

By: Kelly Bellerson

Spray foam is the most popular choice of insulation to date, but is it worth it?

According to RICS, if spray foam insulation is found during an inspection the value of the property will reduce and could even render your property un-mortgageable.

What is spray foam insulation?

For more than 30 years spray foam insulation has been used as an effective insulator with a track record of successful application in those hard-to-reach areas.

It’s a type of liquid insulation that can be broken down into two different types: closed cell spray foam, a solid thermal insulator, and open cell spray foam, the weaker of the two. Both must be applied by a specialist.

Once sprayed, the foam sets and expands with roofs, lofts, walls, floors, and more benefitting from its versatile insulation properties and high thermal performance.

Why is it used?

Spray foam isn’t as thick as other types of insulation. Many people often avoid insulating their roofs so they can use it for storage, but spray foam is at the right capacity to allow for both roof insulation and storage.

Additionally, it can be a good solution for buildings that are subject to planning restrictions where external insulation is prohibited.

There are certain types of spray foam that are waterproof, as well as breathable, which can be great for properties located in flood-prone areas.

How much does it cost?

Compared to other types of insulation such as polystyrene slabs, EPS, and glass-wool, spray foam is the more expensive option. It costs between £20 – £50 per square metre to have spray foam professionally installed.

The ECO Scheme is offered by some energy firms for eligible properties struggling to insulate their building. Grants that can cover the installation fees are also available in some circumstances.

Is my property suitable?

Most properties are suitable for spray foam insulation. If you are unsure, a building survey can indicate whether spray foam can be applied. Listed buildings and those with a thatched roof should NOT have it installed.

If your build has any defects, such as a leaking roof, spray foam can cause serious problems. Additionally, this type of insulation should not be used to cover any defects or be installed on top of partial/existing insulation.

Pros of spray foam insulation

Depending on your building’s needs, spray foam insulation is good for:

  • Hard-to-treat areas
  • Soundproofing
  • Thermal qualities
  • Versatile application
  • Sufficient insulation with storage room

Cons of spray foam insulation

However, there are a few elements to spray foam insulation that can be difficult to work with:

  • It’s expensive
  • Must be installed by professionals
  • Hard to remove after installation
  • Lack of ventilation
  • Can cause humidity, damp, and timber decay
  • Toxic fumes emitted during installation
  • Unattractive and messy – cannot be decorated over
  • Negatively affects the value of the property

How does it affect my property?

Ultimately, spray foam insulation can be problematic if you are buying or selling, as it is extremely difficult to remove and can cause more harm than good due to problems associated with condensation, ventilation, decay and other defects that can impact the quality and condition of the property

These issues decrease the building’s overall value, as subsequent works may be needed to correct these defects that can arise from having it installed.

According to The Royal Institution of Chartered Surveyors, a building can be deemed un-mortgageable if spray foam insulation is found at the property.


The decision to have spray foam installed comes down to preference, budget, and the property’s individual needs.

While this type of insulation has some rewarding benefits such as waterproofing, versatility, and exceptional thermal performance, it is often advised against.

Professionals, in most cases, do not recommend spray foam as a form of insulation in any type of commercial or residential build due to the vast number of problems it can cause.

Need advice? Speak to one of our friendly team members today!

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