Suspended Timber Floor Spray Foam Insulation

Suspended Timber Floor Spray Foam Insulation

Do you want to make cold floors a thing of the past? Do you want to eliminate draughts permanently? How about dramatically increasing the thermal quality of your home and save on energy? Spray foam insulation for your suspended timber floors can help you achieve all these objectives.

Typically, a 100–125 mm application on the underside of the floor deck would result in a reduction of 95% of heat flow and therefore enable the timber to breathe naturally through it.

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What is Suspended Floor Insulation ?

A suspended timber floor refers to floorboards that are mounted on top of timber joists. These are usually insulated from below, but if that can not be done, then it is still possible, in some situations, to insulate between the joists in the frame.

It’s also important to remember that spray foam provides the floor with structural support; a feature that proves invaluable in older houses.

How Does Suspended Timber Floor Spray Foam Insulation Work ?

Applying spray foam insulation to the underside of the floorboards will prevent convection air movement, thus keeping the necessary airflow below but not penetrating the room above.

Spray foam insulation is engineered for both thermal and breathable insulation. It will let you enjoy more comfortable temperatures and less need to use energy-consuming solutions such as heaters or boilers.

Why Insulate a Suspended Timber Floor ?

Heat loss through draughts in a very draughty home will potentially increase the heat loss from the building. Ground floor insulation is a perfect way to keep your property warm. Insulating a suspended timber floor will remove floor draughts, while at the same time reducing heat loss through the floor covering.

Generally speaking, the ground floor is the only floor that needs insulation. When you’re on an upper floor, your floor usually doesn’t need to be insulated. However, you should consider insulating upper floors above unheated spaces such as garages, as you could lose a lot of heat to those areas.

What’s the Cost of Floor Insulation on Average ?

Hiring a contractor to put spray foam insulation on a suspended timber floor will set you back a few hundred pounds. For a typical house, you’re looking at a price range of about £1,000 to £2000, but this price can differ based on the floor size, the thickness of the insulation, and whether the floor requires some repairs before installing the insulation.

Why Choose us ?

Ifspray is one of the leading installers of spray foam insulation in the UK. We are accredited and fully licensed to carry out spray foam insulation across the UK.

We cover the whole of the UK. Our accredited local spray foam installers have installed spray foam insulation for domestic and commercial clients in cities such as London, Liverpool, Southampton, Leeds, Sheffield, Cardiff, Coventry, Portsmouth, Sunderland, Aberdeen, Milton Keynes, Derby, Swindon, Leicester, York, Nottingham, Birmingham, and many more.

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Get in touch on 02380970979 to learn more about spray foam insulation or get an instant, free, no-obligation quote. Our professional and friendly customer service team will attend to you promptly.


Suspended timber floors are the finished wooden floorboards fixed to floor joists, which are suspended over the subfloor of the foundation. In small supportive columns, these floor joists are elevated above the subfloor, called tassel walls (or sleeper walls).

Unlike regular buildings on the ground level, the suspended floors do not lie directly on the ground. This allows for air passage and drainage to prevent mould and dry rot that would otherwise occur in wet ground. However, if not well insulated, this ventilation can cause draughts and cold air to rise into the rooms above.

Ideally, spray foam insulation works well with timber floors as it can soak up thermal energy and reduce the flow of air across the insulation and it is a better material for taking out draughts.

Insulating a suspended timber floor will reduce floor draughts, while at the same time reducing heat loss through the floor covering.

In uninsulated floors, you can lose as much as 10% of heat.

The best way to ventilate suspended timber floors is to place vents under the joists. This should also be done in walls facing each other. The vents need to be sealed in order to prevent dust from reaching the interior of the building.