Spray Foam For Under Floors
About Spray Foam For Underfloor Voids
Cold draughts and a lack of insulation generally make ground floors very cold and unbearable during winter months.
Either Sucraseal Open Cell or Nexseal LE Closed Cell are viable spray foam solutions to insulate the underside of the suspended floor system. The airtight insulation will stop draughts rising through the floor whilst mitigating heat loss from inside the house.
Draughts
Spray Foam will eliminate cold draughts entering your home
Thermal
Spray Foam has excellent thermal performance per inch
Eco-Friendly
Spray Foam uses recycled plastics with no harmful VOC’s or HFC’s
Draughts
Spray Foam will eliminate cold draughts entering your home
Thermal
Spray Foam has excellent thermal performance per inch
Eco-Friendly
Spray Foam uses recycled plastics with no harmful VOC’s or HFC’s
Where To Use Spray Foam For Floors/Under floors
Unlike pre-manufactured materials which are difficult to transport into an underfloor crawlspace and fix into place, spray foam offers the perfect solution. Spray-applied directly to the underside of the sub-floor deck, between joists, spray foam will adhere to the surface meaning that no mechanical fixings are required. The seamless, airtight and monolithic structure of spray foam helps to completely eliminate cold draughts whilst retaining the heat within the property. Both Sucraseal or Nexseal LE are suitable for under floors of all shapes and sizes. The process involves sending an installer into the underfloor void or where access is particularly tight, a Q-bot could be considered.
Retrofit Underfloor Voids
Underfloor crawl spaces are common in UK homes, particularly older Victorian style properties. With dense, cold air lingering low during winter, floor voids can become very cold a draughty. Spray Foam insulation provides an airtight thermal seal to stop cold air flowing into the home.
Commercial Projects
We’ve come across many large scale commercial projects where a tight underfloor void creates difficulties when insulating using traditional materials. The gravity defying nature of spray foam insulation helps to make it a permanent solution, using airtight materials manufactured in situ.
New Build Construction
In new build properties, it’s common for PIR insulation sheets to be laid on top of a concrete slab before underfloor heating is laid and the floor screeded. Nexseal high density closed cell foam offers perfect adhesion and an airtight seal of the concrete slab and can be screeded over.
What Our Clients Say
Trusted By
We’re proud to work with a range of clients across many industry sectors.
How We Help You
Enquire
Get in touch today to get the ball rolling
Specify
Let us specify the requirements for your project
Pricing
We’ll provide you with a budget price range
Install
Use one of our ThermoFoam-approved installers
Warranty
Once installed, we provide a 25-Year Product Warranty
Gallery
Check out our Gallery where you will find some photographs of installations we’ve completed in the past. Whilst spray foam is insulation and not decoration, our experienced installation teams will always endeavour to provide a neat and tidy finish to the insulation. Nexseal LE closed cell is easier to achieve a neater finish whereas Sucraseal Open Cell expands at a faster rate to leave an undulated finish.
FAQs
During winter months, dense, cold air tends to linger at floor level and can make for a very cold space. With underfloor voids generally ventilated via air bricks, cold draughts can then be pushed up through the floor, requiring additional heating to combat the impact. Spray foam insulation can be applied to the underside of the floor in crawl spaces.
This is not a recommended practice because the insulation can allow damp to track up from the ground which in turn could hold moisture and rot the floor deck. It’s also important to maintain the cross flow of air so that moisture can escape. The airflow is created by air bricks that are intermittently located under the damp course in the lower walls.
Pre-manufactured insulation materials can shrink, slip and degrade, especially with gravitational pull. Spray foam is entirely different because it is manufactured in-situ, therefore spray applied to the underside of the floor deck. The spray foam itself remains in an inert, unchangeable state once applied and it will therefore last with the life of your property.
We tend to send installers into the floor void crawl space as this represents the best chance of getting a monolithic airtight coverage of insulation. A general rule of thumb requires a minimum of 450mm clearance from the bottom of a floor joist to the ground in order for an installer to manoeuvre underneath the floor.
Provided there is pre-made access to the underfloor crawlspace, the process is usually carried out within a day for up to 150m2. The tighter the space, the longer it will take an installer to move about underneath the floor. A team of two is usually always present when underfloor voids are insulated due to health and safety reasons.
Under floor voids are generally well vented through ventilated blocks which promotes airflow under the floor. An installation of spray foam should not heighten any damp issues provided cross-floor ventilation is present. We run hygrothermal assessments on every project to ensure that the insulation design will perform adequately and without causing damage to the underfloor structure.
Our Products
Check out our BBA Certified Spray Foams
Our range of open and closed cell spray foams are industry-leading, BBA-Certified, use recycled materials and contain water-based blowing agents.
Nexseal Closed Cell
