Floors are the ‘missing link’ in domestic insulation, as retrofitting it under existing floorboards is not an easy task. A semi-autonomous robot designed by Q-Bot provides an answer, by applying SPF beneath the boards. Sarah Houlton finds out more
Widespread effective domestic insulation will play an essential part in meeting ambitious energy saving goals for residential properties. While the importance of insulating lofts and cavity walls has long been recognised, there is still a large part of the typical house that remains uninsulated – the floor, in particular suspended timber floors. Heat is lost through the floorboards, and gaps between the boards allow draughts in, bringing both moisture and cold air into the property.
However, on a purely practical level, retrofitting insulation in a floorspace is far more invasive than insulating either lofts or walls. London-based startup Q-Bot, a spin-out from Imperial College’s Dyson School of Design Engineering, has a solution: a semi-autonomous robot that fits into the floorspace and sprays polyurethane foam insulation on the underside of the floorboards.
Q-Bot’s CCO Martin Jervis estimates there are between eight and 12m suspended timber floors in UK domestic properties. ‘About 20% of overall heat is lost through uninsulated floors,’ he said. ‘Using our technique on suspended timber floors resolves the problems with heat loss and draughts.’
The disruption caused by more traditional methods of insulating floors is substantial, and the knock-on costs add up. ‘The actual cost is taking the family and the furniture out for a week, taking up the carpet, and then dealing with the floor, before having to put it all back,’ Jervis said. ‘It typically involves wedging some sort of padding between the joists. But suspended floors move over time, and even the act of putting the furniture back might introduce a 1mm gap, reducing the effectiveness of the insulation by up to 50%.’
The Q-Bot robot is far less disruptive. First, an access hatch is created in the floor, allowing the robot to be inserted into the floorspace. The robot applies a flash coat of closed-cell PU foam at an angle to the boards, which starts to fill the gaps. A second coat of foam is then added, typically to a depth of about 130mm. ‘The result is a floor that on average is 3°C warmer, with a more even distribution of warmth throughout the house, with fewer hot and cold spots,’ he said. The operators wear protective gear while the spraying is being done, but an hour after the access hatch has been sealed up again, the room is safe for people to return.
‘The robot may look like a Tonka toy, but it manoeuvres in what can be quite a complicated space,’ he added. ‘It scans the whole underfloor area, creating a 3D image, and also produces a video of where the insulation has been applied, and gives information about how deep the foam is.’ The foam is applied to British Board of Agrement (BBA) standards.
The robot can be operated completely manually using a very recognisable gaming controller. However, it is also semiautonomous, as it learns joist patterns over time, using machine learning – a technology more commonly seen in AI-driven, image recognition systems. Importantly, bearing in mind all of the services that are usually found under the floorboards, it does not spray electrical wires or gas pipes, and adds just the flash coat to hot and cold water pipes.
Q-Bot has partnered with foam supplier Econ Polyurethanes, UK and Ireland distributor for BASF’s construction PU products. Econ director Peter Woodcock explained that the robot applies closed-cell SPF. ‘It’s an HFC foam that takes 5–7 seconds to cure fully,’ he said. They are in the process of transitioning from HFC to HFO, which will be completed on a phased basis in the near future.
Closed-cell foam is preferred to open-cell by Q-Bot, partly because of its better thermal properties, but also because of the space constraints within the floorspace. ‘Closed-cell allows a lower volume of foam to be used,’ Jervis said. ‘To meet building regulations, we need the insulation to deliver the thermal properties we need in the smallest amount of space. With open-cell foam, it would be much thicker.’
The foams used with the robot have a thermal conductivity ranging from 0.025–0.027, depending on the thickness. Importantly the foam is Class 1 fire rated, meeting BS 476. But there are cultural differences – in Ireland, he said, 90% of Econ’s overall SPF sales are open-cell, whereas in the UK, 90% is closed-cell. In the US, about two-thirds of SPF is open-cell. ‘Most of our UK contractors have been using closed-cell foam for years, and they are more comfortable with its fire rating,’ he said.
The robot has made a huge difference to the ability to apply foam insulation to the underside of floorboards, Woodcock believes. ‘A lot of those underfloors are inaccessible, and while we get a huge amount of enquiries for floors, the question is whether it can be achieved,’ he said. ‘The Q-Bot robot makes it possible. Whenever we do something on social media that includes Q-Bot, it is clickbait gold – everyone wants to talk about it, and find out where they can buy one.’