Thermoblocks specified on Passivhaus development

Marmox’s Thermoblocks helped solve the cold-bridging challenge in a Passivhaus development in Wigan.

The final phase of a PassivHaus development in Wigan, has been completed with high performance Thermoblocks from Marmox being used to counter cold-bridging beneath a highly insulated timber frame construction.

The St. Mary’s project was undertaken for Wigan Metropolitan Borough Council by principal contractor Tyson Construction, with Pozzoni Architecture acting as the lead architectural consultant and BTP Architects as the specialist PassivHaus assessor.  

Matt Horrocks, Site Manager for Tyson Construction, comments: “To fit the timber frame soleplates, it was necessary to do a ‘setting out’ course across the block-and-beam, with dense concrete block serving to contain the screed. 

“The 140mm Thermoblocks were laid beneath all the external walls, followed by a 140 common brick course and then standard blocks. This was repeated for internal and party walls, but with a course of 100 mm Thermoblocks creating the fully insulated barrier.”  

Thermoblocks in 100mm and 140mm widths, along with boxes of Marmox 360 adhesive, were supplied through Travis Perkins. 

The scheme to provide affordable, easy to heat homes was part-funded by the Government’s Department for Levelling Up, Housing & Communities. The development provides eight one-bedroom apartments, nine two-bed houses and ten three-bed houses, plus four four-bedrooms and 16 one and two-bedroom bungalows.

Thermoblock

Marmox Thermoblock is a block of load-bearing insulation material designed to be placed at the base of a masonry or timber-frame wall to address the thermal bridge. Its thermal conductivity is 0.05W/mK, which will result in a significant reduction in y values when used at wall to floor junctions. 

Its mean compressive strength is 9N/mm2, allowing it to be used under most load-bearing walls and its characteristic shear strength is 0.18N/mm2. Because they are impermeable to water they can be used in damp conditions without any loss of their insulating properties. So, not only does Thermoblock thermal insulation products reduce thermal bridging, but they also create a moisture barrier.