Marmox Thermoblocks Insulate Tudor Reconstruction

The reconstruction of a rambling old farmyard close to Ely in East Cambridgeshire is making use of well proven Marmox Thermoblocks, specified in three widths as the ideal solution for tackling thermal-bridging around the building perimeter as part of a well-insulated design. Mitchell’s Barn is replacing a sprawling complex of dilapidated tin cowsheds and a rather more attractive oak barn which was founded on a plinth of Tudor era bricks.

The original planning permission allowed for the reconstruction of the latter structure, but when the owner, Ben Hughes came to dismantle the outer envelope, much of the timber was found to be rotten while the bricks showed significant frost-damage. The work which got under way earlier in the autumn, is therefore seeing both 215mm and 140mm wide Thermoblocks being used to support a 800mm high brick base which will then carry the conserved oak beams, creating a traditional looking inner ambience.

Ben Hughes commented: “I have taken responsibility for the design as well as the construction of what will be a four-bedroom, three-bathroom property, as a self-build project with the help of a builder, Peter Axton who I have worked with on previous projects. As it is such an exposed site, the house takes the form of a three-sided courtyard which will shelter the south facing terrace. Primarily a Class Q conversion of an agricultural building into a residential building, the new structure is all single storey, but with a mezzanine to accommodate the plant and services that will include an air source heat pump and MVHR system."

"Essentially, we are rebuilding it at the same scale using the same traditional techniques as the original, with additional oak for the frame coming from a tree felled on the site. In order to meet Building Regulations, we have gone for an insulated cavity wall with 150m of PIR insulation for the floor and roof, but when I was researching how to address the issue of thermal bridging at the floor wall junction, Marmox Thermoblock seemed to be the only targeted product solution. In terms of the loadings and the insulation values I am certain it will work well. It’s a good mix of old and new technologies and I’m very happy with the design overall.”

In total Ben and his bricklayer have used 144 x 140x65mm blocks plus 18 x 100x65mm blocks and 50 x 215x65mm blocks, purchased from Insulation Shop on-line. Bedded in conventional mortar, the stepped overlaps between adjacent Thermoblocks have been secured using a high performance (Sika) adhesive.

Ben concluded saying: “The work is progressing well and my bricklayer, Danny, has had no issues with laying the Thermoblocks or cutting them where it has been necessary. Some of the packages, such as for the windows, are still to be placed, but I am confident of the finished property exceeding the current Building Regulation requirements and making a very comfortable home.” 

He is also consulting with Marmox’s technical department over the use of the company’s even longer established Multiboard thermal tilebacker board and other products for fitting out the bathrooms, including at least one wetroom. With a proven track record going back more than a decade, Thermoblocks are available in widths of 100, 140 and 215mm and feature a unique design where two rows of high strength epoxy concrete mini-columns are encapsulated in sections of XPS (Extruded polystyrene).

They are attached at either end to the top and bottom layers of glass-fibre reinforced polymer concrete to achieve a strong bond with the rest of the structure. As well as being used in basement construction and around the floor-wall junction – supporting timber frame as well as masonry walls – Thermoblocks regularly feature at first floor level and beneath parapet walls. They are further employed for swimming pool construction. www.marmox.co.uk