Selby Affordable Homes

Modular housing installed over Mrmox Thermoblock breaks at Selby

A Yorkshire based groundworks and civil engineering specialist is making innovative use of Marmox Thermoblocks in constructing the oversites across a development of over 100 affordable homes which are being craned into position as factory fabricated modules.

Alfa Site Services is experienced in working with all of the UK’s major housebuilders, as well as infrastructure specialists like Kier and has purchased 720 of the 600 x 100 x 65mm Thermoblocks from Encon Insulation of Leeds, with the merchant also supplying some 50 cartons of Marmox’s versatile high-performance 360 adhesive, used to bed the blocks and bond their overlapping joints. This well proven installation method helps achieve the accurate alignment and stability necessary for the modules to be craned into position.

Alfa’s Senior Manager Site Services, Rick Harrison, commented: “The site was originally a railway siding, with the made-up ground requiring 2.5 metres deep foundations and then levels are being built up by a metre to deal with flood risk: leading us to lay three courses of blocks.

Installing the Thermoblocks using the 360 adhesive is quite time consuming, but it is basically a very good product and there have been no actual issues. Once the course of Thermoblocks is complete we hand over to the developer’s site management team to actually install the modules. This is a significant project involving a number of technical aspects which were new to us, but I think this could represent the way ahead for construction and we have been proud to be involved as the principal contractor.”

Marmox Thermoblocks are available in widths of 100, 140 or 215mm and are formed from sections of XPS (extruded polystyrene) encapsulating two rows of high strength, epoxy concrete mini-columns.

These are attached at either end to the top and bottom layers of glass-fibre reinforced polymer concrete, to ensure a good bond with the rest of the structure.

As well as combatting cold bridging where the inner leaf of masonry walls abuts the floor zone, Thermoblocks are also often utilised to support timber frame construction or at vulnerable upper floor junctions, including beneath parapet walls.