MAKING PROGRESS IN THE BASEMENT
One job we’ve been able to get on with alongside building the main superstructure is the basement floor. First up was laying the rigid, high-density insulation and protecting it with a membrane, which ICF Contractors did for us. This isn’t the exact product the architects originally specified: we’ve found an alternative in the form of Cellecta’s Hexatherm Xfloor 300. The 160mm-deep version delivers the compressive strength and U-values we need, and has come in at about half the price for materials and labour as our original quote (saving us nearly £3,000), partly because we only need a single layer. Handily, the total depth of insulation is also slimmer – so we’re gaining 40mm of headroom.
Soon after, Screedflo came on site to pour our basement floor screed. We’re using a liquid anhydrite product on this storey, which is quick to install and dry, self-levelling and mixed on site so that you know you’re ordering the exact quantity you need. We’re not installing underfloor heating down here, so we only need a 40mm screed depth. To achieve this, the guys set up a laser level and deployed special tripods (which look like mini versions of something out of War of the Worlds). Once they’re set to the right depth, the liquid is pumped in. The job was finished in less than two hours, and it takes just 48 hours to dry enough to walk on (with a little aftercare and ventilation to ensure it dries out fully over seven days – saving a couple of weeks compared to normal screed).