A trio of highly experienced and multi-skilled tradesmen who specialise in the renovation and restoration of traditional properties working across the Cornwall peninsula, are currently employing three different thicknesses of Marmox Multiboard as they seek to tackle not just damp issues, but also generally poor energy performance within a stone-built cottage located in the town of Hayle.
Andrew Bourne of ‘Bourne to Build’ and Mike Chellew, who trades under the name of Southwest Renovations, had worked together since the early 2000s before Peter Adams joined them five years ago, adding his talent for bespoke carpentry to his partners’ prowess at stonework, roofing, building services and other trades. Together they have undertaken a variety of domestic challenges including the ‘ground-up’ rebuild of a large property in the iconic coastal resort of St Ives, where there had been little other than the outside walls still standing before they stared on site.
In the case of the Hayle project, they are renovating a 150 year old home built from the local shale type rock which, along with some later blockwork walls, are being lined with 40mm thick Marmox Multiboard, while the 10mm version of the product is being used to upgrade the window reveals without encroaching on the actual frames. In addition, 60mm thick Multiboards have been used to cover a concrete floor: radically improving the insulation performance and providing an ideal substrate for the installation of a hydronic underfloor heating system. All of the Marmox Multiboards have been supplied through the Penzance branch of Bradfords Builders Merchants.
In the past we have typically used Multiboard for renovating bathrooms, here we are installing it across the inner face of all the external walls.
Peter Adams comments: “Generally we go in for quite modern upgrades of period properties to improve the amenity and greatly extend the life of the buildings for our clients. In the case of this three-bedroom house in Hayle, the owner was seeking to significantly improve the thermal performance of what had been quite a cold house which had also suffered from damp problems in areas. So, where in the past we have typically used Multiboard for renovating bathrooms, here we are installing it across the inner face of all the external walls.”
“Then as well as installing a new damp proof course we have laid new joisted timber floors across much of the ground floor, but were confronted with a 60mm drop in level in one place. Therefore, to build up the existing slab we bedded the 60mm Multiboard into the adhesive.”
“For the wall areas, in addition to the dot-and-dab plasterboard adhesive, we are using the Marmox washers fixed in place with drywall screws or standard screws where there are any timber studs. Then the walls are all being plastered with a coat of multi-finish. A massive bonus to using Multiboard instead of standard plasterboard is the difference in the sound quality – you don’t get that hollow sound when you tap it: the walls just feel more substantial and it really adds to the overall quality of the build.”
Marmox Multiboards are manufactured from extruded polystyrene or XPS encapsulated in reinforced polymer concrete, produced in a range of thicknesses up to 60mm and offer a variety of positive physical characteristics in addition to being fully waterproof. They are both light to handle and easy to cut, while still being able to sustain substantial loadings if required, such as for flooring applications. They further offer good thermal insulation performance, helping to cut condensation risk and reduce fuel bills. The surface coating presents an ideal substrate for direct tiling as well as to receive render or plaster finishes.