News Ticker

Lower air leakage performance sees “Natural-SIP” specialist warm to SterlingOSB Zero

An custom housebuilder, whose focus is on achieving excellent energy performance coupled with high environmental standards, has adopted the use of  SterlingOSB Zero from the range of  West Fraser, in particular favouring the well proven panel product’s superior standards of airtightness. Makar Ltd designs and manufactures a range of affordable homes, one off exemplar homes and commercial properties.

Established at Clachandreggy near Inverness in 2002, Makar Ltd has delivered an average of one property a month over the past two decades, concentrating on exceeding the requirements of the Building Standards (Scotland) as well as meeting all clients’ aspirations for style and comfort, achieving this through the use of innovative off-site construction methods.  Creating homes that are healthy to live in and good for the environment is an ethos for which SterlingOSB Zero is ideally suited, given its use of responsibly sourced timber and featuring zero added formaldehyde.

As Makar’s Scott Reid commented: “Instead of a standard SIP panel which is filled with polyurethane foam insulation, we employ the 11mm  SterlingOSB Zero as a lining to the inside face of the 220mm wall structure to provide racking, retain the Warmcel insulation and provide airtightness.  Significantly, we ran independent ‘blind’ testing comparing the SterlingOSB Zero to one of its European made competitors and it came out as showing a variance of 20%.  Both the dimensional accuracy of the boards and their actual structure contribute to our achieving a figure of 0.6 (M3/m2/hr) which is in line with PassivHaus standards.  Then we add a 40mm wood fibreboard externally, plus on the roof there is a 245mm rafter depth with two layers of the wood fibre with multiple covering solutions available.”

West Fraser‘s renowned SterlingOSB Zero boards appear again as part of the build-up for the intermediate floors, where the 18mm thick version is installed to offer a working platform for the duration of the build phase, as well as providing racking strength to the structure overall.  This deck is then normally covered by a hardwood flooring overlay.

Scott continued: “It is one of the key selling points to our system that the selection of materials serves to control moisture movement across the fabric of the building.  We don’t  use any plastics in our buildings and the SterlingOSB Zero is therefore acting as a partial vapour barrier – and we use a condensation risk analysis. This demonstrates how the moisture can move through the fabric and be expelled. Then for the past ten years, there has been MVHR* in place to provide tempered fresh air to the occupants.” ( * MVHR Mechanical Ventilation & Heat Recovery).

Makar has found a formula which is resonating with a widening customer base, as Scott concluded: “We are set up to deliver 12 custom designed homes or commercial properties a year – though that capacity is steadily increasing, and we have recently made changes to the set-up, where our system will also be used for affordable housing.  We have also done some work with Logie Estate.”

All West Fraser panel products produced in the UK are net carbon negative and manufactured in mills that have obtained the coveted environmental ISO 14001 accreditation.  Responsibly sourced, the panels are FSC® certified (C012533) and created from locally grown timber, cutting embodied carbon from transportation.

For further information, call 01786 812 921 or visit Uk.westfraser.com