Timber Works
The Crannog Durability at the edge of the Sea
11th August 2018

Pictures: Gilmour & Aitken

The Crannog Durability at the edge of the Sea

Updating the historic Scottish crannog form of building, architects Nigel Johnston of Arisaig created a special relationship between the building and its surroundings, respecting and reflecting Scotland’s ties to the sea.

The ‘rustic’ aesthetic of timber was desired, alongside a high degree of durability to cope with the sea-edge location, and to cope with the high use expected of a community facility which also serves the increasing visitor numbers in Mallaig.

Main contractor Knoydart Construction had experience with Guyanese Greenheart, using Timber Trade Federation member Gilmour & Aitken to obtain the required sections. Steel beams and fixings were rejected in favour of traditional timber jointing. Post & beam techniques were combined with boat-building methods, including steaming Greenheart on-site into crannog curves. Steam lamination facilitated building the Greenheart ringbeam roof without centre supports. Balau was used for the trusses.

Greenheart is exceptionally strong and very durable and can be worked with the right tools. One cubic metre of Greenheart shipped from Guyana to Gilmour & Aitken in Scotland stores 1.16 tonnes of CO2 which is kept within the timber for the anticipated long life of the building.

The contractor reduced the Greenheart down to sections for laminating. No treatment was needed for the Greenheart or Balau and both timbers have settled in, with no shakes or movement. Home-grown Larch and Cedar cladding complemented the hardwoods.

Timber sourcing

Greenheart meets the requirements for Category B Evidence in line with the UK government’s timber procurement policy.

Gilmour & Aitken‘s sourcing also meets EUTR requirements. A Timber Trade Federation Responsible Purchaser, Gilmour & Aitken undertake rigorous due diligence, including their own additional, stringent checks on the all sustainable, legally-harvested hardwoods they import. They have built a long-term relationship with Guyanese Greenheart mills stretching back over 40 years.

 

Projects Info

Location: Mallaig, Scotland
Architect: Nigel Johnston
Wood Supplier: Gilmour & Aitken
Main Wood Species: Greenheart, Larch, Cedar

 

[Download this project as .pdf here]