A revolution is quietly taking place in the external joinery market. All over Europe, modified wood is increasingly being used for outdoor applications, from cladding to windows and decking. Of all the wood modification technologies, the one I am most excited about is heat-treatment. 

True, it has been around for decades but in the last few years it has taken on real commercial significance and is beginning to sell in good volumes. Although it all began in Finland with softwood years ago, many of the 90 or so heat-treatment plants in Europe are now processing temperate hardwood. And where it gets even more exciting for us is that American hardwoods are in the mix. American ash works well, but so does tulipwood, soft maple and even red oak, if its quarter sawn produces good results. 

Heat-treated U.S. hardwoods can also be sourced directly from a few specialist exporters in the USA. AHEC first drew attention to heat-treated U.S. hardwoods with the Infinity Bench designed by Martino Gamper which was displayed in the Victoria and Albert Museum’s courtyard at last year’s London Design Festival. 

If this wasn’t exciting enough a few weeks ago when we sent some heat-treated tulipwood to Carna Joinery in South Wales, who made up a trial window and were so impressed by its machining performance, stability and the fact that it meets class I durability, that they have switched their entire production over to it.

Window products were the focus of a workshop we ran two weeks ago at the British Woodworking Federation (BWF) member’s day. We had a great response and other companies are now looking to carry out their own trials using heat-treated American hardwood. 

This is a major breakthrough in our long-term goal to get U.S. hardwoods widely used for exterior joinery and we can’t wait to see where the AHEC marketing programme takes it next.