Healthy homes call for healthy building materials and their appropriate use. Ben Humphires, director at Architype, is an expert in design and construction of healthy buildings. We've asked him about his experience with wood fibre insulation.
Key benefits for us are that it is made from renewable material, and it is good from an embodied carbon perspective, especially if you include carbon sequestration. The manufacture of the product is certainly lower in terms of pollution and environmental impact than petrochemical alternatives and the resulting product is certainly more healthy to install and for occupants. It is a good regulator of moisture and the density of the products usually ensure better decrement delay than their synthetic counterparts. It’s also recyclable and reusable.
Many years ago - I think we were introduced to it by Natural Building Technologies or Construction Resources.
We have used the product in new builds and in refurbishments, and in various forms, i.e. as flexible insulation between studs and on the outside of walls, either with a rain screen or in combination with a render system. I would say it is particularly beneficial when you want to ensure a good level of breathability and where the environment is relatively humid and need good hygroscopic properties from your wall and roof build ups.
While we have used externally in combination with a render coating, clearly if water gets into this system, then it can be problematic and reduce the effectiveness of the insulation. Detailed properly, and with appropriate protection during construction, then problems shouldn’t occur, however, some clients are still nervous of using this approach. Cost is sometimes a barrier when budgets are tight, however, when this has to be reviewed against the considerable environmental benefits, then usually a strong case can be made.
I wouldn’t use wood fibre insulation in a warm roof construction. One manufacturer once told us that it was appropriate, but the build up is very unlikely to be breathable enough to allow moisture to escape, thus presenting a potential ‘rot’ problem further down the line!
If you want to learn more about Ben's experience in healthy buildings design and construction, sign up for the ASBP Healthy Buildings Conference on 14 February 2018 at UCL, London.
Find more information on healthy buildings here.
Learn more about wood fibre insulation here.