Sustainable Building Forum
The place to share best practice advice about all things sustainable building. Use the search icon to find the topic you’re interested in or register as a member to comment on topics and ask your own questions.
What insulation should you use to insulate your existing roof?
There are many types of insulation you can use and there are some that we’d suggest you really shouldn’t. At Back to Earth we encourage people to move away from the seemingly high performance PIR foil faced foam insulations partly to reduce the use of plastics and also because they rarely perform as they should or create spaces that are particularly comfortable. Their imperviousness to moisture can be an issue in older buildings and when they shrink the performance of the roof decreases.
We would strongly recommend that you use only vapour permeable insulations within your roof which typically means some form of wool/fibre type product between the rafters with more above or below. Compressible and flexible products work best between timbers as they can be squashed slightly as they are installed to ensure there are no gaps and you have a tight fit.
Other insulation properties to consider are acoustic insulation and thermal mass. Higher density insulations, such as wood fibre insulation, absorb sound very effectively, ensuring the space within the roof is quiet. They also store large amounts of heat and can be used to shield spaces from hot summer sun as well as retain heat during the cooler months.
We offer dynamic heat and moisture modelling as well as condensation risk analyses.
Back to Earth is a natural building material supplier. We're not your typical builders' merchant though and instead work closely with our clients during the planning, designing and building phases of projects.