internal wall insulation vapour and condensation issues – use external instead

Joseph Little from Joseph Little Architects & Building Life. Consultancy Author of “Breaking the Mould” gave an interesting talk at the Server Project and Conference

Internal wall insulation is tricky and must be done properly
Strip gypsum plaster back and remove plaster, ensure there are no rising damp issue
He recommends External wall insulation as a more preferable solution and raised the point that External wall installers require training and certification while internal insulation wall installer only require a C2 tax clearance certification.
External insulation has the less vapour permeable material on the inside, the building physics reinforces and helps the installation and means that the external solution is less susceptible to problems.
He presented some interesting maps and stats as to when internal and cavity fill insulation should be used, which is dependent on driving rain conditions and location.
He maintains there is a significant lack of guidance to standards and install.
He used WUFI Pro Hygrothermal simulation. It conforms to IS EN 15026 and insulation providers need to refer to this standard and not the Glaser method.
The existing Glaser method isn’t suitable for internal insulation under IS EN 13788. We need a move towards WUFI.

One comment

  1. John Cloonan says:

    From experience there is a lot of truth in what Joseph Little says with regard to external and internal insulation.

Leave a Reply

Your email address will not be published. Required fields are marked *