How do I go about drilling holes in my exterior walls for MVHR ducts (2x) to atmosphere?
What tools should I use? How should I do it? Guidance, suggestions & tips most welcome!
External walls (closed cassettes)
OSB, 12.5mm, Smartply Propassiv – inside
Empty cavity 240mm, to be later filled with blown-cellulose insulation. Studs every 600mm.
Magply, 9mm – outside
House warp: Tyvek Firecurb
Ducts (2x)
Ubbink 160mm (internal diameter) insulated ductwork
External diameter: 192mm
External cladding (not yet installed): Cedral lap planks (190mm, 30mm overlap), over treated battens.
External wall terminals (x2):