Grimaldi

Helpful to know - I've received a quote from a local timber yard for custom made untreated and it was more than double the cost of the timber merchant's treated stuff. Mainly worried obout some sort of toxins being emitted - the MVHR system maybe a mitigant keeping concentrations to a minimum.

Both of the above sizes would work for me.

Just wondering what people are using for internal service battens? All that my timber mercharnts stock are either 25mm x 50mm treated roof battens or 38mm x 50mm green treated unregularised carcassing for outdoor use. Are there risks to using these treated timbers indoors - thinking about checmicals? Any suggestions for alternatives - ideally this would be my preference to avoid any risk of checmical leaching into the living space through the plasterboard. Thanks Grim

I am considering a Zehnder Q450 and was wondering whether to go for normal vs enthalpy exchanger. I am located in the Highlands of Scotland. My limited research shows that the decision is a trade-off between efficiency vs maintaining more optimal humidity in colder / dryer climates. Ideally I would go down the normal route given higher efficiency but wondering if anyone has issues with too low a level of interior humidity in colder parts of the UK. I can imagine real issues in places like Scandinavia where absolute humidity at temps of -20 may be super low, but wondering if a more typical Scottish winter temp of 0-5 degrees merits an enthalpy exchanger? Thanks