PeterW

In that case just dish the metal a bit around the washers ..?? Should recess them enough.

Isn’t that where the bolts for the frame go, so a couple of penny washers and a coach bolt through the frame on each one .??

Ah ok. Don’t forget to prime the back of it before you use it to make it last longer.

80-90% has to be the minimum and I can’t see how one below that is on the passiv database, don’t think it’s on the SAP one which means it’s not recognised for SAP scoring if I understand correctly.

1m vertical would work - I’m assuming it’s exhaust at the top and intake bottom...??

Why are you replacing the beading ..?? Repair may be quicker and easier - is there anything actually wrong with it ..?

@JSHarris What’s the optimum spacing (vertical and / or horizontal) for MVHR..? I’ve got an option as to how to split some vents and can’t decide on the best split

You need to pull it out, fit a spring loaded backdraft flap at the fan end and then refit the tube and a new cowl or cover.

Use FrameTherm32 for the rafter fill, gives 0.14 when you take into consideration the 25mm PIR stopping the bridging of the rafters. This was on a 600mm rafter spacing.

190mm of Earthwool between the rafters, 25mm PIR over secured with 25mm battens at the joists and then 25mm infill, taped at all joints will work for you from both uValue and airtightness perspective and is also good for decrement delay.

AlOx paint isn’t really needed in this situation - just a good primer and then a couple of coats of undercoat. Buy a “system” and it should all be fine - your local Johnstone’s Paints will make up any top coat colour for you from a sample or a code.

Check one isn’t a CO sensor and that has set them off. Not a lot you can really check on an ionization smoke alarm.

How does that meet regs ..?? At that you’d be cheaper just using full fill batts

You could test it by parking one of the Capri’s in it...

Standard 7N medium weight is fine for that. What’s the insulation spec..?