PeterW

You’ve background checked them I take it ..?? There are a lot of MVHR providers out there who are specialists and understand the theory and technicalities of doing large scale ventilation systems - widen your search ... There is a spreadsheet on the forum somewhere that does it for you ..!

Is there a purpose to what you want to do with it ..? Internal or external AQ..? You’re not having MVHR are you ..?

What is your budget ..? For something that does that kit you’re probably £4-600 off the shelf.

Depends on perspective but NOx is probably worse in an urban environment. There is also a whole load of issues with road vehicles and PM5/2.5 coming from brake disk and tyre wear which is not being reduced by the move from IC engines. That’s not good ..!! Fixed or opening windows ..? They should still be under warranty.

Noggins won’t help. Are they proper joists or posijoists

Just get an ordinary meter and swap it for a smart meter when it’s all finished. Land at xyz etc is fine for an install

Only issue with out of date cement is the chromium and other salts that becomes more aggressive on the skin so gloves are essential.

That’s upside down unfortunately so the battens need to come off. Membrane has to go below the tile battens with a slight sag so any water will run down and not sit against the battens.

I would use grout if you have enough, if not then the step edge I would do in concrete but mix in some waterproofer or SBR too.

250ml will go a long way if you make a pad with something like an old piece of tea towel over a small sponge. Wrap over and dip it in a dish of the stuff; squeeze excess and wipe over, it won’t use that much.

Grout will do in both and the Mattstone won’t stop grout sticking to the gaps but will keep the tiles cleaner when you do grout.

That looks proper tidy ..!! Well done ..!! Clean it and seal it and then grout it.

Why do you need handles ..??

What thickness ..?? 0.9mm copper is around £140/sqm so what sort of prices are you calling unreasonable ..??

Depends which AQ measure you are using ..? PM2.5 yes, NOx no, but “pollution” has many factors.

Joists running onto it..??! For that opening with the joists onto it, you’re easily going to need 305 or larger to keep the self deflection below something that won’t cause problems for the doors below.

If you’ve not placed the SIPs order why don’t you consider a different method..? Timber frame ..? This is all well known by engineers and easy to design. SIPs have limited benefits as wall coverings and that sounds like all it is if you need a steel portal structure.

There is no DPM so basically it’s permanently “damp” I expect so PVA will just dampen off and release.

No - not essential.

How wide is the opening ..?? That steel is taking all the roof load and the parapet wall so may need to be a fair size.

So I would turn the valves off then remove the blanking plug from the far right pipe (white one) and then open the blue cap which will vent the pressure out. Then close the valve, remove the manifolds and the grey connectors and switch the manifolds and reconnect. Looks like someone has used 20 wraps of PTFE so same again to keep from leaking ..! Now open the both valves and let it pressure the manifold and the pipes. Close the bottom red valve and you may need to trigger the heating to open the actuators, but then carefully open the blue valve cap again and let it blow the air out of the pipe stub. When you get water, close the cap, put the blanking plug and reopen the red lever valve, check the system pressure and it should be good to go.

Roof is too shallow for those tiles - what is the head lap..? That is the measurement of the tile overlap - what are the brand of tiles..?? I would hazard a guess that the roof is back tracking water under the tiles as they are too flat and then the water is dripping off where it touches the fascia. Do you have any photos of it being installed...? Oh and the builder needs a new spoon to install the rendering on that left wall ... it looks like something @pocster would do...

standard downpipe is 68mm

@ashthekid superwrap is not suitable

How much space have you got ..??