PeterW

700 cubic metres / hour is 195 litres per second - are you sure that number is correct ..?? The minimum under building regs over a hob is 30 litres / second or 108 cubic metres / hour so I would check the spec.

Remove and replace with Heras fencing tomorrow. Job done if it’s more than 1m from the highway as from memory that’s the legal distance.

Arbo is just a brand - they do low and high modulus silicone. What deflection has the SE specced on the steel and what have they allowed for on the window design

Why are you calculating extract rate ..?? Kitchen extraction is a standard value depending on whether it is above a hob or not and set in Part F. It’s 60l/s if not above the hob, or 30l/s if above/adjacent

Also look at this place as it’s decent quality and 75mm guttering https://www.plasticdrainage.co.uk/2m-half-round-gutter-10802.html

Pyramid maths is easy .... how high do you want the peak in the centre ..??

Yep usually under a rafter block or rafter tail.

Easy Pads aren’t suitable for an extension, you need to put in foundations that match the house construction, or use one of the ground pile systems with a concrete ring beam.

You can also get GSM power failure alarms that are about £150 and they have battery backup. It can be useful to have some of these sorts of alarms when you’re very dependent on the systems working !!!

Yeh it should - most of the pump station controllers have pump failure alarm along with a liquid level alarm, but some come fitted with a power failure alarm. This sort of thing should be used with a battery backup. https://www.tanks-direct.co.uk/high-level-alarm-battery-backup-for-sewage-pumping-station-cw-float/p3139 They can also be retrofitted with a power failure alarm.

Does the pump / tank not have an alarm fitted for the high level alerts ..?? Most pumping station should have them.

You need these to support it https://www.plasticdrainage.co.uk/rafter-top-gutter-bracket-2-9365.html

Vermiculite concrete will compress

Ok so this is all additional cost ..? And wastage ..? If I have a run of joists at 600 centres with the final one at 275, and a total span of say 3875mm, then a board won’t work. With 22mm Egger, you can land the offcuts (so the ~1m length) onto the next run as it’s over 2 joists and then carry on as normal. No noggins or intermediates required and glued up it meets all the MIs. 18mm OSB doesn’t allow that, so you now need to slow the process down and nog where the boards fall or bin anything that’s not a multiple of 1200. Doesn’t make sense and is more costly, increased labour and also needs additional components. Add in the 42 day weather guarantee with Egger protect (which you don’t get unless you go OSB4) then why would you do it ..?? It’s not even a cost saving these days with board pricing.

About £15k more than I would be paying ..!!

Whats wrong with 22mm P5..???

No - 22mm Egger can land anywhere and is self supporting. And you can’t frame posi or JJI joists easily with noggins so it’s more of an issue with modern floor systems.

But if the short edges are not supported or land between then you need to nog it out.

Not sure where you are getting your numbers from on this ..?? Good acoustic UPVC should be around the £250 mark.

Ok so no real issue with the height as no-one will really check. There is a good guide here on what is allowable but that roof light will cause problems if it’s much more than 60-70mm https://planningjungle.com/wp-content/uploads/Part-1-of-the-GPDO-Visual-Guide-FREE-VERSION.pdf

18mm OSB is support all 4 sides even with T&G so can’t see the benefit tbh as any cost reduction will be lost on labour and frame out etc.

You can’t start inside without a decent roof covering - are you doing it yourself ..?? You could notionally build block sleeper walls for the stud work to work off and then install stud work and the other trades can start but you need that roof on ASAP.

TF (with windows / doors..?) Roof Insulation UFH Screed Studwork MVHR Sparks/Plumber

Mapei

Yes laminate is smooth and it releases with ordinary veg oil. Mesh is midway through just for strength And I recon they are £3 each or so - Yorkstone would be £35-40 for small bits 65mm thick.