Mr Punter

We had sprinklers fitted throughout on a recent development and the cost was about £2,550 per house. Average house was 4 storey 170m2.

I will speculate that it makes none whatsoever and nor will it make any difference to thermal bridging if the I joists. It will also be much easier to support plasterboard on this than it will the external tile cladding, which will be far more demanding.

The mist ones cost a fair bit more and do not typically cover the whole building. They are often specified for shared kitchens in student accommodation.

Although there is supposedly good evidence to say that timber frame is OK in a fire, there has been another today. These are far worse in multi storey blocks than detached houses. This latest one was also timber clad, which seems like madness. I assume no sprinklers either. https://www.24housing.co.uk/news/fire-rips-through-timber-framed-block-of-flats/

I have used some of the rubber stuff, but only on a garage. I did it on my own but it would have been much easier with two. There are some here who have installed fibreglass (in bone dry conditions) with great success.

Those pillars are fairly small. It won't take much material to fill them. Half a bulk bag and 5 cement would do both.

That is not the case, it was a bit of an old wives tale and never proven. Between 1:20 and 1:60 seems to work well. I assume there is a downhill slope, so I would go with this and have the drain fairly shallow all the way, providing enough cover for whatever is above. I think you can go 45m between inspection chambers and if the drain run is shallow you can use the small ones.

My guess would be this is a floating floor without a sufficient perimeter expansion gap. Ask the previous owners. You may need to remove the skirting and use a plunge circular saw to cut the boards near to the walls. I have a Makita SP6000J which gets fairly close to the edge, but there may be better. You will need to finish the ends of the cuts with a multi tool.

No, it will not be revoked if you apply for a new consent

Resilient bars seem to work fairly well and I think if you combine these with double boarding it will be better than rockwool. The British Gypsum White book has some details for floor / ceiling constructions and the sound attenuations. Even a couple of decibels makes a lot of difference.

Can't you use deck chars to straddle the bottom one and tie your bar to it? You could chop them into smaller bits if you want. https://www.buildbase.co.uk/deck-chair-reinforcement-100008639-2805084

Did you look at having the Kingspan inside the I joists? There was or is a rule of thumb that suggests that if you have more than one insulation type the less vapour permeable should go inside the more vapour permeable so that any vapour getting into the structure from the inside can easily diffuse out.

I have fitted Combimates in new builds. Quick to install and they don't take up much room. The only issue is if you leave them with the phosphate balls and don't use any water the stuff breaks down and you risk clogging the system. You can take them out if you plan to be away for over a month.

NHBC, TRADA and others recommend treated timber for external wall studs and sole plates. I guess it is extra protection against rot if they get wet. For some reason it does not apply to roof timbers. Are your timber I beam flanges treated? Again, NHBC say they should be.

I think the bearing for the soleplate must be at least as wide, so you may need blocks laid flat underneath a spanning the cavity onto eps / screed will mean the bearing would not have an even loadbearing capacity and the soleplate will not be properly supported. The soleplate should be treated timber.

Building regs are being used to improve the energy efficiency standards of new buildings. The standards for Part L, which deals with this, have become far more ambitious compared to all the other approved docs, so what worked 5 years ago will not pass now.

5 minutes is OK. Depending on temperature you could leave it mixing for an hour or two.

Do bear in mind that with trees in proximity to foundations, the actual size of tree is not taken into account, as the effect on the foundation is calculated as if the tree is fully mature. The tree size is only used if the tree is being removed, as it may lead to clay heave. Sometimes Building Control will ask for further information before they give a conditional or unconditional approval. As others have said, don't complain as you will gain nothing and may risk pissing them off.

I think it would end up a right mess.

No but it does apparently help the mortar heal small cracks over its lifetime.

Not really. Most lenders will give a mortgage on the strength of a Professional Consultant Certificate. I have used them for flat conversions, where NHBC were just wildly expensive (like £8k per flat). Everyone was able to obtain a mortgage with no issues.

We have all the stuff in a sliding door wardrobe in the back corner. We have consumer units x 2, 14 no. CAT5 terminated into patch panels flush mounted in the plasterboard, 16 port fanless switch, broadband modem, Unifi AP, phone master, TV cables, TV distribution and door entry control box and it takes up very little room. I prefer not to have a cupboard just for this. Nothing gets too hot so we have clothes etc in there too.

The water will do it no harm. Concrete cures very well under water.

Those solid barrow tyres are useless unless you are on smooth paved ground. Anything else they just bury themselves and unset the barrow if you go over uneven stuff.

I am not sure what the right angle is for. I would have 2 straight runs - 1 from utility to manhole - picking up the WC en route and 1 from kitchen to manhole. I would want access to the start of each run for rodding / jetting. This means you will not need an inspection chamber in the kitchen and the runs will be a fair bit shorter.