George

Could do but that'd be 25% more steel weight.

Yeah it'd need the 10mm bars as well, not just a swap to A393.

Did you ask them if the A393 mesh + 10mm loose bars @200mm centres is an acceptable alternative to the B785 mesh? Difference in cost may not be massive but lead times could be better.

Don't see B-meshes out in the wild very often. # As it's a suspended slab it probably does need fairly heavy-ish reinforcement. You could replicate the B785 spec with A393 with additional loose 10mm bars every 200mm (so slot between the A393 squares). This would be easier to get hold of. However do make them check because a 200mm thick slab with 10mm main reinforcement is pretty hefty for domestic purposes. Not mad or necessarily over the top... but... hefty. Engineers are human and usually working to tight deadlines and low fees. Pity them and never trust them/us blindly.

Bigger washer = lower pressure

The timber ledger acts as a very large washer so the force is fully distributed rather than being a point load. Using resin anchors would mean there's only a nominal tension in the anchor (and resulting compression in the supporting material).

I've always understood a drain to be a pipe serving an individual household and a sewer is a pipe serving more than one household.

I looked at trying to undertake training for both ICF and insulated slabs. The slabs were easy enough - the insulation just acts as a slightly springy subbase. But I could not get any good information from the ICF industry group. As I understand it, it's just a reinforced concrete design so there are only a handful of design checks unless it's a very large building.

The king post is actually in tension. This is why you will see iron bolts or straps, to account for the poor performance of timber connections in tension.

Yeah of course. Sorry I didn't mean to come across as too negative but without more information it's not appropriate for forum advice. If just boarding out for light storage I wouldn't be particularly concerned. But a high point load could cause deflection, cracking and slipping tiles.

The ties work in tension as part of the truss but it is the truss that needs to be checked. The compression in the principal rafters and struts, as well as the tension in the king post, would be considered as a whole. It's up to you but you seem decided not to seek professional advice. I don't think anyone else on this forum could or would be able to provide any additional reassurance on your plan.

That's fine but the trusses still need to be strong enough.

Due to the point load of the UVC it'd be sensible to get an engineer to come and assess the trusses.

With the old multi-fuel stove I never found it difficult to maintain a thick layer of ash. I've gone for a (ecodesign) multi-fuel to replace it but never intend to use it for coal.

Yeah either will work OK.

You may need a waste exemption licence if it's agricultural land.

You need to get this checked by an engineer. Ceiling joists tie the rafters together and prevent roof spread. There are ways round this (the purlins may be sufficient) but potentially as sketched this is not a suitable arrangement. .... ruddy architects.

That formula is for non-cohesive soils so isn't applicable here anyway. A formation level a minimum of 450mm below finished ground level is good for most of the UK. For capacity, in the absence of ground information, go 150mm into good virgin ground. For mass concrete, foundation thickness a minimum of half the width (although depends a bit on the wall - part A rules should be ok for a small retaining wall). For retaining wall, top of concrete ideally 200mm below low side ground level.

CO2 per kWh delivered is already a lot lower for ASHP, thanks to the '200%' of energy coming from the ambient air. Mains gas is probably cheaper for the next few years but that could change. In my calculations oil and LPG were more expensive, especially if you have solar panels/battery/smart tariffs.

Thanks - yeah I knew about generating QR codes, but wasn't sure how tot get the automatic email a picture function. Although maybe that's not possible for security reasons.

You know what would be good - a QR code next to the tell tale which would automatically email the picture to the engineer. Remote on site monitoring. I have no idea how to technically achieve this.

I would have thought that the door / fire system was always something you needed to pay for, you just didn't know it. In which case I'm not sure you could claim the full cost, just an extra over which might not be very much. But even then the standard they need to meet is reasonable skill and care and not perfection. If they had flawed information and if they can point to a BC sign off they/a court could reasonably have thought they met that standard.

- Prevents freezing - Looks better - Fewer wall penetrations (best will in the world bricks don't seal perfectly to a circle) - Less susceptible to damage and corrosion - Allows for toilets to be placed anywhere in the building / avoids long horizontal runs internally No reason not to

You should certainly have an insect screen on the external air intake. I like insects, but not in the house. Spiders I live with, but flies get swatted, trapped or fried, I'm afraid.

What did you charge for the day?