PeterW

RAK do a decent range. And hard water isn’t an issue - V&B and others also do some very good coatings that make cleaning much easier and hard water less problematic.

The polythene foam is an expansion joint and should be hidden behind a layer of a decent structural mastic. The hole at the top is crap - that’s one of those where the brickie says it’s the roofers job, and the roofer says it is the brickies job.... The potential upside is if you get an endoscopic to camera you have an access point !!!

Welcome ..! Let’s have some more details then - a photo of a nice muddy patch is always a good opening shot..!

Flush strength is down to the cistern rather than the bowl. Not a big fan of rimless but the V&B Architectura range are really nice. Downside is they need a V&B seat, and these can be upward of £120 for the soft close quick release ones.

Is this for soundproofing ..? If so you need to use acoustic fibre insulation and an air gap. It’s a standard detail for sound control.

Standard running P-Trap with an appliance connector on the end and straight into the stack. Use a strap boss on the stack and one of these on the trap.

Yep nothing wrong with that. May want to try and get a few screws into timbers shaped to sit on the flanges of the RSJ.

Sand cement slurry is the wrong side - it goes on the inside of the inner blockwork under the plasterboard.

Seriously.. they were designed for a purpose so that cavities didn’t need to get bigger .. and they are horrid things ..!! You can’t fix anything into them, and they crack if you stress them. Just use mediums, use a decent cavity and crack on. 170mm is over the maximum on a standard lintel so you’re on splits anyway so go to 200mm and get the benefit. It is because they aren’t set up to deal with that increase. Look at some of the MBC builds on here and they are 0.12 with pretty much zero heating bills - and soundproofing that is the biggest benefit above heat insulation.

You’ve used aerated blocks, I’ve used standard mediums as I wouldn’t use aerated blocks if you gave them to me with a £10 note taped to each one ...

Medium block both sides and a 200mm cavity will do that with either Rockwool or EPS bead at 0.032

What’s your target uValue for the walls ..?

you cannot fill the cavity when using PIR. Either use 120mm PIR with a cavity OR Use 150mm blown bead or rockwool.

From memory the EPS graphite beads were £12/m at 150mm cavity.

Quicker and easier as the brickies don’t need to install insulation. But you need to keep the cavities clean so may need to use snot boards. Beads get everywhere - that is a good and a bad thing ..!

As others have said, when you tape stuff it’s belt and braces but you also spot the detail - @Cpd is spot on that you find the gap and shove the foam gun in it. You will get to know your house much better, and you’ll slowly remove all the potential issues. Foil tape isn’t expensive - get some 100mm rolls and you’ll be soon ensuring the whole place is airtight and you’ll benefit for years to come.

You can’t full fill with rigid insulation. It has to have a cavity on the external side. Some of the “full fill” rigid boards have a 10mm spacer system built into the front to keep a cavity. I would always go beads these days and where possible up the cavity to 200mm. 300mm wall ties aren’t much more expensive and as you’re using block and render then split lintels are easy.

Wickes Tough and Washable

Sand cement slurry on the inner blockwork.

Because it’s not a structural product. They are different to liquid screeds and have very different properties.

You don’t have a partial fill - you can’t partial fill with rockwool, it has to be retained both sides with masonry. 400mm build up seems to be 15mm plasterboard and skim, 100mm block, 170mm cavity, 100mm block and 15mm render ..? If so, 170mm rockwool and 170mm EPS are pretty much equal, 120mm PIR with 50mm cavity is probably 25% better but more difficult to detail and will cost more.

You can’t use that design for UFH - there is no insulation under the slab and it also seems to show an additional layer on top. How low has the SEng drawn the top of the concrete in relation to the finished floor of the existing house ..? And why a raft for such a small extension ..? What are the ground conditions ..??

You’re not managing subs though so these become reasonably irrelevant. Is a £200 sparky available tomorrow better than a £190 Sparky available in a month ..?? Get 3 prices, get the average and take the one nearest the average. And don’t be afraid to ask for their day rates ..!

Min 140mm PIR in the rafters or 350mm IIRC if it’s flat laid rockwool.

Yep - 300 from an internal corner and 150 from a downpipe or soil pipe.... that should have a plume management kit on it to take it upward and turn at 90 degrees to the wall. https://nhbc-standards.co.uk/6-superstructure-excluding-roofs/6-8-fireplaces-chimneys-and-flues/6-8-12-gas-outlets-and-terminals/ See above - can you take a photo straight on to this..?? And is this a major developer build with an NHBC warranty ..?? Fire barrier ..?? Will look like either a blockwork wall or a lot of chicken wire stuffed with insulation inside that roofspace on the boundary.