Oz07

I understand its pretty good to use aircrete as the thermal break and keep them dry with a dpc. Perform pretty well for lot less £

I got 1.2 m3 hr whatever that is in ach. Masonry cavity build with dot and dab. Large coated blockwork internally

Try and get away from aircrete. I think you can get .18 with medium dense and 150mm cavity from memory. Maybe dot and dab improves the score slightly

Are the regs super strict now with walls having to hit .18? I seem to remember this being the case and swapping some cavities from 100 to 150 in 2015. Saying that new build sites round here still plugging away with 100mm cavity albeit with thermalite blocks. Now I'm thinking maybe you can exceed .18 if you offset elsewhere.

4m max potentially get it down to 2m with different svp position. Nothing set in stone yet. When i read the regs its asking for 18mm in 1m for fall

Interesting. Just at very early planning stage so nothing concrete yet. I think the wall hung wcs have that 82mm soil pipe from memory? Can you come out of a normal wc pan into 82mm without problems? So my option is smaller waste or less fall. Max run would be 4m, prob a bit less. I'll have to remember to feed waste pipe in when putting joists on. I did it last time with a 2" pipe and small joists centres saved having to try thread it in after.

Has anyone successfully ran any length of soil pipe perpendicular in pozi joists? Im thinking each cord being around 45mm gives you 135mm between so 25mm. Maybe gives you room for a couple of metres of fall at 1:80 if you can specify the metal webs to give you room. Just considering the design of something and which way to run joists. I've also seen jobs where the joists stop short of the wall by a couple of hundred mm and sit on a trimmer like a staircase. Maybe there's even some obscure pipe size you can use for waste like 90mm od?

Just if they're on show I think. How much is a class b red engineering brick nowadays? Used to be about 20 pence.

Ive Just been assuming this ceiling is boarded. What an idiot. You might get away with poking them thru the inside.

Well I don't think you will ever be able to get a full length into the space with enough bearing on both plates. So looks to be leaving you with option 2. I'd be looking to strip the bottom row of felt and replace.

Can you lift the bottom row of tiles and felt and slide the new joists in from outside

Picture would be helpful of the existing situation. Can you put a plate ontop of existing ties or would it not be above existing due to rafters

Probably more likely to find a firm with a rep who does site visits than a fixed showroom

What if you go the route with the neighbours drain or culvert but fit non return valves to their pipes?

Has anyone ever bedded one in on foam?