Oz07

Without looking into i'd imagine herringbone is more forgiving on the flatness of subfloor as its smaller units. I could be wrong though. I imagine most flooring pros nowadays always want to latex. They know what they're going onto then.

Why don't you rip the existing ic out, put a 5 inlet ic inline with your run and extaend the existing pipes to meet to new ic.

I've done a good workaround for that osma 90 base above. I have a load of long rest bends and if you look at these its marked where to cut out to use on flat. Then I set on lean mix and benched around the opening with compo and just used standard risers around it. Worked a treat. Not sure how much cheaper it is if you have to buy the bends I already had them.

Do you guys cover the outside of insulation with anything to stop rodents getting in below door thresholds?

Surely you want them perpendicular?

I'd put the dormers in if it were me then apply for NMA if the council spot it. Surely they've been put back in their box by the inspector now anyway so they'd be reluctant to throw their weight around. What's relationship like with neighbours

Wait till you see the price of materesses

@JohnMoare you including land costs in the 1800 or is that on top? I was just making the point that here you can buy all signing dancing properties on good plots for 4k m2 all done and dusted. Annoyingly I'm interested in a plot which is currently available at auction, and it just seems a terrible time to buy all things considered. They are rare round where we live at the minute in a good school catchment so might have to hold my nose and buy it.

Yes

Even the nice houses round here aren't going for much more than £4000m2. I'm talking great spec, great location. Seems its not worth building atm if prices to build are as high as they say. Just about to offer on a plot next week too...

min 1 in 80 with 4" pipe and at least a loo plumbed into it i think. I'd be wary of going any less on 4" pipe. Has to be steeper if it's not getting as much flow down.

There aren't maximum falls anymore as I understand it. PVC pipe did away with that

Just do plan A I bet the BCO approves. Plan B looks messy to me

Ive encased in concrete before but not sure its nessecary. See so many sites without any protection and nothing ever happens. I knew lorries would be going over so played it safe. See how many reduce dig for new driveways exposes drains that work just fine without protection. I think its probably more important to have a tight trench with minimum pea gravel needed to comply if under a driveway.

Eliminate the 45 bend after the y branch just position the y so you are coming straight up with a 90 possibly with a short straight stub of pipe between them