peteypops

Thanks all. So I guess a vital piece of context is that this is hooking up to a water treatment plant, just out of frame from the picture I posted. So no sewer issues as such, but, back pressure is still possible I guess. I had similar misgivings about venting into the loft space, (outside the thermal envelope) and I like the the idea of a separate external vent pipe so as not to have to penetrate the roof, but getting one up to the ridge line is tricky

I've requested from our architect to have our drainage arranged with an AAV for each toilet. These will be contained in walls or boxing. This would look like this - My architect insists that the long run needs an open SVP running into the roof space as follows - Can anyone offer any insight on this as I'm pretty sure the AAV's are adequate. Cheers Pete

Nice! I'm still formulating a plan to lower the bath down from where it is in the picture, but the angled side panels is an intriguing idea. I'm gonna have to pay particular attention to the sealant around the bath but I'm kind of a bit OCD about that anyway.

Yeah, that's how it's normally done, so same thing but with the tiles raised around the bath to make a flat surround. My wife has hip mobility issues so this would allow her to sit and swing her legs in to the tub without having to support her weight on the edge of the bath itself, which hurts. So it would look like this - Sounds like what your saying is that back board is strong enough if it has a bit more support than ply.

I'm planning to build a level "deck" around my bath tub, so the tiles are at the same height as the edge of the bath or near as dammit. I'm not sure about using the foam expanded tile backer board horizontally, how strong is it? When I've done this sort of thing with ply I've been able to stand on it with no concerns at all.

Ta.

Cheers. Out of interest, do you have a preference for sound insulation?

This is probably a stupid question, but, if I buy a 110mm pipe clip, what distance from the wall does this offset the pipe? I singularly failed to finds a manufacturer that specifies this so I assumed it must be a standard. However looking at product photo's they are apparently quite different. When I've done soil pipe in the past this has not been important but this is going into boxing. Is there a standard or is it random?

Correction, it's a stone resin shower tray with an acrylic surface, so they call it acrylic.

I've used tile adhesive before to good effect, but as you say, that will depend on the tray itself.

Fair comment, thanks.

UK regs say - 3.68 The length of supply pipes between in-line blending valves and outlets should be kept to a minimum in order to prevent the colonisation of waterborne pathogens. So, if it's being checked by building control that might cause issues.

Thanks all. I'm definitely leaning towards option C. The limiting factor will be I don't know exactly where the joists will be underneath yet but I have the option of rotating the bath 180° to offset the other way so I think I'm covered.

I'm fixing an acrylic shower tray to an upstairs bath room floor - moisture resistant chip board floor on posi-joists, all brand new. The surrounding floor tile will be decoupled, probably with DITRA. I currently have the standard tray-sized hole, filled with plywood plus mortar on top design. It occurs to me that this might be overkill, why would I not just run the decoupling mat everywhere and thinset the tray to the decoupling mat? Vertical displacement is not going to be an issue, so I believe i'm really only looking to protect against differential expansion, which is what decoupling mat is specifically for. Any thoughts on this?

I used these on my last bath room which was still fine after 10 years. Is it possible that product quality is an issue here? As in, buying a hotels worth you might go for a cheaper option, buying half a dozen this is not an issue.