MortarThePoint

If I cost up my staircase in parts, it works out as about £1600. I have just had a quote from the same company that supplies the parts and its £4500. I know there is work in the cutting and assembly, but it doesn't feel like £3000 worth. Without the CNC machines, it feels like it would take an experienced joiner 1-2 days to cut everything and then perhaps similar to assemble to the same state that you receive a staircase in. That means you're looking at perhaps £2400 compared to the £4500. Mass production should make the staircase manufacturer cheaper. What am I missing?

I might be able to do something a little similar passing the 50mm shower waste underneath the toilet 110mm and the having it change to 110mm for about 500mm before the using a Y on its back. A challenge is that the Toilet pipe ends up centred about 225mm above HCF at the junction so with the about 2.0m of run that makes it 225mm + 2.0m * 18mm/m = 261mm. A bit more to allow fall between Y and the 90 bend exiting the room makes for 270mm. If screed is 60mm and if tile adds 10mm that would put the pan connection at 270 - (60 + 10) = 200mm above tile which is about 20mm too high for most toilets. Closer than I feared it might be though. The bath pipe could offset vertically near to the boss so as to slop flow towards the bath. Can I be sure the boss wouldn't get blocked with poo?

In terms of the whole room, here's what I am up against: Room 2.7m x 2.5m ~60mm screed depth

Cross post sorry, a good length of 110mm before the tee seems sensible. Not sure I can manage that though.

Are you thinking like one of these laid on it's back as shown here

No it is sold, eg on Amazon, and I can see how OK if waste pointed up

Pretty clear cut then I had concerns too, is this better

I need to get a toilet pipe and shower waste (plus others but similar principle) out of a room without passing much below FFL. My only thought is to do something like the attached image. It doesn't feel ideal, but is it a no-no? The exit of the bend would then pass through the wall and to a bend 90 heading down. I want to avoid joining the waste pipe the other side of the wall as that is outside and will increase the visual impact.

Why would it have to be big and flat. If anchored the staddle stone to the concrete pad and the post is anchored to the staddle stone I'd hope it can be something like 200mm x 200mm x 200mm. It would be better if I could find a rebar post anchor with a longer piece of rebar as then it could pass all the way through the staddle stone and be structurally connected to the concrete pad. I'd prefer something that doesn't end up visible, but I could bolt one of these to the top of the Saddle stone: https://tradefixdirect.com/post-supports/simpson-concealed-post-base-1-1

The post wouldn't be gripping the rebar so should there be some form of retention there? Something like the bracket below. It's rebar would ideally be longer if wanting to go all the way into the main pad. https://www.amazon.co.uk/support-bracket-adjustable-Terminal-90X130X8/dp/B01LZGXEPV/

Looks like it's worth considering stainless a steel dowel: https://jbstone.co.uk/masonry-supply/staddle-stones/

I'm building a Loggia across the back of the house and to this point assumed I was going to use a galvanised post base, and settled on PBH120 because it it higher than the cheaper PPA and PISBMAI alternatives. It feels like a good choice to have the bottom of the timber post >150mm above ground level to avoid rain splash in a similar way that having house DPC there does. I have cast 600mm x 600mm concrete pads on top of slightly larger pads that go all the way down to 1.5m. I have put the top of that pad 225mm below house DPC to allow: 150mm patio to DPC 50mm paving slab height [or 63mm] (could be thinner slabs on a deep (40mm) mortar bed 1:80 patio slope so based on 1600mm total patio width that yields 20mm. 5mm slack If using the Galvanised post base, the plan is to bolt them directly to the concrete pad and leave a 300mm x 300mm hole in the paving that I then fill with pebbles. I am a little worried that the post base may rust in time though, so that made me think of sitting the post (or even a shorter galvanised post base) on a concrete block of some sort. I have now learnt this is called a Staddle Stone and the post normally sits directly on this by means of a piece of rebar that is cast into the concrete block then sits in a hole in the base of the post. This seems like a nice approach. Discussions with @Gus Potter identified that I need to think carefully about lateral loads due to things like logs getting piled against the posts. I am not sure which of the R numbers in the table below of post base capacities reflects this direction of loading. How is this dealt with when using a staddle stone? It occurs to me that I could have a piece of rebar (e.g. T20 = 20mm dia.) passing all the way through the staddle stone and into a hole drilled in the concrete base. I expect I need a bed of mortar under the staddle stone and perhaps to resin the rebar into the concrete pad (and/or) staddle stone. Is that how it's done? Will there be enough lateral load capacity in such an arrangement though? The post may well end up being 150mm x 150mm Oak and I guess the rebar would pass into in about 75mm or perhaps a bit more. https://www.strongtie.co.uk/en-UK/products/heavy-duty-elevated-post-base-pbh

I drilled an oversized hole to allow a bit of wiggle and will pack it with acoustic roll when done. Flexible / offset pan connectors could give me extra wiggle room too.

An adaptation to move it closer to the wall. 210mm + 36mm for a 20mm or 40mm Offset Rigid WC connector (or MACFIT 20mm / 40mm) and minus ~16mm for plaster and tile give >=230mm for back of cistern to wc connector distance. That may allow some close coupled, but certainly plenty of traditional style options. (a straight option is unlikely to work but is MAC-1 . About 200mm between the centre line of the loo in this room and the higher part of the box-in. That allows the pan to be up to 400mm wide at that point which is unusual (most narrower than that at their widest). Still another boss to use for a 32mm pipe. Also a second new boss to use below the floor for a 50mm shower waste.

This is where I am ending up I think. Not using the 45 degree double branch but a couple of single branches (SP190) instead. The one facing the floor is to be rotated 90 degrees to face sideways. This does increase the size of the box-in, will need to extend 820mm along the wall behind one of the toilets, 820(l) x 200(w) x 240(h) / 360(h) . If I need to I can attach a smaller AAV to the boss on the horizontal branch. It leaves the socket for the first toilet about 205mm plus the distance between the first branch edge which if I don't use a soil pipe offset or widen the hole is 70mm from the wall. If I then use a compact offset pan connector the toilet's spigot needs to be 205+70+31=306mm from the wall. That won't work with a Close Coupled toilet (unless a box-in behind toilet all the way up) so will have to be a more tradition style like the one below. If I don't use a soil pipe offset, there is possibly room for a 3-way boss to connect the other en-suite's shower/basin (40mm) to. If not it will mean I have to have an ungodly 3no. bend snaking to get it to a boss below the HCF. The side boss (facing the wall) of the first branch could have the macerator connected to it. I wondered about using an access 90 (SP169) but fear it would create turbulence in the flow from the second toilet which wouldn't be good. Hopefully a blockage there is unlikely(?) Plan View: Cove Low Level Toilet incl. Lever Cistern + Seat

I guess this is a possible solution to cross flow. Rodents shouldn't be problem as we are having a sewage treatment plant so a closed system as far as a rate is concerned. Anti Back-Flow and Rodent Barrier Valve https://mcalpineplumbing.com/wc-connectors/wc-connector-accessories/arb-1-anti-back-flow-and-rodent-barrier-valve

The toilet the other side of the wall would be after a couple of 90 degrees so I think unlikely to receive any gifts from the ne in this room. It's the other way that I'm more concerned about as the pan would be directly connected to the branch. It could have a small vertical offset though to help

We're changing the layout of the bathroom (see images below) to move the toilet. There is a hole in the concrete floor that is poorly placed but needs to work. I originally planned to use a Double Branch (SP230) to route the pipes to the two toilets that need to be served by this stack. That was a bad plan due to the resulting size of the box-in, but we're looking to move one of the toilets now anyway. A Corner Branch (SP232) would work a treat, one socket heading to the wall and one along the wall, but the are fabricated to order. Even with the corner branch, the socket pointing at the wall would be a bit too long so need a large hole in the wall to work. What I have arrived at is in the diagram below. It's a bit weird in that it involves mounting a double branch at 45 degrees. The concern is around cross flow. Is this a crazy idea of something that happens? Room Layout Change: Original Plan:

Hmm, screed is actually 52mm and pan connector is 180mm. Also A and B are the wrong way round in targets

I have spoke to both Floplast and Wavin (OSMA) and they both say that all their pushfit boss adapters (e.g. SP11 or 2S399) are designed to be used with either pushfit pipe or solvent weld pipe. I shared the same concern as @markc, but it seems to be fine. Floplast and Wavin (OSMA) also both said that it is OK to solvent weld ABS pipe into their PVC-U bosses (in the case of OSMA that may require an ABS solvent weld coupler as the boss is the same ID as the pipe). I queried that the materials are different, but both said it was fine. I was surprised. I think I feel more comfortable using the pushfit boss adaptors onto the stack as I am a bit of a commitment-phobe.

Can you use a solvent weld (SW) pipes in the pushfit (PF) boss adaptors used on the soil stack? The adaptors come in 32mm, 40mm and 50mm sizes so is it the same answer for all? As SW outer diameter (OD) is larger for each I guess there is an element of if you can get it in its OK as long as the BCO is then not going to have a problem. Second question is to if making a solvent weld joint between the boss adaptor (PVC-U) and pipe (ABS) it is a mix of materials. Does that work OK for the weld and is standard? Basic stuff, but if you don't know you don't know. I do know you mustn't mix SW and PF pipe and fittings normally and you have to use an adaptor if you want to. Pipe SW OD PF OD 32mm 36mm 35mm 40mm 41mm 40mm 32mm 56mm 53.5mm Numbers from Floplast website drawings

Another wildcard option is to use a ring-seal 3-boss below the offset, but that lowers the shower's connection point by about 100mm. That could be OK by using two 90 bends. That might be a bit brutal for the shower flow. An alternative would be a 90 elbow out of the boss to a 45 elbow, but that increases the box-in locally Maybe 3no. 45 elbows?

This is ending up as a pretty busy stack: OSMA 3-boss as shown in photo at floor level OSMA 3-boss at ~500mm as an emergency connection point for the utility sink if there is a problem with its independent underfloor drainage OSMA 3-boss at near ceiling level (GF) for shower(50mm) Floplast 45 solvent bend for offset Floplast 45 solvent bend for offset OSMA 3-boss at screed level (FF) for bath&basin(40mm), shower&basin(40mm) Floplast Double Branch for connection to two toilets and one toilet_macerator_pipe(32mm) AAV in top port of double branch All the 110mm up to the Double Branch is ending up as solvent weld since the OSMA 3-boss is solvent weld and I need the offset done in solvent weld to accommodate the necessary verticals. The horizontal offset is only about 80mm, but moves the stack further from the corner allowing an OSMA Tight Bend (4S160) to fit in one side of the Double Branch. Rodding should be possible by removing the AAV and will hopefully pass easily through the offset. I'm a bit nervous having solvent weld all the way up to and including the bottom joint of the the Double Branch. I could move the offset below the ceiling boss and do it in pushfit, but that would increase the size of the box-in in GF (300mm x 220mm -> 380mm x 220mm). Alternatively, I could add an otherwise unnecessary pushfit joint just below the ceiling OSMA 3-boss. What would you do. Not worry about it, add an extra pushfit joint below the ceiling OSMA 3-boss of add a pushfit joint between the offset and the floor level 3-boss? The code in the table is (lower 3-boss) - (bend) - (upper 3-boss) and Ring(F) is a Floplast ring seal 3-boss and Solvent(F) is a Floplast solvent weld one.

I am having a 'back to wall' toilet which is going up against a box-in that contains the concealed cistern (~100mm deep). Behind the cistern is a blockwork wall through which I will be passing the 110mm soil pipe. I think this will leave about 125mm between the back of the pan (and its spigot) and the blockwork. A flexible connector like the one below feels like a good option to connect the pan to the soil pipe if the soil pipe extends only a little way past the surface of the blockwork.. As I haven't tiled the floor yet, I can't be sure of the exact height, but should be able to get the soil pipe to within about 10mm of where it should be. How much vertical offset could a flexible pan connector like this afford me? I'm wondering if I should drill the hole in the blockwork oversized (127mm instead of 117mm) just in case. https://www.screwfix.com/p/mcalpine-flexible-straight-wc-pan-connector-white-100-160mm/6458P https://mcalpineplumbing.com/wc-connectors/flexible-wc-connectors/wc-f26rc-straight-flexible-wc-connector

https://condell-ltd.com/lintels/catnic-lintels/catnic-cavity-wall-lintels/catnic-cg90100-cavity-wall-lintels Minimal price difference for 1800 to 1950. 3300mm lintel looks more than I expected so perhaps I'm out of touch with prices.