Shower pipes chased up external wall or above tiles?

MarcusMaximus · 28-09-2025 01:13PM #1

As the title says. At the moment they are chased in but I had to go quite far into the wall to get them to come out again at 180 degrees to go down into the shower inlets. I have insulated them (15mm pex) separatey with ThermaWrap and then put them both into a tube of 9mm Armaflex. They are on top of 18mm thick styrofoam insulation in front of the blocks.

There are other elbows behind the visible ones to make the first 90 degree turn. The stop ends are only temporary til the shower goes in.

There are a few issues with this:

The effect on pressure / flow of using 3 speedfit elbows (+ inserts) per pipe. One more brings them up from the floor.
The hidden elbows could be a potential problem if they ever leak.
External wall - enough insulation on pipes?
Bulky fittings might protrude a bit too far or not fit into back of shower unit, though I did measure all that and they seem just about ok.

If I run the pipes up over the tiles that would solve all these issues. The problem is we don’t really want them to be visible, even in some sort of trunking, so would prefer to hide them in the wall. I know another option is to build a false wall and put them behind that but then we’d lose at least 40-50mm of space, which would be significant in a small bathroom like this.

So I’m wondering what folks would think is the best thing to do here. Thanks.

10-10-20 · 28-09-2025 10:53PM

I think I'd just go with what you have, its most likely perfectly functional and the insulation is already well above what you need for an external wall.

Is it feeding a booster shower or what type of unit is intended?

MarcusMaximus · 28-09-2025 11:42PM

That’s good to hear thanks as I was concerned about the pipes freezing in winter. I checked the flow and they both seem quite strong, however the pressure measured lower than a copper pipe on the same circuit which feeds the toilet cistern. It has no elbows, nor inserts obviously.

I have a couple of cold forming bends on order which might enable me to ditch the rear elbows. Just to clarify, there are 3 elbows on each pipe, not 4 as point 1 above might suggest.

They are feeding a power shower, the type that has an inbuilt pump but doesn’t heat the water.

MarcusMaximus · 24-10-2025 10:24AM

Just coming back to this before I tile the wall. I'm a little concerned about a weak spot of insulation around the elbows at the rear. I wrapped them as best I could with ThermaWrap but there wasn't enough room to put them into the Armaflex, though I did put offcuts on the top and in front of them. They are also sitting over the 18mm styrofoam which is against the block and are surrounded by the normal 50mm styrofoam in the wall.

Does this still sound like enough insulation?

ted1 · 24-10-2025 01:17PM

what’s the cable for ?

MarcusMaximus · 24-10-2025 02:03PM

It's for a power shower. Why?

MarcusMaximus · 25-10-2025 10:15AM

I'm going to apply some low expansion foam into the cavity around and behind those elbows. Hopefully that should improve the insulation without having to take the backer board off. Good idea or avoid?

ImTiredOfItAll · 06-11-2025 11:50PM

There are better options for elbows than the speed fittings if you are worried about pressure. Each elbow in effect reduces the head of pressure. Something like soldered elbows don't reduce the head height anywhere near as much as speed fit.

Head height probably won't be an issue as it's going to be a power shower. Hope you go for the Triton Novel SR Silent running thermostatic power shower. Best power shower in the pump in a plastic box type of thing. Next step up would be a dedicated pump in the hot press and a bar mixer with rain head

MarcusMaximus · 08-11-2025 02:18PM

Thanks for that. I've committed to the elbows at this stage, having put the backer board up and tanked everything. Hopefully what you say about head height not being an issue will hold true! I did check the pressure/flow on both pipes at the inlet points and it seems pretty healthy.

Incidentally I didn't put any spray foam around the elbows as was advised not to as it might adversely affect the joints.

Yes another member recommended that shower as well in an earlier thread, however I decided to stay with the one I originally bought which is the Mira Vigour as it has the dual head and the piping has been installed to accommodate it. So once again it's too late to change it now, unless the pipes could also fit the Novel but I doubt it. Different inlet system afaik. Unless I took it all out and re-did it! I think not..

MarcusMaximus · 08-11-2025 02:56PM

Another issue I have is even though I fitted the shower tray level and have checked it several times, water is pooling on the side that has the drain. I have read that apart from it not being installed level, this can happen if the tray was not moulded correctly. Also that new trays can do this for a while before they settle down. Just wondering what anyone thinks. Should we just live with it (not a huge deal), try and exchange it for another one or is there a way of fixing it? I've tried slanting it very slightly in the other direction but then the pools just move to the side, though I could experiment a bit more with this.

Edit: Actually I've just realised that when I was fitting it I had to put something on each corner to raise the spirit level because the sides weren't flat. They went up a bit in the middle on all 4 sides so the level could dip a bit to left and right. So either the tray was designed that way or else it is warped, though it's strange that it's the same over both the length and the width. Now it was stored for several months, including over the summer, in a room with a south-facing window, although I made sure not to have it too directly in the sun. So being acrylic, maybe it went out of shape a bit?

MarcusMaximus · 08-11-2025 04:35PM

I've just read the reviews of this tray and they all say the same thing! So it's obviously a common fault. Gonna get on to B and Q about this.

Here are the reviews if you scroll down to the bottom of the page:

https://www.diy.ie/departments/goodhome-vorma-gloss-white-rectangular-centre-drain-shower-tray-l-760mm-w-1200mm-h-40mm/5059340424057_BQ.prd

10-10-20 · 08-11-2025 05:53PM

Yes, that annoying as hell. I'd fully expect that it drains completely.

Wasn't there someone on here who had to get it replaced 3 or more times just to get a functional one (in about 2019, I think). Think the last one came from the manufacturer directly.

MarcusMaximus · 08-11-2025 09:11PM

Yeah especially after spending ages levelling it as best I could and making extra supports for it and so on. Anyway, I brought it back and exchanged it for a much better quality one made of marble mixed with resin. Weighs a ton but hopefully will drain properly. I really don't want to be back and forth to Liffey Valley multiple times like that unfortunate person!

ImTiredOfItAll · 09-11-2025 05:02PM

https://www.boards.ie/discussion/comment/123971960#Comment_123971960

That's such a pity. You could have bought the superior Triton Novel SR Silent running thermostatic power shower for around €300 & Triton Dual rain head for €160. Between quality Shower with 2 years parts and labour warranty compared to the 12 months for the Vigour. Triton rain head is a better quality one too. Proper chrome shower hose. Mira use a cheap plastic hose.

I know you are committed to the Mira. I'm posting this so people reading in the future don't make the same mistake 👍

rje66 · 09-11-2025 05:16PM

https://www.boards.ie/discussion/comment/123932822#Comment_123932822

JJust Curious, is that cable heavy enough for a power shower??

ImTiredOfItAll · 09-11-2025 05:25PM

https://www.boards.ie/discussion/comment/123975122#Comment_123975122

Power shower runs off a 3 amp spur. Light flex is all that is required. In fact, if you use heavy cable, the cable won't fit into the connection terminal on the shower

MarcusMaximus · 10-11-2025 12:24AM

https://www.boards.ie/discussion/comment/123975122#Comment_123975122

Yeah as @ImTiredOfItAll said, it doesn’t need a heavy cable. The manual says you can use up to 2.5mm and the minimum is 1mm. That is 1.5mm. There is also both a 3 amp spur and a dedicated RCD, both outside the bathroom.

MarcusMaximus · 10-11-2025 12:44AM

https://www.boards.ie/discussion/comment/123975081#Comment_123975081

I hear you and maybe that would have been a better choice. It certainly seems to be very highly rated here on Boards. In my experience with household appliances of all sorts though, once they make it through a year or so they’re generally fine for their expected lifespan. That’s why I never buy extended warranties - any faults will show up early enough to catch them under the original guarantee. YMMV of course.

I don’t think it’s quite a ‘mistake’ though. We have an old Mira Event in the downstairs bathroom that has been running flawlessly for years so hopefully the Vigour will be of similar quality. Time will tell. Unless as I said before I change it before it is installed. Chadwicks were prepared to take it back but that was a good while ago. The necessary change to the existing plumbing is what’s putting me off the most, given it is all installed. I will take another look at it though and thanks for the recommendation.

Shower pipes chased up external wall or above tiles?

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