New bathroom

[Jonathan George]

I'm about to embark on an attempt to refit my bathroom. I'm happy doing the plumbing myself, but I'd quite like a bit of reassurance that my plan will work!

There is currently a bath, basin and toilet. I'm going to turn the bath round, and possibly change the wall the basin backs on to (although it will stay in the same corner, so this shouldn't be a major job). The toilet isn't going to move. I'm also planning on adding a power shower. I don't have to worry about replacing the toilet, as I'm having my soil stack completely replaced and the guy who's doing that is going to put the new loo in at the same time.

The basin and bath both have mixer taps (monobloc for the basin), and all cold water is fed from the rising main. Apparently this is against building regs or something similar, as there are no double check valves or similar. Is this correct?

I've got a cold water cistern in the loft and a hot water tank in the airing cupboard, next to the bathroom. Assuming the previous paragraph is correct on the cold water front, I was planning on taking a branch from the cold water feed to the hot water tank and using this to supply cold water to the bath and basin taps, leaving the toilet on the rising main. The shower installation instructions say that I should have a separate 15mm feed from the cold water cistern to the shower, and a 15mm feed from the hot water tank taken off below the join to the vent pipe and before any other draws. All sound ok?

The exising wastes are metal and from measuring the diameter appear to be 1.25" for the basin and 1.5" for the bath. I'm therefore assuming that if I can cut them off square with a hacksaw (which could be easier said than done, as they are right against the wall, I can use standard 32mm and 40mm pushfit connectors to join them onto new plastic pipes and then use solvent weld/more pushfit depending on how confident I'm feeling. Does this sound ok? And if so, is it necessary to strip the paint off the old wastes before I do it?

What's the best way to strip old paint off pipework, especially if access is limited (why anyone would paint pipework that's right at the back of the airing cupboard, I have no idea).

Hopefully that all makes sense. All help greatfully received!

Thanks, Jon

[Gordon Henderson]

I'm about to do the same!

Hey - You are not secretly employed by my SWIMBO are you? Thats exactly what I'm about to do!

Not having a new soil stack, but installing a new crapper though.

My toilet cistern is fed from the mains and all else comes into the bathroom on 22mm pipes (15mm Teed off to the sink) I have *no* check valves anywhere in the house (apart from the kitchen which I replumbed last year) So I'm going to have to drain the entire system at least once in the process of re-doing it all )-: I've also got to turn a radiator into a towel rail which will entail draning the CH system... Good job we're having such a nice hot summer...

Everything I've read and been told suggests that taking a separate feed off the cold water tank and a separate feed out of the hot water tank (via Essex Flange) is the way to do it rather than T into the existing pipes. This is what I'll be doing. The pump I've ordered has 15mm connectors, but the run to the bathroom (2 rooms away from the tanks) is 22m. I don't see this as being a real problem and theres no-way I'm going to lift 2 rooms worth of pipes to change it...

I'm all plastic as far as waste is concerned... Angle grinder might be eaier to cut the pipes with... I used pushfit in the kitchen stuff and it's worked a charm.

Steel wool & elbow grease...

Hope it all goes well for you!

We've already spent too much on bits & pieces, (and blew the budget on a fizzy bubly bath thing), but what the heck, it'll last us many years hopefully.

Gordon

[John Rumm]

That depends. Many mixer taps do not actually "mix" as such - they squirt the water from each supply out of different (often concentric) spouts such that the mixing happens after the tap. If yours are like this, there there is no problem.

If you have taps that mix internally (as some of the older designed did) then it is probably going to be much simpler to install a double check valve on the cold pipe feeding each tap. These are not unlike a straight compression fitting (bit longer) and are fitted in exactly the same way

- chop a bit out a pipe and stick it in. (Not sure why, but some folks seem to think there is some big mystery to double check valves)

Yup - you should install the dedicated cold feed for the shower so that it is sighted a little lower in the cold cistern than the feed that goes to the hot water cylinder. That way if the cistern gets drained it is the hot water that stops flowing first!

You may find this joint is better made with a plastic waste compression fitting rather than push fit, since the matching of the exact diameter is slightly less critical.

Heat with a blow torch, then wire wool.

[Jonathan George]

Thanks for that. One more question. If my new cold feed for the shower has to come off the cistern below the existing one to the hot tank, how do I make a new hole in the tank without flooding my loft! Also, how important is the thing about putting it lower down - the existing one is pretty low down so there isn't that much more space.

Thanks again. Jon

[Bob Mannix]

You have to empty it with a jug and a bucket. It only needs to be just below so that the top edge of the cold is level with the bottom edge of the hot outlet. It depends not only on who is using the shower but on who might in the future - a shower that goes scalding hot generally makes people panic and ask for more cold, sometimes they don't think of just shutting it off and they get scalded. A shower that goes freezing cold just makes them cross! You have to cut a hole anyway, so best to try and get it in the right place even if it does mean 10 minutes with a jug and bucket.

[Andy Hall]

Another approach if the existing outlet is very low is to cut another higher up and connect the existing pipe to it, then use the lower existing one for the shower.

In terms of cutting the hole, a decent hole saw is important. The type with several thin concentric blades where you select one to use are fairly crappy. The type with a mandrel where you then buy a cutter of the correct size are very much better. You can also get electrician's and plumber's sets of these which are cheaper than buying separately.

.andy

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[Jonathan George]

Yes, that did occur to me. However, the existing hole is on the same side as the connection to the rising main, and the shower installation instructions say (several times) that the shower feed should be connected on the opposite side to reduce the chance of air being drawn in. Is this really a problem?

Thanks for the holesaw advice - the last thing I need is to be making an arse of drilling into my water cistern. I'm kind of used to diy jobs taking

4 times as long as I originally intend (since most of the stuff I do is the first time I've tried it) but having to spend hours in the loft trying to repair a bodge would really mess my day up...

Jon

[Andy Hall]

I think that what they are saying here is that if there is a silencing tube on the float valve it will have an air hole to prevent reverse siphoning if the mains supply fails. If there is a fair flow of water then you get air bubbles into the tank at the bottom of the tube.

I would take a look with some taps running and see what it looks like.

.andy

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