Riverside Cottage 6

[Tim Lamb]

Now stripping out plumbing and electrics.

Is it a hanging offence to use a 15mm compression stop end on a gas pipe?

There is no provision for locking the supply shut off valve in the outdoor meter cabinet. The 15mm is T'd off from the boiler feed and runs across ceiling joists which are coming out.

Also Megaflow experience.. There is ample mains pressure here 4-6 bar so the system can run at the designed pressure. I am considering pipe routing (to minimise hot water arrival times) and wonder if 15mm gives adequate bath fill flow rates.

Also any thoughts about plastic piping for plumbing other than underfloor heating? Noise, reliability for hot supply etc.

[Fredxxx]

It's a hanging offence not to cap a supply!

Compressions can be used in pipework as long they're accessible.

Mains pressure - yes.

I avoid the stuff, but is quick to put in place. Others here might have more experience than me.

[Peter Johnson]

At a B&B where I knew the owners I commented that drainage from the handbasin was slow. Then I realised that the culprit was inadequately supported plastic pipe that distorted when hot water ran through it. (They didn't put me in that room the next time I stayed there.)

[John Rumm]

No. Compression and capillary solder fittings are acceptable on gas.

At those pressures (although note that an unvented system will normally have a PRV bringing the operational down to around 3 bar) you should still get fast fill times. What you may find is you get a bit more noise, and a more notable drop off in performance when other users in the property are drawing water.

See

If assembled with care, then performance and reliability seems ok. For some applications its a massive time saver on installation. Main downsides are it looks clunky and the fittings are pricey (but offset by lower pipe prices). Also has the advantage of being easier to dismantle if needs be.

[Tim+]

With the proviso that compression fittings must remain accessible surely?

Tim

[Tim Lamb]

This will be in plain sight under the boiler. Eventually the boiler will be replaced/repositioned by a professional:-)

[Tim Watts]

I *believe* that's fine as long as it is accessible and not under flooring or in loft spaces - ie it's out in the open, inside a room or outside the house.

Otherwise it should be done with a solder cap.

I put a 22mm compression stop on mine just outside of the meter box, all outside.

[Tim Watts]

And accessible pretty much means "on show" with gas, not "well, maybe, if I prise a floorboard up under this fitted carpet" like electrics.

[Tim Lamb]

Yes. There are a few potential *gotchas* in there.

Annual maintenance. Any legal implications or professionals involved?

Careful pipe routing should minimise drawoff pressure variations ie. separate feeds to kitchen/bathrooms/basins.

The house is chalet /bungalow so header tanks not really practical.

20l/min could be tricky but I might be able to enlarge the main supply pipe as part of another project.

I am planning boxed in ducting for the main runs. To facilitate first floor underfloor heating I am going to cross batten the joists. Cold/drinking water runs may need care:-)

>

[John Rumm]

Yes generally (although definitions of what is "accessible" can be open to interpretation)

[John Rumm]

Its worth maintaining obviously (and the required work is not onerous).

If using a pro, one should check he has the qualifications in unvented cylinders.

Hot water storage cylinders come under building regs (unvented always did, and vented was added more recently), and so fitting one is a notifiable job etc - as to how often that is actually done in practice I don't know, but would guess its up there with the number of standalone part P applications ;-)

Yup that can help - as would having roughly equal flow resistance on the separate runs.

Yup, had the same problem here - bungalow converted to chalet style, but with a traditional vented system originally. The result was woeful hot water performance on the first floor (i.e. if you lifted the shower handset on the bath taps more than a couple of feet about the bath, the flow stopped!)

Yup well worth doing if going this route - flow rate will make or break the experience.

;-)