Plastic pipework

[dennis]

To someone that has done a heating system it would suggest a rad and a manifold.

[Dave Plowman (News)]

Ah. Another bodge. Say no more.

[dennis]

What's a bodge about doing it correctly? Do you know anything about modern heating?

[Dave Liquorice]

Manifold implies microbore implies bodge...

Can you get microbore plastic?

[Dave Plowman (News)]

With microbore and manifolds?

I do know nobody in their right mind uses those unless forced to.

[Doctor Drivel]

Plastic is problematic. Proper people don't use it unless they have to.

[Dave Plowman (News)]

True. But not so old I can't hear the noise microbore makes.

[dennis]

> Can you get microbore plastic?

people are just too old to learn. ;-)

[dennis]

You are just old. ;-)

[ARWadworth]

So you have done a CH install with a manifold (of course these are not cheap) and run microbore to the rads. You might save on a few connectors but the manifold option wastes pipe in most cases.

I can see why in a small new build it may be easier to do this, but I would not want it in my house.

Adam

[ARWadworth]

They might gain access to my van where the stuff I need is or my shed where the stored stuff is! So far only the van has had its load lightened and that was while it was parked up at work. Two lengths of 15mm copper and a new back window for the van. I do not worry about them lifting floorboards in my house and removing the copper.

You would not say that if you had to get a pipe down a studded "cardboard" wall with your head stuck in the corner of a well insulated loft to supply an electric shower without damaging the tiled bathroom wall.

Why do people paint the copper tails? Polished copper ones looks better IMHO.

The option to growing old is to live for ever or die trying

Adam

[Ed Sirett]

In your own words... To come out with that comment I question your experience in using plastic pipe.

[Clive George]

I'm guessing you're replying to DD here rather than Jim Alexander?

cheers, clive

[Ed Sirett]

It would be useful to review the various type of pipe and fittings that are currently available.

Copper Pro - long history of use. can be bent into nice shapes. Con - expensive and very prone to theft until fitted. needs corrosion protection. Plastic - PB. (PolyButylene ?) Pro Can be cabled through joists lower heat losses.

Con unsightly - sags when cold and more when hot. needs a few but relatively expensive joints. negative reaction by some. not usable for gas.

Plastic - PEX (Crosslinked i.e. stiffened PolyEthylene?) Pro lower heat losses than copper Con can't easily be "cabled" as per PB.

Stainless Pro - corrosion proof smart Con not easily soldered. not suitable with push fits. As for the joints this is my take. Criteria: Ease of making initial joint. Chance of a good joint without further work. Neatness, long term reliability of joint, cost, demountability.

The joints are endfeed, JG Speedfit, Cuprofit, Techtite, Hep2o, compression (BS 864).

Obviously endfeed is only on copper.

Ease of initial jointing Hi to Lo (IMHO) Compression (unless very limited access), Hep, Speed, Tech, Cupro, Endfeed.

Chance of good joint Hi to Lo (IMHO) (highly dependent on experience and position of joints). Endfeed, all push fits, compression.

Neatness Hi to LO (IMHO). Endfeed, Techtite, Cupro, Compression, Hep, Speed.

long term reliability (leakage) (IMHO) Hi 2 Lo Endfeed, Metal pushfits, plastic pushfits, compression.

Ease of demoutability/repair (HI 2 LO) Speed, compression, Hep, Cupro, Endfeed, Techtite.

The list is not exhaustive, but I think it is fair.

[Ed Sirett]

[e-mail]...

Sorry, Adam, I with dennis on this one.

When you are installing Ch with a suspended floor construction from scratch, you really are looking at an elbow under each rad tail and one length of PB pipe to each end.

Using cable insertion tools to get a rope under the floor and then drag a pair of 15mm "Heps" from one side of the room to the other.

Obviously there will be other fittings involved.

Overall I'd say that the the material cost is now evens overall the big saving is installation time.

[Ed Sirett]

No. implies bodge... Maybe, maybe not.

Yes.

Typically say you were doing a first floor flat.

you'd put the rads in each room and you bring the pipes to the passage way. 2 or 3 rads would join using 15mm equal tees. A couple of groups of

2 or 3 rads would make 22mm.

Or you might have a 22mm 'backbone' and use 15mm side branches.

If you had four rooms come to together you might consider and 22 to 4x15 manifold but there again you might just roll-your-own with T fittings.

[Ed Sirett]

20mm is only the equivalent of 15mm PB and is (IMHO) much stiffer than PC pipe. The fittings for the MDPE are enourmous even next to Speedfits

[ARWadworth]

It sounds like massive overkill for a semi. I do not have a problem with such a design (apart from the fact I hate manifolds). Could/did the costs of the install get a full pay back on the fuel bill?

I do not know when plastic started to be used. Was Acorn one of the first?

Adam

[dennis]

You wouldn't want something that is easy to install, maintain and is probably more reliable? Why? I bet you are one of those die hards that thought coax Ethernet was/is better than TP.

[dennis]

Yes, manifold to 15 mm, 15 mm to five zone valves, zone valves to rads and cylinder, return to manifold. What is the problem? Do you think five zones with timer stats is overdoing a semi or is there something else? It wasn't plastic BTW as plastic wasn't around when I first did it.