[quote author=JohnD  link=1110212496/0#0 date=1110212496]
1. Is there any particular depth under floorbaords which pipes should be laid?  Or is a 3/4" notch still o.k.?

2. End feed or solder ring fittings or doesn't it matter?

3.  Where I tee off under floorboards and one pipe has to pass over another, is it best to have the bend in the flow side or the return side? Or doesn't it matter?

4. Years ago they used to use old carpet around pipe where they passed over joists to stop banging. What do I use now? Lagging?

5. When running my pipes up the centre of the room to a radiator at the far end of it, I assume that,  as the joists are parallel to the wall I am running to, I run the pipe right over the first joist virtually up to the wall (there is a 2" gap between the joist and the wall) then  fit a right angle bend to each pipe and after 2' 6"  on each pipe then come up through the floorboards to the rad.  This will mean that there should be enough give in the pipe to get the rad off.

The reason I ask is that it would be simpler to put my bends in one joist further back, and then run two pipes straight to the rad some 5' apart, but then I assume I would have more difficulty lifting the rad off the brackets for decorating etc. unless there was a very deep cut in the joist indeed, which wouldn't be good practice.   Have I got it right?

6.  Finally, should I lag the hot pipes and c.h., pipe under the floorboards?  I assume this would prevent floorboard shrinkage and heat wastage but have never seen it mentioned.

Thanks

JohnD [/quote]


Some answers.

1: ¾ notch will be fine. (mark the boards so you dont nail the pipes)

2: Doesnt matter, if you are confident enough use end feed as they are cheaper, if you havent done too much soldering stick to the solder ring fittings. If using solder ring dont be tempted to add solder, just heat until you get the nice silver ring round the fitting. TIP: use plenty flux and wipe off with damp cloth once joint is made for a clean finish.

3: Doesnt matter, but give yourself plenty room so you dont need a tight bend, less bends the better.

4: Lag all your pipes anyway. lagging will do fine for creaking and dont cut your notches too tight.

5: Leaving plenty slack from the last joist might give more play, however to get the rad off the play is better horizontally i.e play in pipe side on to rad. I would cut the joist an inch or so for this notch laterally so this play is there(remember the floorboard will need an inch "hole" too.)

6: See 4

Hope this helps.


btk

[quote author=JohnD  link=1110212496/0#2 date=1110239072]Thanks, BTK - very helpful!

As to lagging, any particular type? Polyethylene o.k., or should I go for the old fashioned hessian stuff?

As to giving myself plenty of room, should I raise two adjacent floorboards and put a pipe under each - or just put one either side of the same floorboard?  

Oh yes, knew there was something else -  how long can a straight run of CH or hot water pipe be be before I have to put an 'omega loop' in to allow for expansion?  


Thanks again

JohnD

[/quote]


Dude its 2005, never let me hear the words hessian lagging again. TIP,: Lag the pipes before you install them. then you only have small sections at the joints to lag once its in place.

2 boards, you'll need the room to work at them anyway.

not long enough in a domestic pumped heating system.

you are over complicating things now lol.  

2 runs, flow and return down middle of house teeing off to rads. just like yer m8 said! lol.



btk

Plastic pipe?  Not on your nellie! Quick, convenient and totally unproven in terms of its long term suitability.

Speaking only as a talented amateur I'll carry on soldering.........

JohnD

Here in Belgium it seems to be much more common than in the UK. The impression I get is that in the UK few people have sufficient experience with the stuff to get it working right. I hear once you are aware of it's quirks it's a lot quicker to install.

If I've done my sums right there will be about a kilometer of the stuff concreted into the UFH system of my house - so it better not leak!

plastic pipe can be very good when properly installed. Personally I only use the stuff for very hard to get to stuff, some showers etc. I always use copper and end feed(where possible) i feel that the main advantage with copper is that it doesnt tend to sag and gives a far higher finished look than plastic. I'd never recommend a DIYer to use it as the joints need to be well made and away from things like joists etc where they might get knocked off, remember most plastic joints are push fit and are removed by simply pressing a ring towards the joint, if these are against anything they can pull themselves off(much like a sparkie, lol).

I would only use plastic where it will never be seen, which granted a heating system pipework is never seen. But just not worth it IMO. I would stick to copper specially since its your own house, you might never see it, but you'll always know whats there! Peace of mind! lol


btk

Done loads of complete CH systems in Hep20 barrier pipe, wouldn't use anything else now, had no problems, done complete bathrooms and kitchens with no problems either, no way can you pul off a Hep20 fitting either slimline or the demountable fittings if they are fitted correctly, I dont trust the white speedfit type of stuff though as it doesn't seem as robust, I mix and match copper and Hep20 together with no problems at all.

Yeah i've never had any problems with the stuff either, well if you dont count 'it looks like shït' as a problem.  Loads of clips, formed bends. offset anyone??  Gimme a good copper install anyday of the week.


btk

Who gives a toss what they look like under the floor, wELL I DO FOR STARTERS

Plastic rubbish.

scruff

http://img.photobucket.com/albums/v395/thescruff/Imgp0921-m.jpg

And try this in plastic

http://img.photobucket.com/albums/v395/thescruff/Imgp0990.jpg