Advantage of 10mm over 15mm plastic for CH rads?

[Limax]

New to this forum so first a big hello. This is my first question but probably not my last.
Given that there seems very little difference in cost between 10 and 15mm plastic pipe and fittings (15mm cheaper in some cases) is there any advantage to be gained in using 10mm rather than 15mm for the feed and return to radiators?
It's a three bed bungalow and the pipework will be under a wooden floor. I am intending to use 22mm plastic for the main feed and return under the floor and teeing off to copper drop down pipes from the radiators. Probably use 90 degree JG Speedfit elbows to connect to copper drop down pipes. Radiator sizes and length of runs would suggest 10mm as being sufficient. However I don't see the extra flexibility of 10mm being any advantage in this case so I'm thinking 15mm would need less clipping and can only be better from a pressure point of view. Am I missing something?

 

[Agile]

You seem to imagine there is some advantage in using thin tube.

Unless you need 10 mm to thread it through something I can see no advantage at all.

A manifold system with roughly similar tube lengths is largely self balancing but I dont see that as any advantage as I always balance everything.

Tony

 

[Limax]

Thanks for the reply Tony. Looks like I will be using 15mm then. I thought there might be some good reason to use 10mm that I was failing to see due to a lack of knowledge on my part. Thanks for clearing that up.
Frank.

 

[hansthebear]

10mm is easier to work with, and will require less fittings as the pipe can be manipulated by hand, hence cheaper.

 

[namsag]

Plastic under a ground floor hope you dont have any mice or rats around that get under there they will eat through it

 

[Hufty]

10mm pipe great for new build and house refurbs - tack it to the wall with big loops coming out of the wall where the radiators will hide it, connect it all up, pressure it all up, leave site. It's 10mm so the plasterers can dot and dab over it no problem. For second fix hang the rads, cut the loops, use normal 15mm TRVs with 10->15mm reducing elbows. Joiners happy as can get skirting board in no problem, customer happy as you haven't guessed and missed with pipe locations into the floor. Everyone happy until someone wants to add another radiator or move the existing one.

If the walls are already plastered and I can access the floor voids from above I personally use 15mm plastic with copper tails into the rads.

Just to add: manthorpe pipe guides are better than electrical back boxes for where 10mm pipes come out the walls. Plastic pipes buried in plaster should be traceable - I use zip ties to fix metal capping strip over the pipes which also gives a bit of protection against nails or whatever.