rad pipes in a loft..

[ColJack]

I have just spent the afternoon up in my loft space putting that foam lagging on the radiator pipes up there..

I live in a first floor flat with concrete floors FYI..

these pipes have been run over the top of the cross beams..

I am going to re run these in the summer ( so I won't miss the heating ) and need advice..

I want to run them as close as possible to the ceiling below and then put rockwool over them to insulate them..

the pipes from the boiler are 22mm but are stepped down more or less as soon as they go into the loft , is this a problem?
I want to continue them in 22 using reducing tees to tap off for the rads, is this the right wa to do it?

at one point the pipes turn at right angles to the last rad with elbows, I want to put reducing tees in here instead and have a small dead leg in case I get round to swapping the kitchen into the spare room.. ( which is the other side of the hallway..

 

[ChrisR]

15mm is ok as a rule of thumb for about 4kW of heating if not more than several metres.

 

[Bahco]

I want to continue them in 22 using reducing tees to tap off for the rads

Good idea as your system will heat up a bit quicker but don't fix what is not broke.

I want to put reducing tees in here instead and have a small dead leg in case I get round to swapping the kitchen into the spare room..

Not sure what you mean

 

[ColJack]

the pipes come left to right from the existing boiler in the kitchen, then turn towards you for the last rad in the bedroom..

I want to put tees in when I change up to 22mm so that at some point I can change the kitchen to the spare room to the right and carry the pipes through without having to sweat the elbows off and change to tees later..

they will be capped off after about 6 inches or so..

I understand that this creates a dead leg which is generally a no-no but I'm hoping that being that short is not a problem..

I am even willing to put compression fit gate valves and a loop so that it can be filled properly..

 

[Bahco]

Don't loop them together but leave the stubs as short as possible so you can extend at a later date