Few plumbing questions

[D4N1EL]

Hi,
Is it ok to change a single panel radiator for a smaller double panel radiator?

I'm pulling mu ceiling down in my living room, I'm going to run my central heating pipes in the ceiling (and reposition my radiator) the pipes will be coming down the next corner, i plan on using plastic 22mm pipe, I'm guessing 22mm is the internal diameter so would a 25mm hole be big enough? I will be getting a pro in to connect it up and do pressure checks ect, ill just be drilling my joists and fitting pipes to try and keep the price down abit.

Thanks

 

[Hugh Jaleak]

Changing a single to a double shouldn't be an issue but unless it's heating half a castle then 15mm pipes should be enough!

 

[Madrab]

ill just be drilling my joists and fitting pipes

Just be careful where you're drilling your joists, hole positioning, sizes and spacing is all critical to avoid weakening and to keep within building regs

 

[D4N1EL]

I was told by the guy who fitted my central heating the pipes that run around the house are 22mm and the pipes that T off to the radiators are 15mm. Wll a 25mm hole be big enough for a 22mm pipe or should i go bigger?

Ive read different things on different forums about measurements and it all seems abit confusing, but i think i have to drill between 04 and 0.7 of the width of the room from the supporting walls and the holes have to be atlease three times the size of the hole apart, just to make sure i dont do to much damage im going to add abit of extra wood to each joist around the hole, not sure if it'll make any difference but it cant make it worse.

 

[Madrab]

http://www.stevenage.gov.uk/content/15953/24595/24598/GuidanceNote22-TechnicalNotchingJoists.pdf
There's a link daniel that gives you the calculations you need as per the building regs. Don't worry about the extra wood, no need, as long as you stay within the guidelines then should be fine.
25mm hole should be plenty for 22mm pipe.
BTW, You must use a barrier type pipe if it's for CH.