pipes through joist

[Yarn]

Hello there. Firstly a big thanks for all my previous questions.

I have an extension which I need to fit with radiators. The CH pipes will need to cross nearly every single joist in the new build.
I was wondering what the best practice was for pipes through joists. Should I drill with a hole cutter or should i notch out?

I would prefer to run 22mm pipe so i suppose this will make the hole bigger. Also since i need flow and return is it worth spacing out the holes / notches.

I suppose there is not much in it, but with such nice new joists i want to make minimal impact on the structure.

Many thanks.

 

[seco services]

What are you using copper or plastic ?
You won't get a length of copper through the centre of joists.

 

[JimCrow]

You will quite easily if the brick/blockwork isn't up yet.

 

[swbjackson]

Have a look at http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Pipework-in-suspended-flooring.pdf

It gives you all you need to know.

 

[Yarn]

Hi swbjackson, i must say i was a little skeptical about the link, but it really did tell me everything i needed to know!


What is the best way to cut a notch in the joist?

Cheers.

 

[kirkgas]

Hi swbjackson, i must say i was a little skeptical about the link, but it really did tell me everything i needed to know!


What is the best way to cut a notch in the joist?

Cheers.

the best way to cut a notch is to drill 2 holes at the bottom corners then saw down to the holes leaving a U shape as opposed to 3 straight sides as this places less stress on the timber,

 

[Nige F]

You will quite easily if the brick/blockwork isn't up yet.

Even if it is up you can take a brick out then core drill the inner leaf for each pipe - whole lengths then go through - refit cores with some gripfill and replace the brick - simples

 

[Geeba]

I've hit this same dilemma... I'm doing a loft conversion and subsequently have a heap of pipes and cable to run through joists including a 28mm gas pipe..

If I'm reading that document correctly I only have 200mm to install all my pipe and electricals? 0.45 from the plate/bearer and then 0.25 back in? and then they have to be at least 3 diameters apart? - with the amount I have to put in its just not possible to get them in... the last thing I want to happen is the building inspector to come round and bin it!

Am I reading it correctly?

The whole extension seems completely over engineered... its crazy 9" joists... some of them have been doubled up and coach bolted...

 

[nickjb]

What is in the approved document is just one way of satisfying building control, and for putting holes in joists its a pretty idiot proof method. If you can prove you design would also be safe and structurally sound than that's fine too. How you prove it can be tricky but and easy option is to ask your inspector what he would be happy with, some are helpful some are less so. If your joists are over sized (which you can check from span tables) then you'll have a lot more leeway with holes and notches.