Putting down copper pipe & joists

[wandertheworldtoday]

Hello,

I'm asking this here b/c it's about putting down the copper plumbing in a bathroom, and the timber joists of my floor.

Is there a rule of thumb around how one is supposed to lay down the pipes? Do you just cut out a notch of the joist at the top, or are you supposed to go through the joist (making a hole in the centre and inserting the pipes through?

My joists are about 15cm thick, and I have seen that my builder/plumber has taken out 4 to 5 cm from the top in places, to lay either 1.5cm pipe or 2.2cm pipe. Does this make any sense? I am going to find out who is doing the notches, whether it is the builder's guys, or the plumber himself. I'm referring to my bathroom here. The rest of the flat has wider timber joists, and I think they kept the level of the pipes the same, so when they came into the bathroom, they just started cutting notches across each joist.

Any feedback would be appreciated. I would have thought the proper approach was to make a hole through the joist.

Thanks.

 

[Weedrip]

I believe its an 1/8 the depth [generally] however there are permitted zones along the joist. if you try a google search for depth of joist notching you will find many illustrations that will help to clarify the permitted notching. Basically its 19mm in a six inch joist so they are being a bit 'yeehaa' really at 40 /50mm depth if I have understood you.

however in 38 years of plumbing and seeing many forms of bodging in my time I have never seen a floor joist break, except once and that was a timber fault.

But them is the rules and ultimately there for some useful purpose.