Piping through joists

[diversion]

Hi, I have to move a radiator which involves lifting one floorboard the length of the room and passing two 15mm pipes across/through about 20 joists!
Is this a problem? Am I OK to cut a 15mm deep slot in the top of each joist and rest the pipes in the slot?
I will lag the pipes slightly to prevent creaking, my main concern is the load bearing capacity of joists with a slot in them!!
I'd welcome any ideas on this. Thanks a lot - Chris

 

[Bahco]

Am I OK to cut a 15mm deep slot in the top of each joist and rest the pipes in the slot?

Cut a 20 mm deep notch in the joists. You are allowed to notch up to 1/8 of joist depth (assuming yours are 8x2 joists)

Do lag to avoid expansion noises.

 

[namsag]

If your joists are less than 100mm deep do not notch at all

 

[TicklyT]

Don't forget that notches are only permitted in certain parts of a joist - Between 0.07 and 0.25 span, IIRC

Similarly, holes through joists are permitted on the centre line in the area 0.25 - 0.4 span, and should be no closer than three diameters apart.

 

[gas4you]

and should be no closer than three diameters apart.

Or 100mm minimum

 

[diversion]

Thanks all of you, that's a great help. Chris