Need to drill a hole in joist near to wall - is this OK?

[croz1977]

Hi,

I am fitting a new radiator and need to drill two small holes in the floor joists for 15mm pipe. However I was planning on drilling these in parallel about 30 cm from the wall, which I now read is probably against building regs - any ideas apart form re-routing the plumbing?

Croz

 

[ironman1]

Go ahead & drill it.

 

[ChrisR]

The building regs are online - I'll let you search.
Probably you'd be breaking the rules, but very few plumbers pay them any attention, and very few houses fall down as a result.
The proper answer is to bore holes through, or notch, the joists where the BRs DO permit.

 

[seco services]

drilling is

0.25 x length of joist in meters =
0.40 x length of joist in meters =
gives you your safe area to drill from each end of the joist.

0.25 x depth of joist =
gives you max size hole.

 

[ajrobb]

Within the permitted zone (25% to 40% of span) for holes, they must be drilled through the middle of the joist (the neutral axis) as the top and bottom are considerably stressed. The permitted 12.5mm notch in the first 33% of the span is in the region of shear rather than bending.

I don't see that drilling 2 x 16mm holes through the middle of the joist with centres spaced at least 64mm is going to remove much more material than a notch. They will magnify the shear stress which is pulling the grain apart. Perhaps a vertical strap between the holes would help stop the grain splitting.

 

[Nige F]

in the Real World it depends on the span of the joist - If it`s spanning a 6 foot bathroom and you take a notch out close to the outside wall - it won`t fall down in 20 years - well it didn`t @ my first house