Joists

[Ross1]

I am familiar with the regs on a new build 25% and 40% of the joist span is for your cable holes (hope im right there) In an extension though do the same rules apply cause I'm in a situation where I need to drill within the first 10% of the span for a shower cable.Cheers

 

[rich.250]

Aslong as it doesn't effect the load baring of the joist I dont see an issue.
A small hole through the centre of the joist should be fine.

 

[sparkshower]

isnt the rule for drilling any joist 0.125 * the height of the joist, think its in the electricians guide to the building regs and also the on site guide, this gives the maximum sized hole to drill

 

[morph]

the buildings regs are clear that on all buildings "part A" should be applied as it is statutory
holes are 0.25 to 0.40
notches are 0.07 to 0.25
nothing in the middler

 

[robskiing]

How come then a plumber will come along after you have got boards up and whack great big notches above where you have carefully drilled your holes central in the joist happened quite a few times to me lately they don't give a flying f..... to the building regs

 

[morph]

How come then a plumber will come along after you have got boards up and whack great big notches above where you have carefully drilled your holes central in the joist happened quite a few times to me lately they don't give a flying f..... to the building regs

they should nt but of course they do

 

[i=p/u]

just look after yourselves

 

[SPARTYKUS]

THATS why I love old miners cottages (for example!) - no mucking about in them days with joists, just chuck a tree in. Drill away it'll support a skyscraper

 

[pjcomp]

How come then a plumber will come along after you have got boards up and whack great big notches above where you have carefully drilled your holes central in the joist happened quite a few times to me lately they don't give a flying f..... to the building regs

Because their pipes go in the notches, hold up the floorboards, and have more than enough strength to maintain the building's integrity

pj

 

[Engineer54]

I think drilling any holes or chopping of slots in the twig like joists they use today in house building, will seriously affect them. Unlike the sizes of joists used in yester-years, when it was rare to see less than 6 X 2'' joists, many being twice that width!!