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!!

 

[telectrix]

i would not evenj consider buying a house with pathetic twig joists, those flimsy roof trusses and weetabix floors.

 

[Engineer54]

i would not evenj consider buying a house with pathetic twig joists, those flimsy roof trusses and weetabix floors.

But there are still some out there, that would have you believe they are better and safer houses, than those of the past!! lol!!!

 

[Silly Sausage]

i would not evenj consider buying a house with pathetic twig joists, those flimsy roof trusses and weetabix floors.

:iagree:

And they're so small with ridiculously low ceilings. Cheap just to slap up 2.4m plasterboard I suppose.

 

[telectrix]

i'll let you know in 50 years time. LOL. as if i'll live that long. be in guiness book of records.

 

[Chr!s]

Try This.
http://niceic.com/Uploads/File3777.pdf

 

[telectrix]

wonder if there's a similar guide for wet-heads. it would have to be in simple pictures, though.

 

[drew35]

You should see the joists at a barn conversion I've been working at. The "plumbers" have drilled holes in each ceiling joist to route the underfloor heating pipes through, the holes must be 40mm, and the joists are only 150mm. But its the fact that the holes are everywhere, some on the centre line, some well below, some well above. In some joists there are two holes one vertically, well they offset them slightly, but that's 80mm out of 150mm!!!

And that's after I drilled two 25mm holes in each joist between 0.25 and 0.4 of span.

With under floor heating pipes why don't they just batten the top of the joists? Then all they have to do is notch a small piece out to get past the joist, and the pipe stays near the floor?

It does make me wonder why we all bother so much when no other trade seems to give a monkeys!

 

[wildgoose]

Love central holes but hate notches!!

At a house in the week found 2 live nails because some DIY knob thought they would stop creaking by nailing the centre of the floorboard. Nails missed the pipes but the bodged-in cable run sandwiched inbetween the pipes, got holed twice (L on one & across N/E on the other). System protected by an inoperative 'Voltage Operated Earth Leakage Breaker'.

Good job it nail didn't go through the pipes - that would have been serious!!!!!!!!!!!!!!!