Holes in Joist

Yooj_2

1984ReturnsForReal wrote: »

http://www.diynot.com/forums/viewtopic.php?p=353927#353927


In other words the holes should be at least 1/4 of the way down/up & at least 3 hole widths apart.

Your interpretation is not quite right...The 0.25 and 0.4 figures are pertaining to the horizontal position of the hole, i.e. if (for arguments sake) the joist had a span of 10 metres, then a hole could be drilled between the 2.5 metre and 4 metre point from the edge of the joist, assuming the joist were only supported at either end.

In terms of vertical positioning of a hole to be drilled...this should always be in the vertical centre point. equidistant from the top and bottom of joist.

Notches have different parameters to holes.

Yooj

1984ReturnsForReal_2

Yooj wrote: »

Your interpretation is not quite right...The 0.25 and 0.4 figures are pertaining to the horizontal position of the hole, i.e. if (for arguments sake) the joist had a span of 10 metres, then a hole could be drilled between the 2.5 metre and 4 metre point from the edge of the joist, assuming the joist were only supported at either end.

In terms of vertical positioning of a hole to be drilled...this should always be in the vertical centre point. equidistant from the top and bottom of joist.

Notches have different parameters to holes.

Yooj

http://books.google.co.uk/books?id=qLekBAZUJloC&pg=PA181&lpg=PA181&dq=BS7671+joist+hole+522-06-05&source=bl&ots=nKdcdwe4OO&sig=KTozMfIytN3bc7Q4yyRRdio0W8I&hl=en&ei=Gig3TMfTFoL80wTUpfDoAw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCoQ6AEwBQ#v=onepage&q&f=false


Figure 182.

booty40uk

http://books.google.co.uk/books?id=q...page&q&f=false

The "16th edition" bit is a bit of a giveaway

1984ReturnsForReal_2

Yeah.

Its a bit of a giveaway that so many "electricians" have posted on here not knowing the building regs & recomendations..

NHBC - http://www.nhbc.co.uk/NHBCPublicatio...d,21418,en.pdf you want page 13.

http://www.nhbc.co.uk/NHBCPublications/LiteratureLibrary/Technical/StandardsExtra/filedownload,9930,en.pdf pg 5


Electrics has nothing to do with it. It is the same for pipes or anything else you cut/drill out holes for in joists. Or do you think that because the earth bonding has changed & RDCs are fitted that will stop a roof collapsing?

bordercars

buy a broom stick the size of the holes cut into lengths and plug up.. dont bother with glue just go for a tight fit.

BillTrac

oh for the good old days when I was an apprentice where you cut notches out of joists....:rotfl:

I remember one site I was working on and as there was no power at that time, not even temporary power, all holes had to be drilled using a bit and auger!!!!! We apprentices were given the lovely job of drilling all the holes required.

All went well until the foreman realised that one of the others had drilled lovely, neat, perfectly in line 1" holes(pre-metric..see said the old days) through the joist of the one room in the whole building that were to be left on display. I certainly learnt some new words that day...:T

Yooj_2

1984ReturnsForReal wrote: »

....


Electrics has nothing to do with it. It is the same for pipes or anything else you cut/drill out holes for in joists...

Absolutely...This is purely a structural issue, and contained within the Building Regulations rather than the Wiring Regulations, though these elements tend to be reflected within various guidance notes and publications for electrical contractors to refer to.

BTW, the NHBC links provided by 1984ReturnsForReal provide an excellent worked example of the interpretation of the regulations for this issue.

Yooj