prexisting hole in garage joist

[ianphilip007]

hi there

i am rewiring and removing old electrical wiring to detached garage and need some claification on two existing holes going through 6x2 garage flat roof joists. Both holes do not comply with the building regulations re span (0.25-0.40). As they are already there would i be contravening the regulations if i decided to use them as they are. my main issue is this is probably one of the jobs i am going to be assessed on so wouldnt want to fail due to existing holes being outside regulations.

problem is one of the holes is very close to where i may need to drill the joist, Joist span is 2.7m and hole is drilled 1.3 from support. (2.7x0.4 =1.08) in my view drilling another hole to meet the span requirements would surly just weaken the joist

 

[malcolmsanford]

After you finish the wiring is the joist then going to be covered up, if so I doubt in a million years the assessor will say now lad when you run the cables in, did you adhere to Part A of the building regulations, expose the joist so I can see them" ................ If you really worried then put a steel protection plate across the top where the hole is .............

To me your going to weaken the joist more by trying to adhere to regulations, and drilling more holes in it to conform. Re-use them and don't worry

 

[ianphilip007]

thanks malcom my concern is that the roof joists in the garage flatroof are all exsposed so they will be clearly visable to the assessor. im sure the one i may use is close enough anyway well 22mm out

 

[malcolmsanford]

Well Ian if he did mention anything, I would be saying that you used existing holes, and if you didn't and drilled new ones in your opinion it would be weakening the joist further, I like to see him argue what he would have done instead.

I always found that if you honest, and straight, and tell him yes you know they are not exactly in the right place, it proves you do know the regs. I wouldn't worry too much to be honest

 

[brman]

thanks malcom my concern is that the roof joists in the garage flatroof are all exsposed so they will be clearly visable to the assessor. im sure the one i may use is close enough anyway well 22mm out

I'd talk to the scheme and get their advise. Which will almost certainly be the same as Malcolm's but you are then covered.

 

[ianphilip007]

the other has been drilled about 10mm fron the garage wall into the joist, (was used for the preexisting conduit supply) so way outside the span requirements.

 

[ianphilip007]

thanks guys i thought as much, just worrying too much, but just dont want to be tripped up by using a hole that i know doesnt comply. But again malcom is right