Holes in Joist

dave82_2

Hi,

Our house is being rewired and the sparks aprentice has drilled the holes to high on the joist so they had to dril some more

it now looks a bit like this ( not to any scale)

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( ....)....... ...........( ( ....).......


...............(.... )

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They have told me it is fine however being catious I might put some sort of reinforcement over the top two holes which were drilled in error. I will messure the distances etc and compare to building regs.

Anyway my question is what do I need to do to strengthen the joist is there some sort of steal strapping availiable.

Is this all overkill?

Cheers

keith969

dave82 wrote: »

Is this all overkill?

Probably. And if there is a problem subsequently, it will be harder making a claim against them if you've modified their work.

wallbash

As the holes are staggered .... I would not be too worried.

We should ask , how big are the holes / size of joists

Yooj_2

Firstly, are they ceiling joists or floor joists, and what size are they?
If ceiling joists, is your roof of a truss type? If so, then it should not have been drilled.

If floor joist, then consult Building Regs for permissible notches/hole sizes based upon joist size.

Yooj

dave82_2

Hi these are floor joists. I haven't been in the loft yet to see what they have done up there!!! I will take mesurements as I know it is hard to say if this will be a problem without them.

Cheers

dave82_2

For arguments sake if these do breach building regs is there any product avialiable to strengthen the weakened areas or am I looking at new joists!!!!

Yooj_2

dave82 wrote: »

Hi these are floor joists. I haven't been in the loft yet to see what they have done up there!!! I will take mesurements as I know it is hard to say if this will be a problem without them.

Cheers

Probably nothing to worry about in terms of the floor joists...If I remember correctly, the holes should be no more that a quarter of the depth of the joist, i.e. if joist is 100mm, then maximum hole size is 25mm...if the three holes are smaller than this, then they should be fine.

For covering bases sake should anything happen post event, then get the electrical contractor to provide you with a written testament that in his professional opinion, the erroneous holes do not pose a problem structurally. Furthermore, I am assuming that he has PL insurance, and is a member of a suitable scheme, i.e. NAPIT, ELECSA, NICEIC etc...and if so, then his work should be backed by a 5/6 year insurance backed guarantee for workmanship.

Go and have a look in the loft, as this could be a different kettle of fish altogether if they have drilled there.

Yooj

Yooj_2

dave82 wrote: »

For arguments sake if these do breach building regs is there any product avialiable to strengthen the weakened areas or am I looking at new joists!!!!

As before..it is unlikely to have seriously weakened the structure...though get the contractor to put that in writing...if he is unwilling, then tell him to get a structural engineers report to say all is well.

In terms of strengthening, unlikely...In cases where I have seen holes drilled in the wrong places in floor joists, I have seen the building inspector insist on the holes being plugged...More to stop anyone using them, rather that actually strengthening the joist.

Yooj

ormus

as above. more a case of stopping anyone using them.
you will probably be ok. if paranoid then plug the holes with wooden plugs glued in. and cover with metal straps or plywood side pieces.
either side and bolted through.

andrew-b

Test it by threading a rope through the joist and hanging the apprentice from it?!

dave82_2

Cheers,

The company is fully certified and registered so I will just plu them up and get them to sign it off.

I was just worried because they did it on every joist the depth of the house!!

D