Notch in underside of joist

[mquinton1980]

Hi all

I am currently preparing my garage in advance of having a garage conversion carried out. I have striped the ceiling of plasterboard ready for downlighters to be installed and a new hot water supply from the airing cupboard above.

I left the plumber to connect up to to a hot water pipe in the airing cupboard which he did with no problem but when I looked he has removed a 22mm notch (more liked hacked away) in the underside of one of the joists to take the pipework above the ceiling level. I have 8inch joists and know that a notch this size is fine in the top but what about underneath? I've also checked that is in the first third of the joist which is ok.

What should I do? Will the building inspector find it a massive problem? The notch looks small in comparison to the depth of the joist and its the last joist before the outside wall so little weight above. Any ideas? Or will it be ok?

Thanks

Mark[/quote]

 

[PrenticeBoyofDerry]

Building Controls Guidance Note 7
States
"Notches may only be made in the top of the joists, within the permitted area."

 

[mquinton1980]

So where do I go from here?

I don't think it's big enough to be a big structural problem, should I tell the building inspector when he comes around to look at the place or just leave him to it?

I guess one answer is to re-route the pipe through the middle of the joist and strap the existing notch with plywood and coach bolts. Would you agree?

Thanks

Mark

 

[PrenticeBoyofDerry]

Your plumber should have known better.
Your BCO/inspector may turn a blind eye, if the structural calcs have been over engineered.
I could be worth a call to them, you don't need to tell them who you are and say what if...........?
But I would re-route the pipe and strap up the joist, belt and braces. (but that's me)

 

[big-all]

what is the actual joist sizes span and centres[spacings between]you must never notch underneath but if the joists are on the chunky side you may be ok assuming the grain at the notch is parralell and not at all diagonal

 

[mquinton1980]

Well it's an 8 inch joist spanning 2450mm. It's the last joist before the outside wall and it's been hacked to a depth of 22mm 760mm from one end which is a block wall with joist hangers. Sorry don't know the joist centres but I can find out.

Is it possible to strengthen the joist without putting anything beneath the member as that's where my new plasterboard ceiling will be?

Thank you guys

Mark

 

[mquinton1980]

Just been in the garage to measure.... there is another joist running adjacent to the joist in questions - only 185mm away, probably because this runs under the bathroom above (under bath). In the other direction the outside wall is only 80mm away.

 

[big-all]

if you take the maximum spacings it comes out at 13'6" for 8x2"
so if we take the average i recon you should be fine especialy if the flooring terminates on the wall[supported by]
http://www.awc.org/calculators/span...bmit=Calculate+Maximum+Horizontal+Span#answer

 

[markquinton1980]

Thank you very much for your help. the span only covers a bathroom and the other end it's a steel beam. FIngers crossed it will be mine especially as it's only a short centre to the next beam. now just got to stop the sparky from making the same mistakes when he does the downlighters. wonder how many notches are joists that are present that homeowners would never be aware of.

Thanks again.

 

[Static]

Joist should be fine for span and load even with removed notch.. for that kind of span the joists are alot larger than required..

 

[PrenticeBoyofDerry]

now just got to stop the sparky from making the same mistakes when he does the downlighters.

Hopefully they will follow the permitted routes
//www.diynot.com/wiki/electrics:installation_techniques:route

wonder how many notches are joists that are present that homeowners would never be aware of.

Come across them all the time, not so much in the newer developments, but plenty of evidence of DIYers not following, regs and requirements.
Lofts are usually the worst area, as it is common place to have them boarded out. So the cables are already in place and the easyest method is to notch the top of the joists out, rather than re-route by holing joists, using 50mm rule.
Not to this day have I seen a loft that has been boarded out by a diyer, have mechanical protection over the cables and some so called pros are also ignorant to the regulations.

 

[^woody^]

Don't worry about a notch on a single joist

Untitled

• ^woody^
• 16 Jun 2008
• 7

If need be you can fix some ply either side of the joist to strengthen it