Gas pipes notched through bottom of ceiling joists

[JohnD]

I have a problem

no you don't.

you can have the pipes fixed to the wall.

Safe, easy, cheap.

No problem.

 

[Lower]

Hi Muggles
Tracpipe looks like a good option however I'm meeting some resistance from the perspective of "that's what we always do" & "there's nothing wrong with it". To move it on I've said if he can get sign off from a Gas Safe engineer to the effect of what he's proposing is OK then I'll go with it. Any thoughts?

i appreciate you need to keep your builder on side.

However, you are the customer and its your house. If you're not comfortable with it, tell them that you don't him to notch the bottom of your joists and that he needs to find another way. Its not really a gas safe engineer's judgment to make so that's not really a solution.

Just get the pipes run around the perimeter of the room.

 

[Tobbs]

Well thanks for all the replies. I obviously didn't explain myself well & I've got some of you at cross purposes. Whilst notches in the bottom of the joists wouldn't comply with the letter of the NHBC standard, from the structural perspective I'm not concerned because I'm a chartered civil & structural engineer. Have been for forty years. If it wasn't structurally sound there'd be no chance of this happening. My only concern is on the gas safety side of things of which I know very little - hence reference to Gas Safe sign off. There doesn't seem to be any guidance in the gas regulations on the clearance distance of gas pipes hidden behind walls/ceilings/box outs etc. What would stop someone running a hidden gas pipe right up behind the plasterboard of a stud wall for example? Or chased into a brick wall? Even if it were in a specific box out or hidden behind coving without it being marked 'gas pipe' or similar there's no guarantee someone wouldn't unknowingly drill or nail into it. Whilst it might not be good practice if I can't point to a regulation or industry guidance on the subject my builder can reasonably claim what he always does is fine from the gas safety perspective & charge me extra for doing something else.
Thoughts?

 

[muggles]

Ah, well if you are a structural engineer and you're happy with the proposal then that's all good. Personally I'd still prefer the Tracpipe option, but it's your house As for the other gas pipe locations you mention, it's perfectly acceptable to run a gas pipe behind a stud wall. It needs to be encased in plaster so that a leak can't fill the void between plasterboard and wall, and it can only run vertically. Gas pipes in voids sometimes need ventilation to prevent a dangerous build-up in the event of a leak, and where it's notched in it's good practise to have anti-drill plates crossing the notches.

 

[denso13]

Whilst notches in the bottom of the joists wouldn't comply with the letter of the NHBC standard

What have the NHBC got to do with your property?

 

[Tobbs]

What have the NHBC got to do with your property?

Section 6.4.18 of the NHBC Standards document covers notching & drilling timber joists. It gives limits on sizes depths & locations of notches with the caveat that "Notching and drilling should be designed by an engineer where... ...it does not meet the guidelines in this chapter". It's one of several similar UK building design & construction documents (local & national) that all point back to the various TRADA (The Timber Research and Development Association) publications which instruct on the implementation of Eurocode 5 - 'Design of timber structures'. NHBC et al give very simple, conservative, worst case, one size fits all guidance (e.g. safe span tables) but if all else fails you can use Eurocode 5 & work everything out from first principles...

 

[denso13]

Section 6.4.18 of the NHBC Standards document.....

Yes, I know all that, just strange you quoted NHBC regs for an old property.

 

[Tobbs]

Yes, I know all that, just strange you quoted NHBC regs for an old property.

What design & construction standards would you suggest should be applied to contemporary building work on houses of this vintage?

 

[denso13]

What design & construction standards would you suggest should be applied to contemporary building work on houses of this vintage?

The Building Regulations. You might say NHBC are mostly the same but I just found the reference to NHBC, who are involved with new build warranties, strange. Nothing more than that.