Gas Meter Box DPM

[shaky1105]

Hi. Hope I've posted this in the right forum as I've already asked questions re: the meter box dimensions/positioning in the Plumbing forum but thought seeing as this is related to the actual fitting of the box this board would be best.

I am having my gas meter refitted from a surface mounted box into a recessed box by NGN. My builder is going to fit the box for me but has never actually fitted one where the gas pipe will exit the rear of the box through the spigot. All the ones he's fitted (including a supplementary electricity box he did for me) have had the cables/pipework exiting the box either from the side or below, through the architrave of the box, so all he's done is to trap the sheet between the box and the outer leaf, turn it upwards into the cavity and run it down the inner leaf where he traps it again between the box and outer leaf.

Will it be acceptable to cut a hole through the dpm sheet he's going to fit on the inner leaf to allow the spigot to get into the building ?

He seems to think this would be the only really practicable way of doing it and still allow the dpm sheet to perform reasonably as required but said he would be quite happy for me to check for myself.

TIA

 

[noseall]

Why is a DPM being fitted to an inner leaf?

 

[shaky1105]

Why is a DPM being fitted to an inner leaf?

As is always the case, I can't find the image online that I saw but it was basically like the one I have attached. If I'm looking at this correctly, if any damp forms on the outer leaf, the dpm in red should stop it from bridging the cavity and getting onto the inner leaf ?

The image I was trying to find was from an official site somewhere and says the sheet should be a minimum of 700mm wide, so I presume it's correct. I just want to make sure that if a hole is cut in that sheet to allow the spigot to get into the building, that will be OK and doesn't need any other work doing.

TIA

 

[noseall]

That DPM aint doing jack. Any water will perform the same with or without that DPM. Besides, DPM does not shape like it is showing in the drawing. Maybe if you were building from scratch, then a CT above would have been useful but otherwise I can't see the benefit of what is being shown in the image.

 

[^woody^]

You need a lintel and cavity tray above the box, not a dpm behind it.

 

[shaky1105]

Thanks for the replies, I've attached an image that is actually inside the new box. The only reason I am asking is that somewhere on here, I remember seeing someone complaining about damp appearing on their inside wall just behind the meter box so I just wanted to make sure whatever is best for avoiding that is carried out. To be fair, my builder is good with anything like this and will try to do what I ask but I don't want him to be doing work that isn't really needed as he will prolly think I'm an idiot - lol.

I think he did mention a cavity tray would be a possibility but I also seem to remember him saying that a lintel wouldn't be needed as the box position means it will only span two full bricks.

I think I'll leave it up to him as he's always been honest with me. I was just concerned about the possibility of damp affecting the internals.

Thanks again.

 

[^woody^]

The drawing is crap. What's the arrow pointing to?

Anyway the box is made of plastic, same as a polythene sheet.

"Only two bricks" don't matter, but a lintel should be installed, as should a cavity tray above - not below, at the sides or behind, above.

 

[shaky1105]

OK, so cavity tray it is then - cheers. I was just concerned re the damp issue but obviously there's no worries about that judging by your replies. I must admit, I can't see why a lintel is needed as there's only three bricks in the triangle above the box opening but if you guys see a need for it, I'll suggest it to the builder.

 

[Scot22]

Rather rude woody . Didn't you notice both arrows have labels ?

 

[^woody^]

Rather rude woody . Didn't you notice both arrows have labels ?

"Polythene Sheet 0.1mm thick, or a suitable cavity tray, shall be fitted by the builder" and an arrow pointing to some unknown thing hanging off the bottom of the box!

Is that where the cavity tray goes? And the polythene? What is that thing anyway?

 

[Scot22]

To describe me as clueless about DIY and building would be exaggerating my ability. I totally respect your superiority.
However, maybe it is pompous, I am concerned by how people now feel free to speak to people in courteous language. The O P may well not be bothered but I feel we need a more polite society.

 

[^woody^]

I am concerned by how people now feel free to speak to people in courteous language

WTF?

Where is the discourtesy in the posts above?

But I will ask Mr Chumley-Warner and Mr Greystone, who are the fellows to whom we have entrusted manual terrain exhuming, entrenchment formation plus concrete amalgamation and placement services on our construction project.

 

[Scot22]

Good stuff. I trust they do a decent job.

if you do not appreciate why referring to something as crap is discouraged then no point in any further comment from me.

 

[^woody^]

Good stuff. I trust they do a decent job.

if you do not appreciate why referring to something as crap is discouraged then no point in any further comment from me.

That's crap.

Toodle-pip

 

[Scot22]

Jolly dee. So revoir.