1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Recessed gas box and cavity tray, dpm

Discussion in 'Building' started by xdrive, 13 Nov 2020.

  1. xdrive

    xdrive

    Joined:
    2 Mar 2019
    Messages:
    250
    Thanks Received:
    1
    Country:
    United Kingdom
    Hi.

    I've made an opening for gas meter.

    I've installed lintel.

    Do I need cavity tray or damp proofing?

    Will be in extension that's currently being built from blocks and finish will be K render.

    Also I would like to go for black hockey stick that goes inside cavity. I know it needs to be below 450mm to ground level. That is foundation blocks. Do I break the block so I can put the black hockey stick in or would I be better off with white external stick.

    Cheers
     
  2. xdrive

    xdrive

    Joined:
    2 Mar 2019
    Messages:
    250
    Thanks Received:
    1
    Country:
    United Kingdom
    Anyone please?
     
  3. Sponsored Links
  4. ^woody^

    ^woody^

    Joined:
    3 Sep 2006
    Messages:
    32,331
    Thanks Received:
    4,377
    Location:
    West Mids
    Country:
    United Kingdom
    A cavity tray should be fitted. Also a polythene sheet behind it and wider than it - 700mm or so.

    Hockey stick needs to be surface mounted, as no holes are permitted in the box that could allow gas to leak into the cavity.

    Have you got a guide from National Grid? There are other criteria including height.
     
    • Thanks Thanks x 1
  5. xdrive

    xdrive

    Joined:
    2 Mar 2019
    Messages:
    250
    Thanks Received:
    1
    Country:
    United Kingdom
    Hi. Yes I'm aware of height to be between 500mm and 1000mm from ground level.

    Problem is I have put the inner leaf blocks up so can the tray be fitted or am I better off grinding inch of mortar and inserting dpm as tray.

    I have dpm 1000ga which is 250micro units (0.25mm) so that should be fine for back of box.

    I'm also thinking I won't have any weep holes as external will be K rendered and the spigot that goes into inner leaf from meter box would mean a hole in polythene sheet so it won't stop much damp.

    Are these really necessary?

    It also mentions cavity tray OR polythene sheet. So only one would be necessary?

    Cheers
     
    Last edited: 14 Nov 2020
  6. Sponsored Links
  7. ^woody^

    ^woody^

    Joined:
    3 Sep 2006
    Messages:
    32,331
    Thanks Received:
    4,377
    Location:
    West Mids
    Country:
    United Kingdom
    I don't know if the polythene sheet is anything to do with gas regs, or if they are just making it up in some attempt to stop damp. I can't see a point in it.

    Whether you cut a tray in, stick it with silicone or rely on the lintel is a site decision.
     
    • Like Like x 1
Loading...

Share This Page