Advice on attaching electrical boxes

Discussion in 'Other Trades Talk' started by Matrad, Mar 11, 2018.

  1. Matrad

    Matrad New Member

    Hi all

    Any advice on how to effectively attach ectrical boxes to brick & Block walls that have been very badly chased i.e. A very uneven back with up to 3cm to fill in some parts to get them to finish slightly proud of the wall ready for plastering?
  2. chippie244

    chippie244 Well-Known Member

    Expanding foam?
    WillyEckerslike and KIAB like this.
  3. dobbie

    dobbie Well-Known Member

    You will need to flatten the brick or block using a comb chisel,chisel or and bolster,whichever is your choice.
    When you have the bricks/blocks flat fit deeper boxes or fit extension collars to the boxes to bring out to plaster finish.
  4. dobbie

    dobbie Well-Known Member

    Where is your horse stabled.
  5. Matrad

    Matrad New Member

    Is there a specific type of foam for this, in addition would this be a sound enough fix.
  6. chippie244

    chippie244 Well-Known Member

    I'll await other opinions.
  7. dobbie

    dobbie Well-Known Member

    That is a cowboy bodge job.Do it properly.
  8. Chuck a wodge of sand/cement mix in there, scrape it to required depth, Bob's ur uncle etc.
  9. KIAB

    KIAB Well-Known Member

    Last edited: Mar 11, 2018
  10. dobbie

    dobbie Well-Known Member

    Certain foams used to damage the pvc on cables,read regulation 522.5.3.

    Kiab I have, unlike you, worked in the building and construction industry on sites,both industrial, commercial and domestic over the years.
    Every thing I know is through actual experience and not browsing diy forums.

    From what I gather you once maybe worked in a builders merchants.
    I will not be the only one on here who laughs at the porkies you come out with,maybe some of the stories are true you heard when behind the counter.
  11. KIAB

    KIAB Well-Known Member

    I've worked both side of the counter, mainly domestic nearly 40 years, make it 35 years, if I allow for accidents,etc.
    Last edited: Mar 11, 2018
  12. Sparkielev

    Sparkielev Well-Known Member

    I have used foam when I have encountered hollow brick walls were you can't get a fixing or fast dry cement, in this case tho just level off brick fit a deeper box
  13. DIYDave.

    DIYDave. Well-Known Member

    My favourite ..... gotta be bonding plaster;

    Almost no depth limitation


    Sets even quicker if outta date

    Dampen brick or PVA 5-1 water

    Chuck in bonding

    Tap in back box to required level

    Drill and plug through bonding into brick

    Semi tighten screws, fully tighten once bonding set

    I’m only diy me but I’ve used this method few times and it’s a lovely job :)
  14. chippie244

    chippie244 Well-Known Member

    So pretty much like using expanding foam. :)
  15. metrokitchens

    metrokitchens Active Member

    Bonding plaster all the way. Fill the hole and set the back box in. Push in a couple of red plugs and screw when dry.
    Jobs a good un. Tea and biscuits time.
  16. DIYDave.

    DIYDave. Well-Known Member

    Thing is with me as diy, whenever I’ve bought a can of foam, I only need a squirt of it, never the full can

    Have a can of the Everbuild foam cleaner and it’s really excellent stuff. Cleans the spray tube in seconds and cleans the nozzle on the can

    Can goes back into garage for some months, next time you need to use it, can never works, even though I’ve cleaned it out so waste 80% of the can

    Not worth me buying gun and gun grade foam, just don’t use enough

    So for me, I decant a sack of bonding into two 10ltr paint buckets and it lasts me for an age

    As mentioned, when out of date, it sets quicker which can be handy and if using for a small repair, is fine as you may only have 5-10 mins workable time

    So no, nothing like foam really chips :)
  17. DIYDave.

    DIYDave. Well-Known Member

    Cheers metro, my thoughts exactly :)
  18. chippie244

    chippie244 Well-Known Member

    I meant the technique, I use lots of foam but never use bonding so don't have any of that around.
  19. Matrad

    Matrad New Member

    Thanks for your response
  20. Matrad

    Matrad New Member

    Thanks for your response.

    Do I need to make the bonding mix thicker than normal & will the box need to by held in place while it goes off?

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