Thorfun

i don't get this....tile backer board (not Hardie backer board) is cuttable with a Stanley knife (other manufacturers are available). it couldn't be easier and is in no way any harder than plasterboard to cut.

if it's being tiles maybe use tile back board (the XPS stuff like Jackoboard or Marmox board etc rather than Hardie!). be aware though that if using 12mm tile backer board for the Jackoboard i used the manufacturer said 300mm centers so i had to noggin a lot to obtain that. i think 20mm Jackoboard is fine with 600mm centers.

my sparky didn't say anything against it. i'd say just put them near the top of the unit so if there's a leak they won't be submerged! plus i'm sure you're using nice new RCBOs which make everything super safe anyway. 😉

i never ignore what you say, sometimes i just choose not to follow it. there is a big difference. 😉

i'm finishing the last bit of 1st fix plumbing this weekend and need to run the kitchen sink waste to the soil pipe. that is a run of about 5m and will be attached to the basement ceiling. the waste pipe is 40mm from the sink through the floor to the basement ceiling where i will convert to 50mm pipe. is a 5m run in 50mm pipe ok? i've read somewhere about upsizing for long runs of waste pipe but am not sure what counts as a long run and what is an upsizing. do i need to go from 50mm to 110mm at some point before the soil pipe i'm joining?

it's all done with the angle grinder! i am very impressed. he is a very good tiler though so i shouldn't be surprised.

i'll pop out and ask him.....

sorry for the delay. here's what my tiler did for ours.

I honestly can’t remember at the moment. I see that they’re also used for the occupancy sensors so need to look into whether I need them for that. I’ll get back to you and thank you!

Wish I’d seen this before as I tried to hack out the OSB behind the plasterboard to get the lugs to fit. 🤦‍♂️

thank you so much for this! i will now definitely stick with Appleby and figure out the best way to reduce the thickness of the plasterboard/skim make up.

our tiler is doing our bathrooms at the moment. i'll take a photo of how they've been done when i get home and will post it up here later.

i'm actually happy with the thick two coats. at least i know it's solid! i love the silver lining of having clean back boxes. i'll focus on that. 😆

pretty standard for a self-builder, no? 😉

i haven't bought all the back boxes yet. so i'm tempted to try those Knightsbridge ones @Mr Punter linked at TLC to see if they work and what sort of quality they are.

i wonder how removing cutouts from the back will effect the strength of the PB? without the paper there will it make it a bit brittle in that area where the lug is holding the back box in place?

nope. this particular wall is 140mm deep so nothing behind. ok, will give that a try as well just 2 to get ready for the AC install tomorrow! many many more to go. 😉 way too late for that. i did ask the plasterers and they, obviously, said they'd prefer to not cut out before they skim. and as they did the boarding i wouldn't have had time anyway.

Thanks. Although when you have over 100 to fit that starts to seem like a daunting task! 😂

thank you! any idea of the quality? when reading threads about plasterboard back boxes @ProDave mentioned that some are a lot poorer than others and he only uses Appleby as they're good quality.

does snipping the lugs off not reduce the effectiveness of the box being held in place? also, according to the Q&A here https://www.screwfix.com/p/appleby-1-gang-dry-lining-knockout-box-47mm/83270 the 47mm boxes are also meant for 6.3mm - 15mm thicknesses

might be tricky to sand back just around the back box though! might be easier to cut a bit off the back of the plasterboard! I thought a skim was 3mm with the 2 coats of plaster. at least that's what I worked all our measurements to. which makes me wonder why the back boxes aren't made for 16mm thicknesses. unless these days they don't expect anyone to skim the walls and just tape and fill. or maybe I need to find another brand of back box that will do slightly thicker wall makeups?

greetings. I've started to cut out and fit back boxes but I'm finding that our makeup of 12.5mm plasterboard and skim is about 16mm. I'm using the Appleby back boxes as recommended by @ProDave but I don't get the satisfactory 'click' when the clips fit in place. is that a problem? the back boxes are apparently designed and tested specifically for dry wall/plasterboard, with a thickness of 6.35-15mm. so I'm about 1mm too thick. is there a way to make it fit so they click in to place? or am I being special and worrying about nothing as usual?

thanks guys. happy to use the round ones especially as I have cut holes/squares for them yet and the price direct from Loxone is decent. and I already have a 68mm hole saw! 😉 I need to put an order in for the terminal blocks so I'll get a big order together to save on delivery costs.

glad I didn't start cutting out squares in the plasterboard yet then!

evening all. happy Sunday to you. I'm looking at buying all our electrical back boxes soon and I think I remember reading somewhere that the Loxone Touch Tree switches need a circular back box. is that correct? is it these https://shop.loxone.com/enuk/circular-dry-lining-box.html?