Cutting in 140mm shower rough in box - any advice?

[AlexJones]

Hi Guys

Needed some advice on cutting in my Grohe Raipdo rough in smart box which essentially is the back box for the front end shower valve controls that sits on the finished tiled surface.

The box is actually circular with a 138mm radius and it sits behind the tiles and when laying the tiles you need to cut in a hole between 138-142mm, trim the box so it’s flush with the tiles and then lay the Grohe smart control plate on top.

The problem I’m having is sourcing a 140mm tile hole saw to cut into tiles. I have found one one amazon but it needs a tile guide and cannot find tile guides that accept 140mm hole saws. I also found another hole saw on a web site called Starrett which is a Diamond Ceramic and Abrasive Material Hole Saw but is around £140 when you buy the arbour.

Has anyone installed these type of rough in boxes and can advise best approach with marking where to cut and where to source large hole saws for porcelain.

Thanks

Alex

 

[Old Mod]

Once your back box is mounted in to the wall make a template out of 6mm ply so the template sits against something solid like the wall or floor. Lay your tiles out dry on a table how they’re going sit in wall and place template over the top and mark your hole. Use your template as the guide for your hole cutter.
Something like this.

If you want a bit to drill it in one, yes it’ll be expensive, it’s 15mm bigger than our more common 125mm
You could contact @Pro Tiler Tools one of our sponsors and see if they have access to one.
Or you can do it with an angle grinder and diamond blade if you’re confident using one.

 

[Dumbo]

@3_fall lots of secrets come out on that pick

 

[Old Mod]

No secrets, been posted before, you just weren’t paying attention that day! Haha

 

[Qwerty]

Just lay tiles as far as you can and then measure where you need to cut and use an angle grinder with a small Squadro blade. It cuts that radius perfectly.

 

[Albert]

Cut a square with a grinder and finish with pinchers

 

[Old Mod]

Cut a square with a grinder and finish with pinchers

Or get a compass and scribe your radius first. 😀

 

[Simon Dale]

Cut a square with a grinder and finish with pinchers

Old school lol

 

[Bill]

Old school lol

But still works well and quickly......

 

[Old Mod]

I think sometimes we loose sight of the fact that the majority of questions originate from diy’ers looking for a foolproof way of achieving the result they want, and not 20-30yr fitters.
#justsayin! 🙂