Tiling onto bare plasterboard external corners

[john306]

I'm going to be removing 3 lots of stud wall plasterboard and tiles
and replacing with bare plasterboard.



Shower is to be installed in internal corner and I've got Mapei waterproof kit for that, which includes the corner tape so I'm assuming that will be ok.
I'll also be tiling floor to ceiling at a plasterboard external corner so will that need any additional corner supports/preperation before tiling?
Also I've got one pb joint along the long length wall so what prep should I be doing to that too?
Thanks for any help

 

[Richard C]

I'm going to be removing 3 lots of stud wall plasterboard and tiles and replacing with bare plasterboard. Shower is to be installed in internal corner and I've got Mapei waterproof kit for that, which includes the corner tape so I'm assuming that will be ok.

Use only moisture resistant plasterboard in bath/shower rooms. In wet areas your better to use a decent 12.5mm waterproof tile backer than tanked plasterboard; much better solution & the cost difference is negligible once you factor in the tanking which wont protect the back in the case of concealed pipes or shower mixer.

I'll also be tiling floor to ceiling at a plasterboard external corner so will that need any additional corner supports/preperation before tiling?

Not sure I fully understand but shouldn’t do if it’s being covered with tiles.

Also I've got one pb joint along the long length wall so what prep should I be doing to that too?

Fill any gap with adhesive & reinforce tape the join before tiling; ideally tile joints should not coincide with board joints. What size/type/weight tiles are you fixing?

 

[john306]

Thanks Richard,
My question about external corners on plasterboard was because previously I've removed the plasterboard and there was some glavanised? strip covering the 2 edges of the corner floor to ceiling, admittedly this was covered with skim, I just wondered if anything was needed to tie the 2 edges together on bare plasterboard, but your answer to the last question tells me to tape it anyway.

I'll be using 400 x 300 ceramic

 

[Richard C]

That’s a thin coat angle bead you found & only need when the boards are being plastered. Don’t plaster skim if your tiling, it’s not necessary, is a waste of time/money & could be a problem if your hanging large format tiles that weigh more then around 18 kg/sqm.

When tiling or re-tiling, there are many things that can catch you out. With walls, you need to consider tile weights, prep & materials & suspended timber floors need special consideration. I would advise you read the Tiling Sticky & Forum Archive posts before doing any work or buying materials, it could prevent you making disastrous & potentially expensive mistakes. It’s also important to use only quality trade tilling materials of the correct type for your tiles & tile base; cheapo own brand & DIY stuff is mostly crap.

 

[john306]

Ok thanks again.
Final questions for now...
What sized notched trowel should I go for with 400 x 300 Ceramic, sorry don't know the weight as I'm expecting delivery on Friday.
I will be using mapei rapidset.

 

[Richard C]

You should be OK with bare plasterboard (tile weight up to around 28-30 kg/sqm) but it depends on the tile thickness; check before committing. If your overweight, you need a decent tile backer board as I suggested = 40+ kg/sqm. When using powder adhesive (essential with those tiles), you must acrylic prime to avoid any reaction between the cement in the addy & gypsum plaster/plaster board. New plaster board will (should) be fairly flat so you should be OK with a thin solid bed trowel - 10mm (tapering) notches, 5mm deep, at 12.5mm centres.

Where are you buying the Mapei from, not B&Q I hope? They sell Mapei “Buildfix” range (DIY) which is not the same as Mapei trade products. Use flexible grout.

 

[john306]

I've read before about the B&Q mapei adhesive so will leave that well alone and get 20kg Keraquick white from a tile store.
Thanks for info on trowel