Backer boards for large format tiles

[LinearPancakes]

We're having 100x100 porcelain tiles on most of our bathroom walls. They're only 6mm thick though, so hopefully not as weighty as some.

 

Our builder was planning to use moisture board throughout. But our tiler recommended jackoboard for the larger format tiles.

 

After some research, a lot on this forum, it seems like we should be ok with the moisture board as long as we carefully tank the wetter areas, e.g. showers. But I'm not sure if the larger format/porcelain tiles would be better supported/easier to adhere to the cement facings on a board like jackoboard. Cc @Nickfromwales

 

I'm a little reluctant to use XPS based boards as it doesn't seem like they will provide much sound proofing, despite the marketing claims, given the lack of density. In some places we would have tiles on either side of a stud wall, which would seem a particular issue sound-wise.

 

Any advice appreciated!

[nod]

Pretty easy one 

As a rule we don’t go over 20 kg m2 for PB Some builders drive us crazy by insisting walls are skimmed prior to tiling Then it drops down to 15 m2 

The weight will be printed on the side of the box Check your tile thickness 6 is very thin 

 

If your worried about sound use a 15 mil moister soundboard 

[LinearPancakes]

Many thanks @nod, I'm checking the weight, and good tip about not skimming the tiled areas.

 

Is there anything about larger format tiles generally that would make a cement faced board preferable? Easier to adhere?

 

I'd seen you like to use the BG tile backer board, with a more suitable facing. Would you say tanked moisture boards are about equivalent?

 

Thanks!

[Nickfromwales]

First question is, have the studs been installed at 400 o/c? 600mm centres is no good for a bathroom.

If so, I’d say MR PB at 15mm thickness and tanking will be bombproof 💣  . That’s how I’ve done every single bathroom that I have been in charge of the specification for, and that’s served me well for over 25 years of bathroom fitting / tilling. 
Just make sure you have a PB ( drywall ) screw ( 32mm long ) going into the studs every 120mm and it’ll be rock solid. 

[LinearPancakes]

Many thanks @Nickfromwales. I'll check the centres of the studs later today. They "look" like 400 from my pictures, but can't be sure.

 

Do you think 12.5mm mr pb would still be strong enough, if studs are at 400 centres, even if not perhaps bomb proof? 😅 Got a few areas that are pretty tight and every mm will help. Our tile provider informed they're only 14kg/m2, so if not skimmed we should be ok weight-wise.

 

Sound-wise, I'm happy with regular pb acoustic properties. We have soundboard on the bedroom side anyway. It was more not wanting to have the low density of XPS only in some places.

[Nickfromwales]

2 hours ago, LinearPancakes said:

Many thanks @Nickfromwales. I'll check the centres of the studs later today. They "look" like 400 from my pictures, but can't be sure.

 

Do you think 12.5mm mr pb would still be strong enough, if studs are at 400 centres, even if not perhaps bomb proof? 😅 Got a few areas that are pretty tight and every mm will help. Our tile provider informed they're only 14kg/m2, so if not skimmed we should be ok weight-wise.

 

Sound-wise, I'm happy with regular pb acoustic properties. We have soundboard on the bedroom side anyway. It was more not wanting to have the low density of XPS only in some places.

If you can tell me you’ll notice gaining 2.5mm then I’ll buy the drinks 😜. You’ve asked about acoustics, the 15mm PB will help. 
 

In case you’re snowed under, I’ll put this into context; eg that’s less than the thickness of 4 credit cards.

[Temp]

We have stone in our bathrooms and our builder was keen to use 12.5mm Hardibacker board. It's quite hard to cut but I like it now as it's great to fix into. 

[nod]

8 hours ago, LinearPancakes said:

Many thanks @nod, I'm checking the weight, and good tip about not skimming the tiled areas.

 

Is there anything about larger format tiles generally that would make a cement faced board preferable? Easier to adhere?

 

I'd seen you like to use the BG tile backer board, with a more suitable facing. Would you say tanked moisture boards are about equivalent?

 

Thanks!

I use the bg backer on most jobs

out performs cement 

and easier to handle and cut