Travertine on plaster / breezeblock walls

[DazJWood]

I will be tiling my bathrooms walls soon.

I have two walls that are stud walls and I have used Hardiebacker board for these. The other two walls are breezeblock with what looks like a plaster skim over the top.

I have bought travertine tiles which are around 10-12mm thick (I am not at home and can't remember the exact thickness, but I'm sure they are 12mm).

Looking at the weights it appears that I can't (or shouldn't) tile directly on to the plaster as I will be over the recommended guidelines.

Is my best solution to remove the plaster back to the breezeblock and then fix hardieback board to these walls? If so what is the best way of applying them? Do I use some form of adhesive combined with screwing into the breezeblock?

I'd appreciate some advice.

Thanks in advance,

Daz

 

[Onlinetiler]

You're right with the weight guidelines Daz.
You could just mechanically fix the hardibacker over the skimmed walls to save you chopping them back to the blockwork.

 

[DazJWood]

You're right with the weight guidelines Daz.
You could just mechanically fix the hardibacker over the skimmed walls to save you chopping them back to the blockwork.

Thanks for the reply!

I would do this but I've now fixed in my bath and I'm sure (from memory, I'd need to check though) that the extra thickness of the hardiebacker board then the tiles would take the thickness over the bath rim or very close at least. If it doesn't then I will certainly go for your suggested method. Would or should I use any form of adhesive underneath to take up any wall irregularities? Or just mechanically fix it?

If I have to take the wall back to breezeblock what is the best method for attaching the backerboard? There will be irregularities for sure in the breezeblock level.

Thanks again,

Daz

 

[paulyoung666]

it might be easier to move the bath

 

[DazJWood]

But I still need to know the best way to fix the backerboard?

On the Hardie site it only has reference to fixing onto a masonry wall using 6mm of tile adhesive plus mechanical fixing. Would this be the same to fix over plaster?

Thanks,

Daz

 

[Scott]

You could use board adhesive to overcome the uneven walls but you will still have to screw them to the wall. I use concrete screws so you dont need to plug and screw, just pilot hole and drive them in.

 

[DazJWood]

You could use board adhesive to overcome the uneven walls but you will still have to screw them to the wall. I use concrete screws so you dont need to plug and screw, just pilot hole and drive them in.

Thanks!

Excuse me for being thick! But what's board adhesive? Could you provide a link? And also what are concrete screws? Are they like frame fixings?

Thanks again!

 

[doug boardley]

why not take it back to the brieze block and dot and dab plasterboard (you may have to check tile weight tho' to be on sasfe side)

 

[doug boardley]

just nicked this out of Oli's Bible

Substrate weight ratings

A common question, how much weight can my wall support, here are the reccommended max weight ratings in KG / m2

Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fibre Board.....................40KG

Remeber to factor in the weight of the tile / m2 AND adhesive and grout

Grout.........2KG / m2
Adhesive....4KG / m2

 

[DazJWood]

Lol thanks for the specs but I know all that hence the question in the first place.

Just need to know how best to attach the backboard and using what adhesives.

thanks!

 

[doug boardley]

what's the weight of your trav?

 

[DazJWood]

It falls into the 35Kg/m2 catagory with the adhesive.

 

[Onlinetiler]

With regards the actual fixing of the boards to the block work - I've only ever been advised to mechanically fix, but being a belt and braces kinda chap I actually sealed the wall with a bonding agent (think it was BAL, but getting too old to know for sure:lol and then used a flexible cement based adhesive and actually bedded the boards onto that before drilling.
I don't know the tech spec for the product well enough to know whether it was right or wrong, but worked like a dream and I pity any poor sod who might want to change those tiles in the future.

 

[DazJWood]

With regards the actual fixing of the boards to the block work - I've only ever been advised to mechanically fix, but being a belt and braces kinda chap I actually sealed the wall with a bonding agent (think it was BAL, but getting too old to know for sure:lol and then used a flexible cement based adhesive and actually bedded the boards onto that before drilling.
I don't know the tech spec for the product well enough to know whether it was right or wrong, but worked like a dream and I pity any poor sod who might want to change those tiles in the future.

Hey thanks for the reply.

What fixings did you use (or would you use)? Would it be the frame type fixings, or would you offer the board up to the walls, drill through the board and wall and then remove and use rawl plugs?

Thanks,

Daz

 

[DazJWood]

Also, you have said fixing onto block work, but I wanted to fix over the plaster, or should I remove this?

 

[Onlinetiler]

Drilled and plugged Daz.

Not the easiest way for sure but it meant I could guarantee the screw heads would sit flush and like I said before, they're there to stay now.

 

[DazJWood]

Drilled and plugged Daz.

Not the easiest way for sure but it meant I could guarantee the screw heads would sit flush and like I said before, they're there to stay now.

Thanks!

I think I'll take it back to the breeze block and fix in the same manner.

How many screws would you say you were attaching per board?

And would they just be normal drywall or Hardie screws that you've used?

Thanks again,

Daz

 

[DazJWood]

Also what's the best rawl plugs to use for these!

Sorry with all the questions (and probably dumb questions) but I'd rather go with the right fixings based on the fact that you've done it and it works

 

[jimmy495]

Hi daz if it was me doing this job and if you are going to take it back to the breezeblock walls i would use lats and boards fix the lats to the wall so they are true and you no you have a good fixing then board

 

[DazJWood]

Hi daz if it was me doing this job and if you are going to take it back to the breezeblock walls i would use lats and boards fix the lats to the wall so they are true and you no you have a good fixing then board

Hey thanks Jimmy.

Can I be really thick?, (which isn't hard!). When you say lats I'm presuming you mean battens (only thinner?). What sort of size would you use? Or rather should I say what sort of width would I get away with using? Ideally I need to keep the distance away from the wall to a minimum.

Also what would be the advantage of this method over fixing to the breeze block without the battens?

Thanks for your response!

Daz

 

[DazJWood]

Anyone any advice?

 

[Alan.P]

If your struggling for depth then take it back to block, use a flexible tile adhesive or proper dot and dab adhesive, to hold the board up whilst you level / plumb them, once the adhesive is set, 3 hrs for a rapid set, next day for a standard set and board adhesive, drill, plug and screw the boards with screws of choice, making sure the heads don't pull through the board of course.

 

[jay]

hi why not remove plaster from blockwork then lay tiles

 

[DazJWood]

If your struggling for depth then take it back to block, use a flexible tile adhesive or proper dot and dab adhesive, to hold the board up whilst you level / plumb them, once the adhesive is set, 3 hrs for a rapid set, next day for a standard set and board adhesive, drill, plug and screw the boards with screws of choice, making sure the heads don't pull through the board of course.

What fixings would you use for this? Frame / Hammer fixings? Have you a link to the ideal ones to use?

hi why not remove plaster from blockwork then lay tiles

Tile directly onto block? Is this feasible?
I doubt the blockwork underneath would be level. It isn't under the bath. I'd have a right game building up tile adhesive to make up for the differing levels.
Thanks,
Daz

 

[Alan.P]

Hardibacker screws

LINK

 

[jimmy495]

daz if you use lats you no how good they are fixed and how meay screws you put in i think i would trust screws and lats more then dot and dab
but up to you mate:8:

 

[DazJWood]

Hardibacker screws

LINK

Yeh these are the screw I used for attaching the boards to stud walls, but you said to plug and screw them.

Are you talking about drilling the boards once they are attached, inserting a rawl plug into board and wall and then screwing in these fixings?

daz if you use lats you no how good they are fixed and how meay screws you put in i think i would trust screws and lats more then dot and dab
but up to you mate:8:

I won't be dot and dabbing which ever method I use. You shouldn't dot and dab Hardiebacker board nor any other heavy cement board. But am considering 6mm tile adhesive and mechanical fixing.

I am still not clear what you mean by lats. What size are these? I don't want to be coming off the wall and further than I have too ideally.

Thanks,

Daz

 

[jay]

What fixings would you use for this? Frame / Hammer fixings? Have you a link to the ideal ones to use?

Tile directly onto block? Is this feasible?
I doubt the blockwork underneath would be level. It isn't under the bath. I'd have a right game building up tile adhesive to make up for the differing levels.
Thanks,
Daz

yes its do able you may need to straiten walls first with adhesive

 

[White Room]

just nicked this out of Oli's Bible

Substrate weight ratings

A common question, how much weight can my wall support, here are the reccommended max weight ratings in KG / m2

Plaster Skim on Plaster Board........20KG
Skim and Set Plaster...................28KG
Plaster Board.............................32KG
Sand and Cement.......................40KG
Cement Backer Board..................55KG
Hardibacker Board.......................45KG
Lightweight Tile Backer Board........40KG
Glass Reinforced Cement Sheet.....50KG
Gypsum Fibre Board.....................40KG

Remeber to factor in the weight of the tile / m2 AND adhesive and grout

Grout.........2KG / m2
Adhesive....4KG / m2

Personally I would treat float and set as 20kg

 

[DazJWood]

I have contact Hardie and they replied with a pdf file detailing how to attach Hardiebacker 250 (6mm thick) board to masonry walls (brick or blockwork).

They detail 6mm tile adhesive together with masonry anchors.

I was intending to use Hardiebacker 500 (12 mm thick) for my walls as I wasn't aware that the 6mm could be used. It states in the pdf that the maximum load carrying weight is 45kg to this would be fine for my travertine tiles.

Has anyone used the 6mm boarding for this purpose or do you think I should still stick with the 12mm?

Also, I have now taken the plaster off the wall back to the blockwork. It isn't particularly good blockwork and the levels are off in places. Do I just build up the levels using tile adhesive prior to attaching the boards?

Thanks all,

Daz