How Do I Break Down Keraquick

[nick giles]

Backer board very reasonable compared to a fail. In the olden days I'd had a few fails on ply either de laminating or just throwing a tile for no reason live surface. No fails on any of the dead surfaces.

my only fail with ply was an 18mm bath panel which i forgot to prime... banana within 2 days. but there is my proof that 'live' material works.... ply works.... a bath panel if primed on both sides and then tiled can last for years and years standing vertical with little support....
as I am experiencing when the keraquick sticks to the plasticiser primer..... its a total swine to break the bond.

 

[LM]

im being double macced

Not at all mate, just trying to steer you in the right direction, you've asked for ideas and in doing so we're simply pointing out that quite probably the fundamental failure here is the ply.
Plywoods a today have all sorts of problems one of the main ones being that a lot of cheap stuff comes in from Asia and is coated in releasing agents to prevent the sheets melting together in the heat of transport and tile adhesive dosent go very well with releasing agents, that's only one issue with it. Plywood and underfloor heating is a hell of a gamble in itself due to the contraction and expansion with temperature fluctuation. At the end of the day you'll do your own thing, we're only trying to point out why we as professionals don't like ply as a substrate and also the problems that you might face

 

[nick giles]

my only fail with ply was an 18mm bath panel which i forgot to prime... banana within 2 days. but there is my proof that 'live' material works.... ply works.... a bath panel if primed on both sides and then tiled can last for years and years standing vertical with little support....
as I am experiencing when the keraquick sticks to the plasticiser primer..... its a total swine to break the bond.

marine ply is more expensive but good.... i take all your points on board (ply board ?) thanks guys.. i now work for a firm so if i can find an excuse to try out backer boards, i will... cheers.

 

[AndY mac]

Mission accomplished. And it's good night from me

 

[Stef]

I'm in Glasgow tomorrow morning, do you want me to come look at the job & give you my take on why it's partly failed??

 

[LM]

my only fail with ply was an 18mm bath panel which i forgot to prime... banana within 2 days. but there is my proof that 'live' material works.... ply works.... a bath panel if primed on both sides and then tiled can last for years and years standing vertical with little support....
as I am experiencing when the keraquick sticks to the plasticiser primer..... its a total swine to break the bond.

Your only supposed to prime the back face and edges of ply with an SBR to prevent moisture ingress, that is of corse if you've used WPB or Marine grade ply

 

[nick giles]

Your only supposed to prime the back face and edges of ply with an SBR to prevent moisture ingress, that is of corse if you've used WPB or Marine grade ply

you need to prime the tiled surface also to let the cement based glue bond to the plasticised ply surface.

 

[nick giles]

I'm in Glasgow tomorrow morning, do you want me to come look at the job & give you my take on why it's partly failed??

ho stef, the job is in Musselburgh edinburgh.... really appreciate the offer.. again I know what the failure is... its the horizontal movement between the 25mm ply boards expanding and contracting. lack of overboard. however if I decide to rip it all up , I am paying someone else to do the new job so you might want to quote going to try to get client to put up with it for a year though until i can save some money..... pass me a gun with the safety off..... never ever being a builder again, im a meticulous bathroom fitter... dealing with subbies and lazy ones at that..... no thanks.

 

[nick giles]

i will post a photo of the diabolical disaster.... surprised no one asked for one i will stick one on after i have tried a temp patch on saturday.. before and after.

 

[One Day]

Talking with some very top-end joiners who fit out banks head offices, footballers mansions etc...
They have just had a massive failure on ply. Top quality 18mm birch ply.
Warnings were circulating about ply years ago, and under the radar it seems that all the decent stuff (as old WBP and marine grade appeared to be) has now been re-certified.
The WBP and marine grade we get now is utter utter rubbish.

Worth a read for all you ply lovers!
Plywood - Getting it right - http://stta.org.uk/News/gettingitright.html

 

[Spud]

I was asked to tile a shop in bond street nice jewellery shop, got there ready to start and the shop fitted had nailed fown 6 mm ply ready for tiling with 60x30 gulf stone , it was moving as I walked across it.
I spent a couple of minutes trying to explain it would fail but the guy wasnt interested and thought I was just trying to talk up the price,
I just said okay then, thanks but I wont be doing the job then and left,
It cost me a a days money for myself and the tiler and we had to move work forward

 

[aussie tiling]

I dont understand how you think overboarding with 6mm ply will be any beneficial? If anything you want to strengthen floor with a 6mm hardie glued and screwed with flexi adi, hardie comes from aus and weve been doing it for years and years with no problems at all as long as your substrate is sound. I have even for fast track installation instead of screeding layed 12mm hardie onto a concrete floor just like tiling, you have to prime the hardie first to stop it curling thats only the 12mm though.

 

[Stef]

I dont understand how you think overboarding with 6mm ply will be any beneficial? If anything you want to strengthen floor with a 6mm hardie glued and screwed with flexi adi, hardie comes from aus and weve been doing it for years and years with no problems at all as long as your substrate is sound. I have even for fast track installation instead of screeding layed 12mm hardie onto a concrete floor just like tiling, you have to prime the hardie first to stop it curling thats only the 12mm though.

Hardie shouldn't be used on a concrete floor.
If I was going to do that then I would be using a thermal board

 

[One Day]

Hardie shouldn't be used on a concrete floor.
If I was going to do that then I would be using a thermal board

I think they allow(ed) it in Australia. UK James Hardie say NONO!

 

[nick giles]

Hardie shouldn't be used on a concrete floor.
If I was going to do that then I would be using a thermal board

been thinking about this thread all day.... simply put... i have never seen a tile lift from a well installed, primed section of plywood with a decent adhesive and a well laid tile. as i said, the bastard is in the number of screws you need to go through to make the ply overboard totally inflexible... and in response to aussie tiler.... you are effectively creating a cross ply section with overboarding which makes it vastly stronger. like anything, if it is done well it will last.