old bathroom ply

[Fred]

Started a job yesterday. 10m2 bathroom walls. The client stripped the old tiles off and ensured all old addy was off as well. The house was built in the early 60's and the old ply is present on one wall, with a shelf etc.

I acrylic bonded the walls. I used Mapei slow set flexi. To my horror today, two tiles came off! On inspection of the ply, I found the outer skin had buckled! I had to cut it out with a stanley.

What would have caused this to happen?

 

[Gazzer]

Was it WBP ply? probably not, more like shuttering ply. This is the reason i believe wood has no place in wet areas, its a live material and even after all these years it can change.

 

[kilty55]

i had probs with ply a while ago from b and q like this the outer sheet had split and buckled was meant to be wbp ply as well i would assume moisture has done this over time,maybe best to fix it 1st?

 

[doug boardley]

I'll bet it had previously been pva'ed to Fred

 

[DHTiling]

What would have caused this to happen?

Moisture from the slow setting adhesive.....rapidset would have been better but not a fan of ply on walls...

 

[sWe]

Was it WBP ply? probably not, more like shuttering ply. This is the reason i believe wood has no place in wet areas, its a live material and even after all these years it can change.

Well said. Over here, insurance is void if you tile onto wooden substrates in bathrooms/wetrooms.

 

[CBTC]

I know from the merchants that the whole hardwood ply supply chain has altered a lot in recent years, affecting prices all along the line. Certainly the quality of a lot of the stuff is poor even then and delamination common. Buy with caution.
In the case mentioned I'd have thought twice about fixing to the exisiting background.

 

[Gazzer]

Well said. Over here, insurance is void if you tile onto wooden substrates in bathrooms/wetrooms.

I dont think it will be long before insurance companies over here wise up to this.

 

[Fred]

I dont think it will be long before insurance companies over here wise up to this.

The plumber tried to convince the client to have it all ripped out and re-done...........:mad2:

 

[Gazzer]

The plumber tried to convince the client to have it all ripped out and re-done...........:mad2:

And whats wrong with that??

 

[wayne]

three little words; no more ply.

 

[Perry]

Moisture from the slow setting adhesive.....rapidset would have been better but not a fan of ply on walls...

seen it before Dave loads of times always use rapid if you canete

 

[smurf21]

No More Ply:hurray::hurray::hurray:

 

[Fred]

And whats wrong with that??

as I said, he tried to convince the client. It was the right way, but some times, you can't budge a client, even with all the experience you have.

 

[Fred]

seen it before Dave loads of times always use rapid if you canete

I did change to rapid, but couldn't get hold of keriquik whick is slower in the bucket, ended up with granfix white flexi, evil stuff.