tile adhesive not set 3 days later

DIY_Johnny · Post by **DIY_Johnny** » Fri Dec 01, 2017 11:56 am

What a pain in the @ss!

i have tiled up a window reveal and I noticed that the tile adhesive has not set yet. I haven't grouted it in yet so I can see adhesive is soft like putty. Will it harden up over time? Some tiles I can still push down into the adhesive.

I just noticed the adhesive is out of date (just bought it last week from builders depot). Do I have any option here except strip them all off and redo?

dewaltdisney · Post by **dewaltdisney** » Fri Dec 01, 2017 12:33 pm

It is usually the other way around I have found in that older adhesive goes off too quick. It is probably due to moisture in the wall and it is just acting slow to set. The only air that gets in is through the grout lines and the comb tracks in the adhesive. Give it a bit longer and see how it goes. Also, as an experiment, put some adhesive on a tile and leave it to set and see how long that takes.

DWD

Dave54 · Post by **Dave54** » Fri Dec 01, 2017 12:43 pm

What was the temperature?
Here for instance (Don't know if it's the right specific instructions)
https://www.google.co.uk/url?sa=t&rct=j ... B_Dyimlq3A
It says not to use blow +5 degrees C.
Possible a window reveal could be cooler than that.

steviejoiner74 · Post by **steviejoiner74** » Fri Dec 01, 2017 1:01 pm

What size of tiles are they? If they are large format tiles then the adhesive won’t go off.

DIY_Johnny · Post by **DIY_Johnny** » Fri Dec 01, 2017 1:29 pm

Thanks for the response,

Dave, house is warm, easily 15+ i'd say

Steve, only 250 x 200mm (7mm thick wall tiles)

after I posted I lifted off the tiles on the bottom part of the reveal, they came off easily by hand (didn't even need a scraped under there. The adhesive is soft and a touch crumbly. I have cleaned them off and let the tiles dry out, cleaned up the ledge and reapplied BAL (1:1)

the side walls seem sort of ok so I'll not poke about with them, they don't get any movement or interference, so I'll leave them and see how it goes. Maybe they might harden up over the week.

DWD good idea about putting adhesive on the tiles. I'll not grout for a few days and see what happens

DIY_Johnny · Post by **DIY_Johnny** » Fri Dec 01, 2017 7:29 pm

Actually come to think of it? That date on the tub, would that be the manufacturing date ?

Edit: ok looking at Reviews on screwfix, its seems like others are having the same problem.

wine~o · Post by **wine~o** » Sat Dec 02, 2017 5:35 pm

Never used that product and nearly always use a dry addy. However I had one earlier this year using 100mm sq tiles for a small basin splashback; wasn't worth buying a 20Kilo bag, so used this

https://www.screwfix.com/p/mapei-waterp ... -5kg/64982

worked for me

DIY_Johnny · Post by **DIY_Johnny** » Sat Dec 02, 2017 8:19 pm

dewaltdisney wrote:Also, as an experiment, put some adhesive on a tile and leave it to set and see how long that takes.

DWD

Was curious by your suggestion DWD so tried it. left it a room at 20deg heat for more that a day and a half. Adhesive comes straight off and is crumbly and soft. Seems like they made a bad batch

dewaltdisney · Post by **dewaltdisney** » Sun Dec 03, 2017 11:02 am

Ahh, that explains it. Just as well you know for certain and the experiment proves it. Fire off a letter to Mapei. They may well send you a voucher which is not great help to you I guess. But they may want the rest of the tub for test and production tracking and it might help others in the long run.

DWD

JagoGeep · Post by **JagoGeep** » Thu Mar 04, 2021 12:46 pm

just found this thread, I might try this experiment.
I have 2 large tubs of adhesive, about 2 years old, never been opened.

I will open one and see how it looks then try it.

Dave

moderator2 · Post by **moderator2** » Thu Mar 04, 2021 12:50 pm

JagoGeep, Bad form digging up such an old thread. I've locked it.