Tile adhesive for external use

[kiloran]

About 20 years ago, we had a sunlounge built. It's on a concrete raft about 6m x 5m and it's tiled inside and out with the same tiles, with the outside tiles occupying a band about 1.4m wide on two sides.

We have a problem with the external tiles becoming loose over a few years, presumably due to sun, frost and rain. You can see some of the gaps here:
Imgur - https://imgur.com/WfXPvVi
The internal tiles are fine.

I initially reset some tiles using a Unibond adhesive, which was not very good. About 6 years ago I chatted to the local tile specialists and they recommended BAL Rapidset https://www.bal-adhesives.com/products/rapidset/ but I now find that this is suffering the same problem. I also used a BAL grout https://www.bal-adhesives.com/products/bal-grout/

Any recommendations for a good external tile adhesive which will give a longer effective life?

 

[One Day]

Nothing is really going to withstand repeated soaking, freezing, thawing.
The only way to ensure external tiling lasts is to "manage" the water away.
Using products that will actively shift water away from the adhesive bed such as ditra drain, or non absorbant substrates like water proof backer boards would help.
The biggest help of all would be to make sure tiles are on a solid bed with no voids for water to pool in, and consider epoxy grout to keep water out. Also check your internal corners are siliconed well.

 

[Andy Rhodes]

move to a country where it doesn't rain & snow all the time