We live in a villa built in 1958 that has a basement. We changed the sewage system last Christmas, so now it's time to finish the toilet/laundry room down there. We have just scraped off all the plaster and reached the lightweight concrete blocks. The blocks are quite uneven, and we plan to put tiles on the wall, so I'm wondering if we can even out the irregularities with the adhesive?
Okay. Thanks for the response. I also have a wall that is gypsum board so I will apply primer on it. But when I read about primer, it says it should also be used on plaster and cement. But then the natural ground moisture can't escape? Am I right in skipping the primer on all walls and floors except the gypsum wall?
The main function of the primer is to bind loose particles and to prevent the adhesive from drying out due to the wall absorbing the water in the adhesive before it has time to set. Adhesive that dries too quickly has no strength, just like all other cement-based products that dry out. I would definitely use primer on an old lightweight concrete wall.
Regarding applying adhesive as a filler: yes, it is possible to lay tiles and "fill" at the same time, but it is incredibly difficult in general and especially on walls if you are inexperienced. It is both hard to get it even and the risk of tiles slipping increases significantly if there are thick layers of adhesive. It's better to fill in advance so you can lay the tiles in an even layer of adhesive.
Regarding applying adhesive as a filler: yes, it is possible to lay tiles and "fill" at the same time, but it is incredibly difficult in general and especially on walls if you are inexperienced. It is both hard to get it even and the risk of tiles slipping increases significantly if there are thick layers of adhesive. It's better to fill in advance so you can lay the tiles in an even layer of adhesive.