Share
Hello @charlie0123
If you are worried about the screed not bonding together you can use the Lanko 5L 124 Ultraprime Primer to prime the surface of the first batch of screed. Once the primer cures you can then apply the remainder of the screed. If the drying process is well monitored and the screed is misted properly then it will cure with no visible cracks on the surface. The only reason you would get cracks in the screed is if the drying process was accelerated. Once the screed cures the waterproofing membrane will cover the surface and will prevent water from reaching the screed.
If you have any other questions we can help with, please let us know.
Eric
Hello @charlie0123
If cracks do occur, they can be filled with Earl's 1kg Concremate Expanding Cement before the waterproofing membrane is applied.
Eric
Hi @charlie0123,
Just to clarify, have you already laid a shower screed that has cracked, and you’re looking for repair options, or are you preparing in case cracking occurs? If your screed is cracked, could you share some images? This will help our members provide more tailored advice based on what you're dealing with.
If you're looking for an easy-to-use crack filler, I recommend the Gripset Betta 1L Concrete Crack Filler. It’s simple to apply—just squeeze it directly into the crack.
When applying the screed, the membrane should be installed underneath first. This way, even if fine cracks develop, the membrane will redirect water to the drain, preventing further issues.
As for the timber wedges, they should be removed immediately after applying the screed. At this stage, the screed is still wet, which ensures a strong bond when you fill the gaps. Using the wedges won’t cause cracking. However, if the screed has dried before you remove the wedges, this could result in a poor bond between the old screed and the new one. The key is to complete the process while the screed is still wet—don’t wait for it to dry before filling the wedged areas.
Feel free to reach out if you have any further questions.
Mitchell
Hi @charlie0123,
I apologise. I've just rewatched that section and they do say to wait for the screed to dry before filling the gaps. I wouldn't say that's wrong; there is always more than one way to go about a project. I do see the merits in waiting for it to dry as it's firmer, but since you've already established your fall, I see no reason why you can't fill the gaps before it cures.
Even if you wait for it to dry, I don't think you will have an issue with cracking. Cracking typically occurs in a joint where two larger areas of solid material come together and which can move independently of each other. It's this movement and flex that cause cracks. In this process, you're just filling voids in a substrate that is fixed with no movement.
Mitchell
