Can timber wedges make the shower screed prone to cracking?

[charlie0123]

I was reading and watching Bunnings' "How to screed a shower base" and have a question here:Can the use of timber wedges make the shower screed prone to cracking along the wedge lines? It's because the wedges are removed and the gaps are filled after the screed is dry (12 hours later), and the new screed fill may not attach to the existing screed well.

https://www.bunnings.com.au/diy-advice/home-improvement/baths-showers-toilets/how-to-screed-a-shower...

[charlie0123]

OK, put this way to make the question easier: If there is a hairline crack in the new screed due to shrinkage (hot weather), can I use the product (Dunlop 5kg Ardit Rapidset Repair Mortar)?

[JacobZ]

Hi @charlie0123,

Yes, you can, but you may need to add a bit of water to reduce its thickness as it is fairly thick.

Alternatively, the Gripset Betta 1L Concrete Crack Filler that was mentioned above is already low-viscosity and would be fine for this kind of repair.

Let me know what you think.

Jacob

[MitchellMc]

Hi @charlie0123,

Yes, you can. However, you might find it difficult to push this or any mixer into a hairline crack. It would certainly work on cracks that have opened up enough to allow mixture to be pushed into them.

Mitchell