Why are there micro cracks on the facade being insulated with EPS?
A couple of days ago I made a reinforcing layer. Each sheet is fixed with 5 mushrooms, joints are foamed, seams are grouted. The mesh is 160 grams per m2. Mesh was sunk into the adhesive. The side was sunny, but everything was covered by a tent. After drying on the same day the levelling layer was applied. The tent was hanging for about two days. But after removing the tent, when the sun came out, micro cracks were visible. It looked like the reinforcing layer couldn't withstand the temperature changes. Or is it something else?
Answers
Mesh 160 is not designed for EIFS.
There are many reasons. The layer is excessive, the mix is wrong, the adhesive is of poor quality.
For insulation system, mesh with a tensile load (on the base and weft 2000N) is 165gr.
The quality depends on the manufacturer. It is likely that the top layer began to "dry out" / give up water very quickly. And the deeper layers were still wet, with the release of moisture and ripped.
Please clarify the order of your actions:
— applied a layer of glue (how thick?)
— Drowned the mesh (did it remain visible?)
— and then reapplied glue after the tear?
How thick was the overall layer of glue?
Violation of installation technology!
Option №1 - Let's call it "at once". Glue is applied – the grid is recessed – the surface is leveled. (The total thickness of the layer of 3-5 mm, there are exceptions, but it's a separate subject)
Option number 2 (allowable, but it is not quite clear why it should be applied) - "in two passes."
Apply the adhesive – embeds the grid – the surface is aligned. The second step (after about a day) primed – applied a second layer of glue. You still have a high risk of delamination of the first and second layer! (cracks are not the main problem)