Introduction
Fiberglass reinforcing mesh plays a key role in thermal insulation systems. If it is applied incorrectly, it can lead to cracks, delamination of layers, or even complete facade failure. In this article, we’ll show you the correct step-by-step procedure for applying fiberglass mesh so the result lasts for years.
Step 1: Surface Preparation
The substrate must be dry, solid, and free of dust and grease.
If the mesh is applied to insulation boards (e.g. EPS or mineral wool), the boards must be properly bonded and sanded.
Fill all joints wider than 2 mm and install anchors if required by the system.
Step 2: Applying the Base Coat
Using a stainless steel trowel, apply a layer of base coat (adhesive mortar) with a thickness of approx. 3–4 mm.
Work only on an area you can process within a few minutes to prevent the material from drying out.
Step 3: Embedding the Fiberglass Mesh
Always embed the mesh into fresh base coat (never onto a dried surface!).
Press the mesh into the material using a trowel so it is fully embedded.
Overlap individual strips by at least 10 cm to prevent cracking at joints.
The mesh should be positioned in the upper third of the base coat layer—not on the surface and not directly on the insulation.
Step 4: Finishing and Leveling
After embedding the mesh, apply an additional layer of base coat to fully cover it.
The final layer thickness should be approx. 5–6 mm, according to the manufacturer’s recommendations.
Smooth the surface and allow it to cure properly (depending on weather conditions and adhesive type).
Common Mistakes to Avoid
Embedding the mesh into dried base coat
Insufficient overlap of mesh strips
Placing the mesh too close to the surface or directly on the insulation
Using damaged or non-certified mesh
Poorly prepared or uneven substrate
Our Tip
Use high-quality, certified fiberglass mesh with sufficient tensile strength and resistance to alkaline environments. Cheap alternatives often do not bond well with the base coat, may tear easily, or lose strength over time.
