Render & ETICS Facades
A rendered facade combines insulation and aesthetics in a single system. Learn about ETICS (External Thermal Insulation Composite Systems), material selection, reinforcement mesh and consumption calculations to European standard EAD 040083.
Render systems — comparison
| System | Binder | Base coat use | Finish coat use | Advantages |
|---|---|---|---|---|
| Mineral-based | Cement / lime | 5–8 kg/m² | 2.5–3.5 kg/m² | Vapour-open, non-combustible |
| Acrylic-based | Acrylate | 6–7 kg/m² | 2.0–3.0 kg/m² | Flexible, many textures |
| Silicone-based | Siloxane | 6–7 kg/m² | 2.0–2.5 kg/m² | Hydrophobic, self-cleaning |
ETICS build-up — cross section
From existing wall outward:
Reinforcement mesh — technical requirements
- Material:Alkali-resistant glass fibre (AR-glass)
- Weight:Minimum 145 g/m² (standard); 160 g/m² in wind-exposed locations
- Overlap:Minimum 100 mm (4 in) in all directions
- Extra reinforcement:200 mm (8 in) diagonal strips at all corners and openings (window angles)
- Position in base coat:At least 2/3 of the thickness from the outer face — fully embedded
- Mesh type:System-certified only — foil mesh is not acceptable
Step-by-step — ETICS installation
The substrate must be stable, dry and clean. Remove loose render, salt efflorescence and organic growth. Prime absorbent surfaces with a bonding primer.
Work within the limits on the product data sheet — typically something like not below ~5°C (41°F) or above ~30°C (86°F), out of direct sun and out of strong wind (e.g. above ~6 m/s, roughly 13 mph) — but the exact figures and minimum cure temperature vary by product, so follow the manufacturer's instructions.
Apply system adhesive using dots-and-perimeter method (minimum 40% coverage) or full-coverage technique. Fix boards in a brick-bond pattern — no continuous vertical joints.
Drive 6 mechanical fixings/m² (disc anchors) once adhesive has cured (24–48 h). Also fix perimeter with at least 2 fixings per linear metre at edges.
Apply base coat with a steel float to approximately 3–4 mm, about ⅛ in. Immediately press in the glass-fibre mesh so it is fully embedded. Work top-down to avoid run marks.
Total thickness including embedded mesh: 4–6 mm (⅛–¼ in). Allow to cure at least 3 days.
Apply system-certified primer by roller or brush. Allow to dry per data sheet (normally 2–12 hours). Primer ensures adhesion and evens porosity.
Apply finish coat (1.5–3.0 mm for fine plaster, up to ⅛ in; 2.5–5 mm — ⅛–¼ in — for heavier textures) with a steel float. Work the desired texture with a plastic or wooden float within the open time (typically 15–30 min).
Always work across a full scaffold-level lift without stopping — joints will show.
Consumption table
| Component | Low | Medium | High |
|---|---|---|---|
| Base coat | 5 kg/m² | 6.5 kg/m² | 8 kg/m² |
| Finish coat | 2.0 kg/m² | 2.8 kg/m² | 3.5 kg/m² |
| Primer | 0.1 l/m² | 0.15 l/m² | 0.2 l/m² |
| Mesh (incl. overlap) | 1.1 m²/m² | 1.2 m²/m² | 1.3 m²/m² |
| Adhesive | 3 kg/m² | 4 kg/m² | 6 kg/m² |
Regulatory requirements
A rendered facade must withstand precipitation, moisture and mechanical loads throughout its service life. Design for the wind-driven rain exposure and wind loads applicable at the specific site.
Reaction-to-fire performance of a rendered facade is a property of the complete, certified ETICS, not of the insulation board alone. Combustible insulation such as EPS is restricted near boundaries, on taller buildings and on certain building types — where higher fire performance is required, a mineral-wool ETICS or other non-combustible build-up may be needed. The thresholds (height, distance to the boundary, required class) vary by country; always check your local fire/building regulations and use a certified system for that building.
Common mistakes
- ✗Working in direct sunlight — base coat dries too fast and cracks
- ✗Base coat too thin or mesh not fully embedded — glass-fibre ETICS mesh does not rust, but if it sits proud or against the insulation it cannot control cracking and impact; keep it embedded in the outer third of a base coat of the system thickness
- ✗Aligned insulation board joints — thermal bridges and risk of render cracking
- ✗Open joints between insulation boards — never fill them with render (it bridges heat and cracks). Push boards tight; fill any wider gaps the way your ETICS system specifies (slivers of the same insulation, or a low-expansion PU foam, not render) and follow the system gap tolerance rather than a fixed figure
- ✗Mixing components from different system suppliers — system warranty is void and product performance uncertain
- ✗Missing diagonal mesh at window/door corners — cracks within months
Calculate render and ETICS
Use the calculator to estimate kg base coat, finish coat, mesh and primer quantities.
Open render calculator →Tools you'll need
The kit this job actually calls for, and whether it's worth buying or renting for one weekend.
- Plasterer's trowel
Lays on and flattens render and finish coats.
Buy 25–70 € - Plasterer's hawk
Carries the compound in your other hand; a mud pan is the alternative.
Buy 15–35 € - Sponge / plastic float
Brings up the texture once the coat has taken up.
Buy 10–30 € - Paddle mixer
Mixes adhesive, grout, render and levelling compound lump-free.
Buy 50–150 €Rent 12–25 €/day - Notched trowel
For bedding the reinforcing mesh into the base coat.
Buy 8–25 € - Snips
Cuts reinforcing mesh, beads and metal profiles.
Buy 10–25 € - Mixing tub
Wide, shallow tub for mortar, render and larger batches.
Buy 15–35 € - Screed board / straightedge
Rules the base coat flat between beads.
Buy 20–60 € - Safety glasses, gloves and dust mask
Silica dust from tile, block and render is the real hazard on these jobs — an FFP3 mask, not a paper one.
Buy 15–40 €
Prices are indicative for DIY-grade tools and vary a lot by brand and region — treat them as a budgeting starting point, not a quote. Rental rates are per day from a typical tool rental shop.
Frequently asked questions
What is ETICS and is it code-compliant?
ETICS (External Thermal Insulation Composite System) is a CE-marked facade system for exterior insulation with render finish. Systems are approved to EAD 040083 and CE-marked by manufacturers. Widely used across Europe and increasingly in North America as EIFS.
How much base coat render do I need per m²?
Mineral base coat: 5–8 kg/m² (depending on substrate flatness). Acrylic and silicone systems: 6–7 kg/m². Finish coat (thin-coat): 2.0–3.5 kg/m² depending on texture. Always check manufacturer data sheets.
What reinforcing mesh is required in ETICS render?
Alkali-resistant (AR) glass fibre mesh, minimum 145 g/m², fully embedded in the base coat. Overlap joints by at least 4" (100 mm). Add 200 mm diagonal strips at all window and door corners.
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Turn this guide into a plan
Get exact quantities and costs for your own measurements, build an itemized shopping list so you don’t overbuy, and use the PDF to collect quotes from contractors.