A well-installed ETICS is not recognised on handover day: it is recognised ten winters later, when the facade is still flat, dry and free of anchor "ghosts". The difference is not made by the materials — it is made by the hand that installs them, and by the time that hand is given.
External thermal insulation (ETICS) is the most common way to upgrade existing buildings. It wraps the building in a continuous shell that removes thermal bridges and moves the dew point outside the wall: the envelope stays warmer in winter and cooler in summer, protected from the thermal shocks that crack renders. It is the basis of almost every energy-efficiency retrofit.
click a beat · arrow keys ← → walk the site · dashed pauses are the chemistry at work
The detail of the craftthe straightedge and the pull test
Cleaning, levelling and flatness check of the wall. Removal of loose parts and primer application.
"Run your hand across the wall: if it comes back white with dust, that wall isn't ready — and no primer works miracles."site notebook — editorial synthesis
Before starting
ETICS wraps the building from the outside: the masonry stays warm, thermal bridges close, and the walls' mass works for you — holding heat in winter, delaying it in summer.
Qualitative synthesis of the thermal behaviour — up to −40% heating demand on uninsulated envelopes (depends on building and climate; design verification via the "Legge 10" report).
The choice that shapes everything
Conductivity says how much it insulates at equal thickness; but in an ETICS fire, summer behaviour and water matter too. No insulation wins on everything: you choose for the building, not for the price list.
Fire decides before you do: mineral wool is non-combustible (Euroclass A1) and above certain heights wool fire breaks are standard practice even in EPS systems. Summer flips the ranking: the EPS that wins in winter is last for phase shift, while wood fibre — which gives up a little λ — buys half a day of delay against the heat. Mass has a price: fibre and cork weigh more and demand more careful anchors and fixing design.
The real calendar
The wet works of ETICS — adhesive, base coat, finish — live in a narrow window: below +5 °C the chemistry stops, above +30 °C (or in full sun) the water escapes before it is needed.
Exact thresholds are set by the system datasheet: this is the good-practice frame shared by industry guidelines.
Yes, if air and substrate stay above +5 °C even at night while coats cure — which, in half of Italy, is not true in winter. Winter additives help the adhesive, not the finish: the finishing phase is the one the calendar rules most.
It depends on the build-up: mineral wool and wood fibre with silicate finishes stay highly vapour-permeable; EPS less so. The design rule is that permeability should grow towards the outside — the mistake is sealing a damp wall behind a layer that lets nothing out: fix the moisture first, then insulate.
Properly installed ETICS have passed 30–40 years in European monitoring (the first Berlin systems from the 1960s are still in service). Durability lives almost entirely in phases 01 and 04: a sound substrate and a correct reinforced base coat.
Above the ground floor you need scaffolding: phases 02 to 05 demand horizontal continuity ("wet on wet" along the same bay) that mobile towers cannot keep. And scaffolding belongs to safety costs (PSC), not to the panel price.
Informational links to the regulatory framework. Always verify the current text on the official source.