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Facade paintingPainting a facade is the fastest way to make a home look cared for again. It is also the job that most often tackles the wrong problem. Below you will find which paint suits which facade, why vapour permeability matters more than colour, and when we advise you not to paint at all.
Every wall gives off moisture continuously: construction moisture, rain that has penetrated, vapour from inside the home. A facade paint has to let that through. If it does not, it becomes the lid on a pot that keeps on steaming.
The moisture stays trapped behind the paint layer. First you see blisters, then the paint flakes off, and after that damp patches appear on the inside. In winter the trapped moisture freezes and pushes pieces of brick or render away. At that point you are not looking at one lost paint job, but at a facade renovation.
The European standard EN 1062 classifies facade paints by vapour permeability: V1 is highly vapour-open, V2 moderate, V3 vapour-retarding. There is also a class for water absorption, from W1 to W3. The combination you want on a facade is V1 with W3: vapour gets out easily, rain gets in with difficulty.
For painting a cavity wall that has been insulated after construction, Buildwise applies a concrete requirement: a paint with a vapour diffusion resistance sd of no more than 0.05 m, and even then only if the facade is in good condition and not heavily weather-exposed. That is stricter than the ordinary V1 class.
Where there are damp problems, paint is rarely the answer. Buildwise stresses that you first remove the cause — a water-repellent treatment does not miraculously solve every damp problem. During the site visit we look at where the moisture is coming from before we talk about colours.
The wrong paint on a healthy facade does more damage than no paint at all.
— VediWorksIt is not your taste that determines the type of paint, but what lies underneath. A paint that does not suit the substrate will either peel off or seal the facade — however expensive it was.
| Paint | Vapour-open | Water absorption | Adheres to | Strong point |
|---|---|---|---|---|
| Silicone resinsiloxaneMost versatile | Class V1 – V2 | Low (W3) | Practically any substrate, including existing render | Combines vapour transport with strong water and dirt repellency; high colour stability possible |
| Silicate paintmineral, potassium silicateOn mineral facades | Class V1 — the highest | Low (W3) | Mineral substrates only: render, lime, concrete, masonry | Bonds chemically with the substrate instead of forming a film; the highest colour stability |
| Acrylic / dispersionsynthetic resin-boundLimited | Class V2 — noticeably more closed | Low (W3) | Practically everything, including old acrylic paint | The widest choice of colours and the lowest price — but the wrong choice on a facade that has to breathe |
| LimewashtraditionalNiche choice | Very high | High | Lime-bound render and old masonry | Authentic appearance on historic masonry; needs maintenance more often than the modern systems |
Classes to EN 1062: V1 = sd less than 0.14 m (highly vapour-open), V2 = sd 0.14 to 1.4 m, V3 = sd greater than 1.4 m. Water absorption: W3 = lowest absorption. The exact values are given per product in the technical data sheet. Rule of thumb for existing render: mineral, silicate-bound or silicone-bound render calls for a siloxane paint; acrylic-bound render calls for acrylic again. During the site visit we establish which type your render is — mineral render visibly darkens when you wet it, resin-bound render does not.
Anyone who saves on preparation saves on the one stage that determines how long the result lasts. This is what happens before any paint is involved.
If your facade still looks good but the rain is driving through it, painting is not the only route. A water-repellent treatment makes the masonry shed water without laying a film over it, so that vapour permeability remains virtually untouched and your brickwork stays visible.
Conditions: brick and joint in good condition, no cracks, no rising damp, and sound connections. It makes sense against direct driving rain, not against other causes of damp. We propose it where it fits — even though it is a smaller job than painting.
If you have ended up in the second list, the render needs renewing. At that moment you pay for the scaffolding, the preparation and the complete finish all over again. That is precisely the moment to do the sums: add external wall insulation and you go from roughly €40 to €80 per m² to €110 to €150, and you keep 30 to 35% of your heating costs in your pocket from then on.
We would rather say that now than after you have paid for scaffolding a second time. If you want to weigh that choice up at your leisure, it is set out in full on choosing insulation.
If you have an insulated facade that is ready for a refresh after ten or fifteen years, nothing has to be taken down. Repainting is possible — within two limits.
The paint must be vapour-open and approved by the supplier of your ETICS system. A different product voids the system warranty — and you only find that out when you need it. On top of that, a paint on ETICS must be water-beading and dirt-repellent, to limit the water absorption of the decorative render and the effect of UV.
The Belgian ETICS Manual holds that the lightness value of the colour must be higher than 20%. That limit does not disappear when you repaint: the finishing layer on insulation stays a few millimetres thick, and EPS starts to deform above 80 °C — a temperature that a dark facade reaches in summer sun. More on that on the render and decorative plaster page.
Work out your indicative price online. During the free on-site visit we establish the type of substrate and tell you honestly which of the two you need — even when that is the smaller job.
VediWorks is one of Vedi Group's four companies. Interior painting, a post-construction clean or maintaining shared areas: one contact, the same crews, the same standard.
