We don't compromise on any stage of the painting process. Our contractors are divided into two specialised teams - groundworkers and painters - which ensures that each stage of the work is carried out with care and a long-lasting result.
Primer work and its technical importance - Why is the durability of the paint surface determined before painting?
A quality facade painting is the result of a combination of the right paint product, suitable weather conditions and professional application techniques. However, the single most important factor in the lifetime of a painted surface is the technical quality of the substrate.
Each of the Pensla priming steps and their technical impact on adhesion, moisture control and long-term durability of the paint surface are detailed below.
1. Mechanical removal of old, poorly adhered paint
Technical importance
The bearing capacity of the adhesive surface:
The adhesion of the paint is based on the fact that the substrate is load-bearing. A loose or poorly adhered paint cannot withstand the weight, thermal movement or moisture absorption of a new paint film.Eliminating tensions:
Peeling of the old paint layer causes shear stresses that are transferred directly to the topcoat → cracking of the new layer.Continuity of membrane formation:
The paint will only form a durable film on a flat, intact surface. An uneven, flaky surface will prevent the film from being uniform.Moisture management:
Loose paint flaps collect moisture → risk of microbial and rot damage and bubbling.
Without this step
Paint will start to peel off within 1-3 years
Infection does not meet the requirements of paint manufacturers
2. Washing surfaces thoroughly
Technical importance
The anti-infective substances are removed:
Dirt, grease, pollen, soot and microbes on surfaces prevent mechanical and chemical adhesion of the paint.Contaminants affecting capillarity:
Dust and organic matter can absorb and retain water → the paint cannot be absorbed, causing intra-membrane stresses.Microbial growth control:
Mould and algae damage the durability of the paint surface and can grow through the new paint film.Smoothing the moisture distribution of the surface:
Uniform absorbency is a prerequisite for uniform drying and curing of the film.
Without this step
The goal only partially sticks → scoring
The paint surface gets dirty very quickly
Moisture pockets form in the film → bubbling and peeling
3. Replacement of damaged exterior cladding panels
Technical importance
Structural moisture management:
Cracked or decayed wood absorbs moisture and the topcoat cannot fully prevent diffusion. Moisture breaks through the paint film, breaking it.Firmness of the bond base:
The wood cell is no longer load-bearing, so the paint cannot adhere with sufficient tensile strength.Managing life movements:
Damaged wood will live more with moisture → the paint cannot withstand large expansion and contraction movements.Capillary dehumidification:
Decayed wood absorbs more water by capillary action, reducing the technical life of the paint film.
Without this step
The paint surface cracks and peels right where the wood is technically weak
Structural layers can get wet and damage can increase every year
4. Roughing up the old paint surface
If the old paint is too hard, the surface should be roughened before applying a new coat. For example, old oil-based paints often need to be roughened.
Technical importance
Creating a mechanical infection:
The paint adheres in two ways: chemically and mechanically. An old hard paint film will not provide a mechanical adhesion surface without roughening.Opening up the microstructure of the surface:
Roughening creates a surface of microcracks to which the new paint “locks”.Removing surface gloss:
Glossy surface repels paint and causes flaking → uneven film.Equalising tensions:
The stresses of the new paint film must be transferred evenly to the substrate. Too smooth a surface will cause internal tensile stresses in the film → cracking.
Without this step
The topcoat is not absorbed but remains on the film
Paint film can peel off in large sheets within a few years
Adhesion strength below manufacturers' minimum requirements
5. Priming and undercoating of wooden surfaces
Technical importance
Managing the hygroscopicity of wood:
Bare wood absorbs moisture strongly. The primer seals the surface of the wood and slows down the movement of moisture.Capillary break:
The primer reduces the capillary rise of water in the wood, which would otherwise break the paint film.Creating an adhesive surface for the topcoat:
The primer forms a chemically compatible base for the topcoat (same manufacturer).Equalisation of absorption capacity:
The even absorbency prevents a “blotchy” finish and ensures an even film.Adding microbial protection:
Many primers contain fungicides that prevent rot and mould.
Without this step
The topcoat is absorbed unevenly and dries too quickly → the film does not have time to form properly
Wood surface gets wet by rain and dries in the sun → strong living movement breaks the film
The paint surface loses gloss, protection and durability from the first year onwards
Summary: Durability of the paint surface = technical quality of the groundwork
Each stage of the groundwork affects the following:
✔ Adhesion strength
✔ Capillary moisture control
✔ Right level of diffusivity
✔ Wood living management
✔ Paint film uniformity and stress levelling
✔ Microbial and mould resistance
✔ UV protection and weather resistance
When you make a mistake in the groundwork, the topcoat doesn't perform technically correctly - and its lifespan can drop from 10-15 years to just 3-5 years.
At Pensla, priming work is always carried out using technically correct methods to ensure that the paint surface can perform as intended by the manufacturer throughout its lifetime.