Good preparation makes or breaks a plaster job. You can hire the best plasterer in town; if the substrate is not treated properly, you will never get an optimal result. Below we explain why voorstrijk stucwerk matters, which products suit which substrate, and how Nourklusbedrijf builds a stable base for every plaster project.
Why priming is essential
Every wall absorbs moisture to some degree. If you start plastering without primer, the water in the plaster is often sucked straight into the surface. Drying becomes uneven, adhesion suffers and hairline cracks are more likely. A suitable primer regulates suction, so the plaster bonds properly, cures evenly and stays tight to the wall. That one step up front prevents a lot of trouble later. A common mistake is to plaster new masonry or concrete with no pretreatment. The result can be stains, flaking spots, colour variation or even sections that detach. With highly absorbent materials like calcium-silicate brick and gypsum blocks, that risk is high. On smooth, low-suction concrete the opposite happens: the plaster simply does not grip. A dedicated primer turns an unreliable surface into a dependable base.
Which product fits which substrate
Different materials, different needs.
- Concrete is smooth and low-suction. Use a bonding primer with a fine aggregate so the plaster has something to bite into.
- Gypsum blocks are very absorbent. Choose a suction-regulating primer to stop the plaster water disappearing too fast.
- Calcium-silicate (sand-lime) brick benefits from a deep-penetrating primer that evens out suction through the full face.
At Nourklusbedrijf we identify the substrate first, then select the product. That is how we make sure the primer and the plaster system are actually compatible.
How to apply primer correctly
Start with a surface that is clean, dry and dust-free. Apply the primer evenly with a roller or block brush. Do not flood the wall; a thin, uniform coat is what you want. Drying times vary by product, typically between four and twenty-four hours. Beginning to plaster too soon compromises adhesion. A simple check helps: run your hand over the surface. If it still feels tacky, wait. Using the wrong product on the wrong wall looks harmless but often leads to poor bonding, staining or even mould behind the finish. We also see primers rolled on far too thick, or work resumed before the coating has dried. Good priming is not about speed; it is about judgement. Our crews know what each surface needs and take responsibility for that decision.
Primer vs contact primer: what is the difference
A primer/sealer is designed to regulate suction. A contact primer creates mechanical grip on smooth, low-suction surfaces. You will not use the same pretreatment on gypsum as on concrete. If you do, the plaster may let go on one of the two. That is why we assess each wall and specify accordingly, rather than throwing a one-size-fits-all product at it.
Can you use too much primer
Yes. Too much product can seal the wall like a plastic film. In that case the plaster bonds worse, not better. The fix is simple: apply a thin, even coat and follow the manufacturer’s coverage and drying guidance. On our jobs we tune the application to the wall type and the project schedule, so the plaster goes on at the right moment.
“What if I skip it altogether”
The damage is not always obvious on day one. After painting or with temperature swings, you may see cracking, blisters or areas that lift. We would rather spend five extra minutes up front on proper priming than hours on repairs later. The difference lives in the details, and that is where we stay sharp.
Why work with Nourklusbedrijf
We believe quality starts before the first trowel hits the wall. We look at the substrate, the site conditions and the planned finish, then set the right sequence. Our teams use professional-grade products and make sure each wall gets the pretreatment it needs. The payoff is simple: a finish that is straight, strong and built to last.
How seasons affect priming
Weather matters. Our specialists adjust on site, with ventilation, gentle heat or shade where needed. The aim is consistent quality, regardless of the month.
Renovation vs new build
Renovations often reveal old paint, cement residues or damp patches. Prep is heavier there: sometimes walls must be cleaned or abraded before primer can even do its job. In new build, substrates are usually flat but extremely absorbent, so the correct primer is just as important. In both cases the final quality rises or falls with a thoughtful approach to the base.
For personal advice and a plan that fits your project, contact Nourklusbedrijf.
Source: Primer for plaster on concrete, gypsum or calcium-silicate brick
