The most common mistakes in decorative plastering – what to avoid?
Decorative plasters, especially those applied by spraying, enjoy unflagging popularity both in residential construction and in commercial projects. It is no wonder – they allow for original textures such as “lamb” or “bark beetle” effect, increase the resistance of facades and interior walls to damage, and at the same time enable fast work progress. However, the final result, which can delight for many years, can be very easily ruined already at the application stage. Many people, both amateurs and experienced contractors, unknowingly make basic mistakes. Their consequences can be costly – from adhesion problems, through unsightly streaks and discoloration, to the need to completely remove the plaster.
So let us take a step-by-step look at where the most common mistakes occur and how to effectively avoid them.
Introduction – the popularity of decorative plasters
Spray and decorative plasters have gained recognition primarily due to their aesthetics and functionality. Thanks to a wide range of colors, structures and mechanical properties, they make it possible to create durable surfaces resistant to changing weather conditions. They are used both on building facades and in modern interiors, where they emphasize the character of the space. Despite advanced technologies, these plasters still require a diligent approach – they do not forgive neglect.
Lack of proper substrate preparation
The vast majority of plastering problems originate even before application begins. Improperly prepared substrate is one of the fundamental mistakes, resulting in poor adhesion of the plaster mass and its rapid detachment. A common occurrence is applying plaster on an uncleaned, dusty or greasy surface. Seemingly minor contaminants – dust, paint residues, traces of cement plaster – can significantly reduce adhesion, which manifests after a few weeks as cracks or peeling patches.
Another oversight is skipping priming. Primer, although often treated lightly, plays a key role: it strengthens the substrate, evens out absorbency and improves the bond of plaster with the load-bearing layer. Omitting it poses not only aesthetic but also structural risks. The same goes for surfaces that are not fully dried – moist substrate creates ideal conditions for air bubbles and plaster detachment.
Too high or too low humidity
Humidity – both of the air and of the surface itself – is a key factor affecting the plastering process. Excessive substrate moisture prevents the mix from properly bonding with the wall. Already during application, the first signs of detachment may appear, and in extreme cases the plaster may “slide” down the wall.
This problem often affects newly erected buildings, where the walls have not had time to dry properly. On the other hand, too low humidity and high temperature lead to overly rapid evaporation of water from the mix, which prevents proper bonding and results in dull spots, air bubbles and discoloration. In any situation, it is worth using a moisture meter to avoid guessing and act based on specific data.
Application in unfavorable weather conditions
Weather conditions directly affect plastering quality – especially when work is performed outdoors. Excessive sunlight can cause the outer layer of plaster to dry too quickly while the interior remains moist. This results not only in an unsightly appearance but also in serious structural damage.
Wind, in turn, can “blow away” plaster particles, making the applied layer uneven and full of gaps. Rain or high humidity in the air after plastering may wash out the binder, resulting in a weakened protective layer. The ideal temperature for applying decorative plasters is between 10 and 25°C, with relative humidity not exceeding 70%.
Improper spraying or troweling technique
Although spray plasters allow for fast application, they require great precision and skill. Too fast nozzle movement or inconsistent strokes may lead to an uneven texture. Lack of control over the distance from the wall results in “overshot” fragments that are later difficult to even out.
Errors also occur at the troweling stage. Many contractors unnecessarily rush this step or use inappropriate tools. As a result, the achieved “lamb” or “bark beetle” effect is chaotic and irregular, and the surface inconsistent in texture and light reflection. Troweling should be performed right after the plaster slightly dries – when it is no longer sticky but still plastic.
Mistakes in mix proportions or using wrong materials
Decorative plasters, especially those sold as dry mixes, require precise dosing of water. Even small deviations from the recommended proportions may change the consistency and working parameters. Too thin a mix does not stay on the wall, runs down and creates streaks, while too thick is difficult to spread and dries faster, limiting working time.
A frequent mistake is also mixing materials from different manufacturers or combining leftovers from several buckets. Although they may look similar at first glance, their technical parameters may differ, leading to unpredictable chemical reactions, reduced durability and uneven color.
Lack of corner profiles and protections
Aesthetic and durable finishing of corners, window edges or wall joints is not only a matter of precision but also proper preparation. Skipping protective profiles is asking for trouble. Without them, wall corners are exposed to quick mechanical damage, and plaster edges easily crumble and peel.
Another problem is the lack of protection in sensitive areas such as joints with windowsills or windows. Negligence in these places most often results in water seepage, cracks and the need for local repairs after the first winter season.
Finishing too quickly – not allowing drying time
Time is money – this rule often leads to mistakes made out of haste. Decorative plaster, regardless of type, needs time to dry naturally. Accelerating this process, e.g. with heaters or forcing work in unfavorable conditions, results in improper bonding of ingredients. The coating becomes brittle, and microcracks appear after just a few days.
Special attention should be paid to colored plasters – too rapid drying leads to streaks and uneven color, which often requires repainting the entire surface.
How to avoid these mistakes?
Awareness of risk is the first step toward eliminating it. Following the basic rules, such as priming, controlling humidity and temperature, following the manufacturer’s recommendations and maintaining patience throughout the process, significantly increases the chances of achieving a durable and aesthetic result.
Precision and knowledge are the keys to success
Applying spray and decorative plasters is a process that – although at first glance may seem uncomplicated – requires knowledge, experience and great attention to detail. It is precisely the details that determine whether the final effect will be durable and aesthetic, or full of imperfections that will quickly become apparent. The mistakes we have discussed are repetitive and common – but that is good news, because it means they can be effectively avoided if one knows what to look out for.
At Murrami we perfectly understand that not everyone has to be an expert to create beautiful, professional-looking surfaces. That is why with each of our products – whether spray, structural, silicone or decorative plaster – we provide materials that show step by step how to apply them correctly. Without marketing jargon – we show real applications, real walls and specific techniques. We explain how to avoid the most common mistakes and how to deal with more challenging conditions.
If you are just starting your journey with plasters or simply want to be sure that the result will meet your expectations – check our instructions, guides and videos. You will find them on each product page. Our knowledge is there so that you can calmly focus on the work and achieve a result that truly impresses.
At Murrami we do not just sell materials – we show how to use them wisely. Check us out and see for yourself.