Top 5 mistakes of wet facade insulation

A wet facade system is a well-liked and practical option for insulation in homes. This technique not only makes your building look better overall, but it also makes it more energy efficient. Nevertheless, despite all of its advantages, a lot of homeowners and even experts make frequent mistakes that can reduce the insulation’s effectiveness and longevity.

Comprehending these errors is essential to guaranteeing that your insulation endeavor yields the intended outcomes. These mistakes, which can range from poor material selection to poor installation methods, can result in expensive repairs and decreased insulation efficacy. You can proactively avoid these pitfalls by being aware of them.

We’ll look at the top five mistakes that are frequently made when insulating wet facades in this article. This guide will assist you in creating an insulation system that is more dependable and effective, regardless of whether you are starting a new project or trying to enhance an old one. Let’s examine these typical mistakes and discover how to avoid them for an effective and long-lasting insulation solution.

1. Wrong choice of thermal insulation thickness

Thermal engineering calculations should be used to determine the thickness of the insulation for wet insulation of facades. It is crucial that the external wall’s heat transfer resistance (R-value) does not fall below accepted norms. Minimum temperatures in Ukraine’s zone 1 are R = 3.3 m2K/W, while zone 2 has R = 2.8 m2K/W.

For external wall insulation, the typical thickness of thermal insulation is 10–15 cm, occasionally 20 cm, depending on the kind and thickness of the wall material. The "dew point," or the part of the building where the temperature is the same as the water vapor condensation point, is guaranteed to move from the wall to the thermal insulation layer due to the thickness of the insulation. This will ensure that the wall is consistently shielded from moisture and freezing. Inadequately thick thermal insulation will not offer adequate thermal protection and will raise the cost of heating the home. Furthermore, this will eventually have a detrimental effect on the wall’s structural qualities.

However, you should be aware that a layer of thermal insulation that is too thick (greater than 20 cm) may detract from the house’s appearance. Less light will reach the windows because they will be set back into the facade due to the thick layer of insulation.

2. Selection of materials without taking into account vapor permeability requirements

Mineral wool or polystyrene foam are the two most common insulation materials used for wet facade insulation. Conversely, mineral wool permits air and water vapor to pass through freely, whereas foam plastic virtually prevents them from doing so.

Condensate can be drained from the insulation thanks to the arrangement of the mineral wool façade, which has layers of vapor permeability that increase from the inside to the outside. If the free flow of steam through the mineral wool is not ensured, the insulation will become wet and lose its ability to retain heat, causing the wall to freeze and the growth of mold and mildew.

This relates first and foremost to the selection of plasters and finishing paints. Nearly any exterior finish can be used with foam plastic systems; however, only vapor-permeable silicate, mineral, silicone, and plasters are used when using mineral wool; acrylic mixtures, which act as a vapor barrier, are not used.

Moreover, it is preferable to avoid using foam plastic for any kind of insulation on walls made of high vapor permeability materials, such as aerated concrete, silicate brick, and concrete, and foundation structures.

3. Saving on glue and other components

Kits or separate components can be purchased to complete a facade’s wet insulation. The adhesive mixture for attaching thermal insulation, plaster, reinforcing mesh, insulation, and dowels for attaching insulation are all included in any set.

Some craftsmen, when choosing their own parts, feel that the insulation can be fastened with dowels instead of glue to the wall. In other situations, they advise skipping the glue altogether or substituting a low-cost option (like tile adhesive) for the adhesive mixture used for insulation.

However, a wall with this level of insulation will probably start to crumble. There will be plaster cracks, thermal insulation that peels and tears, etc. Facade external insulation is a lengthy process, so it is best to avoid making financial cuts, reducing the glue’s amount, or diluting it with sand.

An additional issue pertains to the inappropriate selection of dowels for facade systems, which need to endure the associated loads, variations in temperature and humidity, impact from the outside world, etc. The type, thickness, and material of the wall should all influence the fastener selection. Simultaneously, dowel quantity and quality play an important role in fixing thermal insulation.

For long-lasting results, it is imperative to avoid common mistakes when insulating a building using a wet facade system. The top five mistakes include inadequate finishing techniques, utilizing low-quality materials, applying insulating layers incorrectly, failing to use reinforcement mesh, and performing improper surface preparation. Each of these errors can reduce the insulation’s efficiency, which can result in energy loss, moisture issues, and a facade that is less durable. Homeowners and builders can guarantee a more effective and long-lasting insulation job, ultimately saving time and money, by being aware of and avoiding these pitfalls.

4. Incorrect installation of insulation

The most frequent mistakes in fastening elements should be avoided when installing a wet facade insulation system. First among them is the loose joining of insulating boards and the use of glue to seal the joints. This causes the finish coating to crack and form cold bridges in both situations. Strips of thermal insulation material must therefore be used to fill any gaps larger than 2 mm when installing thermal insulation slabs.

Creating a monolithic thermal insulation contour all the way around the house is crucial. The most challenging areas are observed closely, including corners, niches, protrusions, and openings. Here, the components must be connected to the wall with elastic to prevent moisture infiltration.

It’s crucial to align the dowel caps with the thermal insulation layer’s exterior when installing insulation. If not, the finishing plaster will develop lumps or depressions, which will exacerbate the system’s structural flaws.

A wet facade insulation project’s likelihood of success is mostly dependent on avoiding common pitfalls. You can create an effective and long-lasting insulation layer by using appropriate application techniques, surface preparation, and material quality.

Choosing premium materials is one of the most important steps. Taking short cuts here could have serious consequences later on, like decreased insulation effectiveness and possible structural damage to the building. Always select goods from reliable producers, and pay close attention to their instructions.

Another important component is surface preparation. Gaps and thermal bridges could result from improper insulation adhesion in the absence of a dry, clean, and stable base. Prior to beginning the insulation process, give the surface a thorough cleaning and priming.

Appropriate application methods carry equal significance. Make sure you mix and apply the insulation materials according to the manufacturer’s instructions. The effectiveness and longevity of the insulation are compromised by uneven coverage that can arise from inconsistent application.

Lastly, never undervalue the significance of continuous maintenance. Minor problems can be kept from growing into major problems by doing routine inspections and making timely repairs. You can make sure that your wet facade insulation keeps working effectively for many years by being watchful.

You can guarantee a successful wet facade insulation project that offers superior thermal performance, improves the building’s aesthetic appeal, and adds to its overall durability and energy efficiency by avoiding these top five mistakes.

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