How to plaster walls from foam blocks inside and outside the house correctly

The durability and appearance of your home can be greatly improved by plastering walls composed of foam blocks. To guarantee a smooth and durable finish, whether working on interior or exterior surfaces, the procedure calls for meticulous planning and the appropriate tools. Due to their superior insulation qualities and ease of use, foam blocks are a common building material; however, they do pose some particular plastering challenges.

A well-applied plaster layer enhances the aesthetics of interior walls and offers a sturdy surface for painting or wallpapering. Selecting the right plaster materials and properly preparing the surface are essential for a successful plaster job on foam blocks inside your house. Plaster adheres more readily to surfaces that have been properly prepared, which lowers the possibility of cracks and other problems later on.

Plastering external walls has the dual benefit of improving the curb appeal of the home and shielding the foam blocks from the weather. For external plaster to endure elements like wind, rain, and temperature changes, it must be more resilient. Your external walls will stay beautiful and safe for many years to come if you use the proper plaster and apply it properly.

We’ll take you through all the necessary procedures for plastering foam block walls inside and outside your home in this guide. From material selection and surface preparation to plaster application and finishing touches, our goal is to provide you useful advice and insights to help you accomplish expert results. Whether you are an experienced do-it-yourselfer or a novice, you can approach your plastering project with confidence and ease if you follow these tips.

What is a foam block and why do you need its internal plaster and facade

One type of building material that is used to make internal or external partitions is foam block. Concrete, sand, water, and foaming agents are combined to make it.

To preserve the building material, foam blocks are plastered onto walls both inside and outside the home. The blocks will progressively take up carbon dioxide from the air if they are left open. As a result, the process of destroying them is started. If foam concrete isn’t plastered over, shrinkage due to carbonization will happen quickly.

Block volume decreases and chalk formation are characteristics of this process. Building materials experience a reduction in their service life due to rapid carbonation shrinkage. Foam block plastering is regarded as a cost-effective and reasonably priced wall finishing solution.

What is the best way to plaster a foam block

Choose the right mixture for the base before plastering the foam blocks. Think about the location (street or room) where the work is going to be done. The performance qualities of the base will be diminished by an incorrect choice of finishing material.

• for rough work;
• specialized (soundproofing, barite, waterproofing, noise-suppressing);
• decorative.

.. a pricey item with strong performance characteristics. Elastic and long-lasting is silicone plaster. Although it is vapor-permeable, it repels moisture.

Inside the house

Plaster is chosen for interior decoration based on the room that will receive the repair. Waterproof compounds should be used first if the foam block wall will be exposed to high humidity.

• cement or cement-polymer;
• silicone;
• acrylic.

Gypsum mixtures can be used in rooms with low humidity levels. A room’s fire hazard is considered when designing the interior, in addition to humidity.

Consequently, not all combinations are suitable for finishing spaces that have a fireplace, for instance. Refusing acrylic plaster is preferable if there is a fire source in the space.

Outside the house

For external foam blocks, the plaster needs to be stronger. The finishing material must be resistant to temperature fluctuations and UV radiation in order to last for a long time.

There are several options available when selecting plaster for a building’s facade: silicate, cement (cement-lime), silicone, or acrylic mixture.

Necessary tools and materials for plastering foam blocks indoors and outdoors

You must get all the tools needed for the task ready before plastering a foam block wall. It is not advisable to get sidetracked while finishing by looking for missing pieces. Ignoring this rule could ruin the mixture, for example, if it sets quickly, in addition to the wall’s appearance.

• primer;
• adhesive composition (when creating a wet facade);
• corners;
• rule;
• sandpaper;
• level;
• spatula;
• trowel;
• grater;
• construction mixer (for mixing the mixture);
• roller.

In the event that a dry mixture was bought and needs to be separately prepared (add water) before use, a second mixing container will be needed. Plasters that are premade are used right away after being opened. However, it is preferable to prepare an additional container if the one in which they are released is large and cannot be used up quickly. It is filled with a tiny portion of the finishing mixture before being applied to the wall. This division technique will shield the completed plaster from damage and early hardening.

Gloves and safety glasses must be worn when working to prevent health risks. When mixing the bulk mixture and getting the walls ready for finishing, a respirator is needed.

Preparing the surface for plastering with cement mortar

A foam block wall needs to be properly prepared before plastering. It is imperative to apply preliminary surface treatment in order to enhance adhesion and prolong service life.

The wall’s cables, if any, are de-energized. Even though the cables are insulated, there shouldn’t be any electricity at the work site.

The work area’s cracks must all be widened before being sealed. Everything that protrudes or is driven into the wall, such as screws and nails, is taken out. Metal components should not be left unattended as they are prone to corrosion. Rust will eventually show up on the exterior.

All wall pieces that don’t hold together well (chipped elements) must be removed. Cracks and voids are filled after cleaning. You can use plaster or cement mortar at this point.

If there are protrusions on an uneven wall surface, they should be ground off or removed. Using specialized compounds, traces of mold, oily stains, rust, etc. are eliminated. Sandpapering the walls is required to increase the base and coating’s adherence. Dust the work surface to complete the preparation process.

How to properly plaster walls made of foam blocks outside or inside the premises with your own hands

The degree of freezing must be considered when decorating an apartment’s walls or a box made of foam blocks that are exposed to the elements (i.e., not inside partitions). Making the plaster from the street two times thicker than the room’s is advised to prevent the appearance of moisture, mold, and other potential bad effects brought on by temperature fluctuations.

Use of primer

Foam blocks are primed before being plastered on interior walls or outside walls. Experts advise applying compounds with deep penetration. A roller is used to apply the primer. The wall is coated from the bottom up to lessen splashing and the amount of streaks. It is necessary to wait until the work surface is completely dry before applying the second layer. Ignoring this will cause the primer to roll off. In two or three layers, the wall is processed last.

Fastening the plaster mesh

A mesh is used to increase the finishing material’s adherence to the working surface. Fiberglass products should be preferred because they don’t corrode. However, metal mesh is also present.

Plaster is used for fastening. Using a spatula, apply a thin layer (no more than 7 mm) to the wall. The base is covered with mesh that is recessed. Smooth from the center to the edges with a spatula.

Make sure the entire mesh is submerged in the solution. Plaster can be applied over the canvas if there is insufficient of it. Mesh joints have a five-centimeter overlap.

Is it necessary to install beacons?

Beacons are fastened to the wall prior to plastering the foam blocks outside (or inside). When it is required to level the wall and when the applied layer has a thickness greater than 5-7 mm, elements are installed. Plastic or metal can be used to make beacons. Plaster sheets can have the guides fastened to them. The distance between any two strips shouldn’t be greater than the rule’s length.

You can use a rope to verify that beacons are placed correctly in the absence of a building level. It is drawn in between the leading and trailing planks. The thread will be at the same level (with respect to the beacons) if the work is done correctly.

Beacons are also found at corners. They align, provide stiffness to the slope, and facilitate the uniform application of the solution.

Laying plaster in several layers

Plastering in a single layer is done on surfaces that are reasonably smooth. Finishing material is laid layer by layer if the wall has a significant curvature. For every layer, a different batch of the solution is made to prevent wasting it.

Water is sprayed onto the foam block surface that is ready for finishing. The following step involves creating a semi-liquid solution. Using a trowel, the resultant mass is placed onto the wall and leveled. The spray should have a thickness of roughly 5 mm.

The primary layer comes next. If a dry mixture was purchased, plaster is ready for it as per the directions on the package. Using a spatula, the finishing material is applied to the wall, and a rule is used to smooth it out in accordance with the beacons’ level.

A liquid mixture comprising a sizable filler is used to create the grouting, or final layer.

Grouting

The final layer of plaster needs to be processed when it partially dries but no longer sticks to the touch. You’ll need a float with rounded edges for this. Using a tool like this will help prevent scratches.

After applying the float to the work surface, circular motions begin. There ought to be minimal force applied. Hard pressure applied to the float will cause the plaster’s surface to distort. Milk will start to separate from the wall as you work. It will cover minor voids in the plaster. Using a napkin, remove any extra milk from the float.

Use the "running" technique to complete the grouting. After applying the float to the wall, swiftly execute rectilinear movements in both the horizontal and vertical directions (alternately).

Popular manufacturers of plaster mixes

• Polimin;
• Knauf;
• Ceresit;
• Osnovit;
• Baumit;
• Atlas;
• Perfecta, etc.

Foam block plastering demands precise planning and application of the proper techniques to guarantee a smooth and long-lasting finish. It’s crucial to properly clean the blocks, use the right plaster mix, and apply a suitable primer whether working on interior or exterior surfaces. In addition to improving the aesthetics of your house, properly plastered foam block walls offer increased insulation and moisture resistance. This guide will take you step-by-step through the entire process, providing expert advice and useful tips to help you produce results that look professional.

Nuances of plastering on foam blocks from the inside and outside

The outcome of the work is dependent on more than just the finishing material application skill.

1. It is recommended to start finishing a month after the construction of the walls. It takes time for the blocks to shrink. If you do not wait, cracks will appear on the surface.
2. When working with plaster mixes, it is necessary to adhere to the temperature regime. Finishing is not carried out if the parameter does not fall within the range of +5 ° C … + 30 ° C. The indicator may differ slightly for different mixes. The manufacturer indicates the operating temperature on the packaging of each product.
3. Bulk mixes must be prepared according to the manufacturer"s instructions. Mix the solution before use.
4. Before plastering foam blocks indoors, make sure there are no drafts.
5. You cannot speed up the plaster drying process with auxiliary devices (heaters, fans).
6. When multi-layer plastering, each subsequent layer is applied after the previous one has completely dried.

Step	Details
1. Clean the Surface	Remove dust, dirt, and debris from the foam blocks.
2. Apply Primer	Use a suitable primer to improve plaster adhesion.
3. Mix Plaster	Prepare plaster according to manufacturer"s instructions.
4. Apply Base Coat	Spread a thin layer of plaster evenly on the wall.
5. Level the Surface	Use a straight edge to smooth and level the plaster.
6. Apply Finish Coat	Once the base coat is dry, apply the final layer of plaster.
7. Smooth the Finish	Use a trowel to create a smooth surface.
8. Allow to Dry	Let the plaster dry completely before painting or decorating.

Both inside and outside of your home, plastering foam block walls can greatly enhance the look and longevity of your building. Careful plaster application and meticulous preparation are essential for a successful plastering project. You can get a smooth, durable finish that shields your walls from the weather and normal wear and tear by following the right procedures.

Make sure the foam block surface is dry, clean, and devoid of any loose materials before starting. A primer or bonding agent is applied to the foam blocks to improve plaster adhesion. Using a weather-resistant primer is particularly crucial for exterior walls to stop moisture seeping in.

It’s important to mix the plaster with the proper consistency. If it’s too thick, it will be difficult to apply smoothly; if it’s too thin, it won’t offer enough durability or coverage. Thin, even layers of plaster should be applied; let each layer dry fully before applying the next. This method guarantees a stable, uniform finish and keeps cracks from occurring.

Consider utilizing a reinforcing mesh for exterior plastering to increase strength and stop weather- and temperature-related cracks. After the plaster has dried, careful troweling and sanding can produce a smoother finish inside.

It is imperative that the plaster cures properly. For the plastered surface to set slowly and gain maximum strength, keep it moist for a few days. This stage is especially crucial for external walls that are exposed to wind or direct sunlight, as these conditions can cause the plaster to dry out too quickly and fracture.

You can give your foam block walls a finish that looks professional by taking the time to properly mix the plaster, prepare the surface, and apply it in thin, even layers. These guidelines will help guarantee that your plastering project is both elegant and long-lasting, enhancing the value of your house whether you’re working indoors or outdoors.

Video on the topic

How to plaster walls made of foam blocks

A simple, economical way to plaster foam blocks

How to plaster walls made of foam blocks inside. (foam concrete, aerated concrete, gypsum plaster)

Plastering and puttying aerated concrete WE BUILD FOR OURSELVES

Plastering aerated concrete, preparing the base