How and what is the best way to insulate a house made of cinder blocks: methods and choice of materials

In order to keep the interior of a cinder block home comfortable and to save energy expenses, insulation is necessary. Although they are strong and reasonably priced, cinder blocks are not well-known for their insulating qualities. For this reason, selecting the appropriate insulation technique and materials is essential to improving your home’s thermal efficiency.

There are various techniques available for insulating cinder block homes, each with pros and cons of their own. The most widely used methods are filling the hollow cores of the blocks and insulating the exterior and interior of the blocks. Every approach has different advantages and difficulties based on things like climate, spending capacity, and the house’s current structure.

There are many options available to homeowners when choosing insulation materials. Mineral wool, fiberglass batts, rigid foam boards, and spray foam are common options. The degrees of moisture resistance, heat resistance, and installation ease vary amongst materials. Your unique requirements, such as whether you value fire safety, energy efficiency, or simplicity of installation, will determine which option is best.

The comfort and energy usage of your cinder block home can be greatly affected by knowing how to insulate it. You can choose an approach and material that best fits your needs for insulation while staying within your budget by researching various options. This guide will show you how to insulate your cinder block house in the most efficient ways possible, making your home cozier and more energy-efficient.

Why is wall insulation necessary?

For load-bearing cinder block walls, a minimum thickness requirement is 20–25 cm.

It is no longer enough to keep the interior of the building at the ideal temperature when the cold weather arrives.

The only method left to keep costs as low as possible is to use thermal insulation since thickening the walls is not a financially viable option.

Furthermore, thicker walls detract from the building’s overall appearance.

Installing insulation has the following benefits:

• Allows you to maintain an acceptable wall thickness, so that enough light enters the house.
• Thermal insulation on top of the building can be covered with facing material, which will visually decorate the structure.
• Heating costs are reduced and the house remains at normal temperature longer.
• In summer, the walls do not let out coolness, it is pleasant to be in the rooms, there is no heat and unbearable heat.
• Increases the service life of the building. Cold air increases the humidity on the walls of the building, gradually the building material collapses and cracks appear. If the house is warm, the cinder block remains dry and unharmed for as long as possible.

Crucial! Because of the harsh winters and high humidity in the northern and central regions of Russia, insulation installation is required.

What are the dangers of lack of thermal insulation??

Some building owners think that cinder blocks don’t require insulation because they contain sawdust and expanded clay. However, the following consequences for the structure will occur if this is not done:

• Cold walls and floor. This is especially true in windy regions where winters are frosty. Heat loss directly affects room heating. Building maintenance costs will increase. In addition, it will simply be uncomfortable to be inside; the cold floor is dangerous to the health of the residents.
• Increase in humidity. During periods of frost, condensation will appear on the walls, which will accumulate in small puddles and wash away the building material. Despite the fact that cinder block is not a favorable environment for the growth of mold or mildew, finishing materials are not. There is a high probability of the appearance of microorganisms, which is dangerous for people.
• Moisture penetration destroys the cement in cinder blocks. The building material collapses, gradually crumbles, cracks appear. The result may be the destruction of the wall.
• There is a danger for finishing materials inside the house, many of which are not designed to withstand temperature changes and can burst (glass, plastic), collapse, deteriorate.

An insulated cinder block building can prevent the need for repeated repairs or irreversible damage to its walls.

When you need it outside and inside, and when only on one side?

To ensure that the house warms up uniformly and doesn’t leak warm air, insulation must be added to the outside or inside of the wall.

There are only two ways to insulate cinder block walls: either on the outside only or on both sides.

It is common practice to install insulation on a building’s exterior to regulate temperature and preserve building materials. The laws of physics state that cold air will travel through finishing material and an insulation layer before reaching the cinder block. Condensation won’t build up on the walls because of the external covering of the house acting as a filter.

Benefits of cinder block insulation outside the structure:

• finishing materials will create a barrier and protect the blocks;
• usable space inside the house is preserved;
• the wall becomes a kind of battery, the ability to retain heat increases by 70%, and the ability to return it appears;
• eliminating the risk of fungus;
• the service life of the material increases, since it is not subject to freeze/defrost cycles;
• the dew point shifts, moisture evaporates from the finishing material;
• insulation and finishing protect the supporting structure from mechanical damage and precipitation.

Warm and cold air will mix and form a dew point when moving through bare cinder concrete if you only create a thermal insulation cushion inside the home. The insulation layer and interior décor will get wet, the walls will get covered in moisture, and the rotting process will start. This will cause the house to develop a wet wall, which will cause microorganisms to proliferate rapidly and disturb the room’s microclimate.

It is traditional to apply plaster and finishing material to the cinder block inside the building. Only in northern climates may insulation be required as an extra defense against the cold, which can trap heat.

For a cinder block home to be more comfortable and energy efficient, insulation is a must. The most effective techniques use spray foam for sealing cracks and gaps inside and rigid foam boards for creating a thermal barrier outside. Your budget and climate will determine which materials, such as expanded polystyrene (EPS) or extruded polystyrene (XPS), are best for you. Maximum effectiveness is ensured by proper installation, which lowers heat loss in the winter and keeps your house cool in the summer. You can greatly reduce your energy costs and improve your living space by properly insulating your cinder block home.

Pie with thermal insulation

The SNiP 23-02-2003 specifies that a cinder block’s wall should be between 15 and 20 cm thick. Its width allows for the maintenance of a pleasant living microclimate.

For the outside

What a correctly sized wall pie with insulation looks like:

1. Wall.
2. Adhesive adhesive composition on which the insulation is attached (if it is suitable for thermal insulation).
3. Insulation. Its thickness depends on the characteristics of the selected material. For northern regions, 10 cm is enough, for southern regions 5-7 cm.
4. Reinforced mesh.
5. Waterproofing. For it, a special waterproof film, membrane is selected.
6. Facing material. For external work, a material resistant to weather conditions is selected, for example, siding, clinker brick, or the house is covered with decorative plaster for painting.

For internal

Cinder block insulation is used both internally and externally. When installing thermal insulation outside the building is not an option, use this as a final resort.

Pie chart:

1. Wall.
2. Antifungal coating. Prevents the appearance of microorganisms.
3. Insulation. As a rule, it is laid in 1 layer 5 cm thick.
4. Vapor barrier. Thermal insulation from the inside is most often done for end walls and in the bathroom/steam room. The exhaust air must not condense on the wall. A layer of vapor barrier helps bring it back, keeping the house warm.
5. Facing material. Most often they choose dry fastening of plywood or plasterboard, which is then decorated as desired.

Crucial! In order to hold insulation that is layered, you will need to install profiles. To maintain a ventilation gap and guarantee a dependable connection, the layers are fastened together using disc dowels.

What insulation materials are suitable?

Both the building’s interior and exterior walls are insulated with the same materials. You must construct on its properties in order to determine which is best.

Polystyrene foam or polystyrene foam

The outside of the house is typically where this material is used. Has benefits:

• High thermal conductivity, this is the most effective insulation on the market. Its standard thickness of 10 cm is enough for thermal insulation of external walls.
• Hygroscopic, absorbs less than 4% moisture relative to its own volume. To protect it from moisture, you can use simple waterproofing, for example, film.
• High density. It withstands finishing with wet materials (plaster) well and is not afraid of mechanical damage.
• The surface is not susceptible to attack by microorganisms. This property does not depend on treatment with fungicides and is maintained until the end of its service life.
• The cost is affordable, the installation technology is simple.
• A light weight. Thanks to it, there is no additional pressure on the wall.

Drawbacks:

• Fire hazard. Simple material can easily catch fire.
• Over the years, styrene begins to release the toxin. Therefore, it is not recommended for internal insulation.
• Maximum protection from sunlight is required, they destroy its structure.
• Polystyrene foam is fragile and does not like solvents.

Experts in the field advise utilizing PSB S-25 polystyrene foam boards. The element measures 50 cm in width, 1 m in height, and 10 cm in thickness. Certain manufacturers incorporate fire-retardant materials into their products.

Mineral wool

The better kind of thermal insulation for interior design.

Benefits

• Flexibility. With its help, you can not be afraid of uneven surfaces and correct them for further finishing.
• Resistance to microorganisms.
• Fire safety. Not afraid of heat or temperature changes.
• Optimal vapor permeability, prevents the formation of condensation on the walls.
• Soundproofing properties.
• Environmental safety, absolutely natural material, does not emit toxic substances.

One drawback is its hygroscopicity. Cotton wool hates moisture; it stops working and starts to rot when it gets wet. Vigilant hydro and vapor barriers are necessary.

Wool made of basalt or stone is used for installation inside buildings. They operate without producing waste and have superior qualities. For walls, mineral wool P-125 and PZh-175 is advised due to its ideal rigidity and superior sound-absorbing qualities.

Sprayable solution

Both the inside and outside of the building can use this kind of insulation.

Benefits

• service life up to 10 years;
• simplicity and speed of application;
• no need for fastening material, applied directly to the wall and connected to it;
• creates a solid surface that can be immediately covered with cladding material.

Drawbacks:

• its price is much higher;
• installation equipment required.

This is one of the more sophisticated forms of insulation, though it is rarely used because it costs more than other materials.

Step by step procedure

One wall can be finished in a single day due to the speed at which the work is done. You can perform the installation yourself.

Outside cinder block wall thermal insulation:

1. Preparing the walls. To do this, excess mortar is leveled off and the wall surface is cleaned. If there are chips and cracks, you need to fill them with a solution and wait until dry.
2. Applying primer. The surface is degreased to ensure safe attachment of the insulation.
3. Installation of the starting profile. It will serve as a support for the insulation. Consists of metal plates that are attached with screws and dowels directly to the wall. Gaps of 2-3 mm are left between the profiles to allow metal movement when the air temperature changes.
4. Applying adhesive composition to polystyrene foam. A ready-made mixture is purchased specifically for a specific brand of insulation.
5. Installation of insulation. The boards are pressed tightly against the wall one by one, starting work from the corner. The last elements in a row may need to be trimmed. Installation of insulation layers is carried out in a checkerboard pattern, each new row is shifted by ½ part of the element relative to the previous one. This is done so that the effect of them is distributed evenly across the wall.
6. At the corners, the layers should converge according to the principle of gear engagement, hanging over one another.
7. The seams between the layers are treated with sealant, excess product is removed.
8. Additionally, the insulation is attached to disc-shaped dowels. Their length should be twice as thick as polystyrene foam.
9. An adhesive composition is applied, corners and openings are reinforced separately with metal corner profiles.
10. Attaching reinforced mesh to glue.
11. Installing film waterproofing on brackets.
12. Installation of facing fabric. This could be plastering and painting, installing siding, clinker bricks, etc. Check that the correct side of the waterproofing film will be facing out before installation.

Internal thermal insulation of a cinder block wall:

1. Clear the wall of debris, remove small irregularities. If you need to repair cracks and chips, this is done immediately.
2. Apply primer, wait until it dries.
3. Install wooden blocks along the height of the wall at a distance of 40-50 cm from each other. Look at the width of the mineral wool, it should be 2-3 cm wider than the opening between the bars so that the material is easily held inside.
4. Lay the insulation, secure it with disc dowels.
5. Cover with a mineral vapor barrier film, secure it to the brackets with a construction stapler on the bars.
6. Attach thin boards on top of the bars as a base for the finishing material.
7. Attach plywood or drywall to the profiles with self-tapping screws.
8. Apply finishing finishing (putty, paint, wallpaper or other).

Cost of work in the Russian Federation

The type of insulation, the quantity of work, the installation’s complexity, and the skill level of the artisans all affect the final cost of the project.

Name of works	Moscow and Moscow Region, rub/m2	St. Petersburg and Leningrad Region, rub/m2	Krasnodar region, rub/m2	Kazan, rub/m2
Insulating a cinder block wall from the outside	2000	2000	1900	1900
Insulating a cinder block wall from the inside	1600	1600	1500	1600

Method	Materials
Exterior Insulation	Polystyrene foam, mineral wool
Interior Insulation	Foam board, fiberglass
Spray Foam Insulation	Polyurethane foam
Insulating Plaster	Cement-based plaster with insulating additives

For a cinder block home, selecting the appropriate insulation is essential to guaranteeing both comfort and energy efficiency. The benefits of the different techniques and materials available vary, so it’s critical to take your needs and budget into account.

Resilient foam boards and spray foam are two excellent exterior insulation options that support the cinder block’s thermal mass. This method also increases the structure’s overall durability by shielding the blocks from weathering.

Installing interior insulation techniques such as foam panels or fiberglass batts can be less expensive and easier. These solutions still offer good thermal performance and can be combined with drywall to give the space a polished appearance.

The ideal technique and material will ultimately depend on variables like local climate, the state of the building, and personal taste. Making the best decision for your house with the assistance of an expert can guarantee that your cinder block house is warm and energy-efficient all year long.

Video on the topic

Real Example of Budget Insulation