How to work with glass wool when insulating external walls, the pros and cons of this material, the main stages of work on the facades - preparation, thermal insulation, final finishing. Insulation of the facade with glass wool is an opportunity to reduce heat transfer between the outer walls of the structure and the street. Thus, the owner of the premises can save on heating in the winter months and air conditioning in the summer. Thanks to external insulation based on glass wool, the useful volume inside the building does not decrease, and the temperature stabilizes.
Features of thermal insulation of the facade with glass wool
If you choose this material for yourself as a heater for the walls of a structure, then you should be familiar with its main specifics. Modern glass wool is much different from the one that has been known since Soviet times.
It is absolutely safe, does not irritate the mucous membranes, has a soft structure and low weight. Glass wool is widely used in construction, not only for heat and sound insulation of facades, but also floors, basements, external and internal walls.
According to the scope of application, there are individual varieties of this material. For horizontal external and internal surfaces, there is one type of insulator, for filling gaps and sound insulation of walls - others. Manufacturers produce glass wool in the form of slabs or rolls. If the work will be carried out on significant horizontal areas, it is better to purchase rolls, while the slabs are more convenient to use in small rooms and especially for finishing vertical walls.
Insulation of the facade with glass wool requires the use of a material with a low coefficient of thermal conductivity. This indicator can be found on the packaging or determined by the name of the product. Correctly selected insulation makes it possible to keep warm inside the rooms in winter, and protects the facade of the building from excessive heating in the summer months.
Advantages and disadvantages of glass wool facade insulation
This material has more than enough advantages. Let's highlight the following:
- Glass wool is chemically resistant to fire and various types of biological effects.
- It is not hygroscopic.
- Differs in good water-repellent qualities.
- Does not emit harmful impurities.
- Does not change its shape during operation.
- Quickly restores its appearance after being transported to the site.
- It has excellent sound and thermal insulation, vapor permeability.
- Able to withstand a temperature range from –200 to +500 degrees Celsius.
- Convenient for use in hard-to-reach places.
- Immune to chemicals.
- Differs in ease of installation.
- Affordable.
The disadvantages include the following qualities of glass wool:
- Contact with the skin during work provokes itching or burning of the skin. Work should only be done with protective gloves. It would be useful to use a protective suit and a respirator.
- The increased fragility and fragility of the fibers of this material is an additional inconvenience, since particles float in the air and enter the respiratory tract.
- Increase in thermal conductivity after wetting the material. Wet insulation serves as a source of cold, and it is rather difficult to dry it out, so if this happens, it is better to replace the glass wool section with new material.
- Over time, the insulator shrinks to some extent. This leads to the formation of gaps through which heat escapes. Compaction of the material with even more of it leads to a decrease in thermal conductivity.
- In terms of thermal insulation, it is inferior to mineral wool.
New grades of glass wool are much safer for the skin and respiratory tract than before, but the polymer component is still present in them.
Facade insulation technology with glass wool
All work should be divided into the stage of preparing the working surface, fastening the frame and glass wool itself, as well as finishing.
Preparatory work before installing glass wool
In order for the insulation to be truly durable and functional, it is necessary to pay great attention to the preparation of the walls. The working plane, on which the insulation will be carried out, must be free from air conditioners and other external elements: window sills, ebbs, grates, lanterns.
All electrical wires and communications that pass near the working surface must be hidden and insulated. The walls are freed from old plaster and any stucco elements. If they were uneven, then they must be leveled, after which you need to wait time for complete drying. If this is not done, then moisture will accumulate in the joints and cracks, which has a detrimental effect on the thermal conductivity of the insulation.
Before starting the insulation work directly, experts recommend laying a layer based on roofing roofing or polyethylene under the glass wool. It will serve as additional waterproofing of the facade. Its joints must be glued with adhesive tape.
Among the tools and equipment you will need: an electric drill, a pencil, a plumb line, a level, a knife with a long sharp blade, a spatula, and a screwdriver. Also prepare a protective suit, gloves, goggles, respirator.
Since the technology of attaching the insulation to the walls uses water in which the adhesive solution is diluted, all work should be carried out in dry weather with an ambient temperature of at least +5 degrees Celsius. This guarantees a long service life of the heat-insulating layer.
At the end of the preparatory work, special attention should be paid to areas covered with rust, oil paint, fungus, moisture, saline. Otherwise, the vapor permeability and adhesive qualities of the material can be significantly reduced.
Installation of a frame for glass wool
The construction of a frame based on metal suspension profiles is a necessary step before starting work with insulation material.
The technology of its fastening will be approximately as follows:
- A preliminary marking of the wall is made to fix metal suspensions for glass wool.
- Using an electric drill, holes are drilled in the surface at a distance of 40-60 cm. This is a step in a row, and horizontally adhere to a distance of 60 cm.
- The hangers are fastened by hammering in dowels.
- After that, their halves are bent forward, resulting in a U-shaped shape.
- To create the frame, not only vertical, but also horizontal bridges are used, which will hold the material in the cavity.
To reduce the transfer of cold by metal, wooden blocks pretreated with antiseptic solutions can become elements of the frame. Their cross-section should be approximately 40-50 mm, and mounting foam is put under each bar for additional sound insulation.
Instructions for installing glass wool on a facade
Consider the main work on wall insulation outside with glass wool, made in the form of finished slabs and in the form of a cotton material. Heat-insulating plates are attached to the walls of the building using glue or special umbrella-type dowels. You can use either one or both types of fasteners.
Instructions for fixing glass wool slabs:
- The glue is applied to the entire surface of the slab, then there is no need for additional dowels. You can apply it pointwise, for example, in the center and on the sides - in this case, special umbrella dowels, which are stuffed at a distance of 20-30 centimeters from each other, will help to hold the products.
- When cutting off finished pieces with a knife, they should be 1-2 centimeters larger than the cavity, which will allow the joints of the insulation to occupy space tightly.
- Material placement starts at the bottom and goes up.
- After fixing the boards on the wall or facade, the joints should be treated with a special adhesive solution.
- After the glue dries, the glass wool is covered with cladding.
- Then you can start fixing the mounting mesh, which is used to hold the grout.
- Finishing bricks do not need to be fastened back to back. If you retreat some distance from the slab, an air gap will form, which will provide additional insulation.
Features of installing cotton wool insulation:
- A crate should be built on the frame wall or facade, on which the cotton insulation will be fixed.
- Cotton wool is laid between the gratings in the frame space. To do this, it is cut into small pieces according to the size of the cells, slightly compressed and pushed into the cavity by compact villages with sticks.
- After that, the material is restored to its previous size and fills the space. A vapor barrier film is stretched over the frame, which is fixed on the bars with a stapler. You can attach it to the profiles with small screws.
- After laying the glass wool on the facade in the frame of the sheathing, it is worth fixing the cladding material on top. It can be a wagon board, drywall, chipboard or plywood. The sheathing is mounted on the same frame that was used to hold the cotton wool.
The installation of this insulating material is quite easy to master - no special professional skills are required. It can be placed in a cavity of any volume - glass wool expands and contracts so well.
Insulation of external walls and facades can also be carried out in two main ways - wet and dry:
- Wet … More common due to the affordability of the work. In addition, it makes it possible to use various types of facade insulation and decorative and finishing materials. When working with the wet method, several layers are sequentially attached to the surface: first, thermal insulation, then a glue-reinforcing layer and the final plaster. The main disadvantage of this technology is that to apply each subsequent layer, you need to wait until the previous one is completely dry.
- Dry … It consists in the use of a ready-made factory insulation. There is no need to be tied to the temperature regime - you can carry out insulation work all year round. The most commonly used technique is the "ventilated facade". Insulating glass wool panels are attached to the frame previously fixed on the wall. There is a gap of at least 4 cm between it and the insulation, through which air will circulate freely. He will be able to dry the cotton wool when moisture gets on it.
Decorative surface finish
After the glue with which the material was attached dries, the insulation of the walls with glass wool from the outside is practically finished. However, external finishing is required. To do this, a base layer of plaster is applied to the insulation, the thickness of which would be 3-4 mm. To avoid cracking its surface, reinforcement or applying a plaster layer along the mesh is used.
Last but not least, the finished and insulated facade can be covered with decorative plaster. Moreover, the thickness of its layer should not be greater than the filler layer. In addition, it will play the role of additional insulation and insulator. Most often, customers choose plasters based on acrylic, silicone or silicate. Each of them is characterized by the richness of texture and color, and is also capable of giving the facade a qualitatively new relief.
When choosing a type of plaster, you need to pay attention to the type of texture, since each of them is intended for specific finishing work. In order to further protect the facade of the building from the negative effects of external factors, it is recommended to paint the surface in colors that suit the design.
Some sections of the outer wall require a reinforced plastering layer. These are door and window openings, basement, corners of the building. To obtain an optimally flat surface, plaster beacons are used. Along the wall, along its entire length, a working cement mortar is thrown. It is applied in two stages if the thickness of the plaster layer is more than 15 mm.
After the solution has set, the plaster is applied. It is thrown in with a small margin, which can later be leveled with a spatula. It is important to ensure that the working surface of the tool does not deviate far from the wall level, but moves down and up with smooth swaying.
When planning the work on the final plastering of the facade, it is necessary to complete the decoration of each of the walls within one day. If this fails, then there is a risk of unwanted marks on the surface. When choosing materials that will be used at various stages of work, it is necessary to pay attention to the correct ratio and selection of their components. No one wants to get crumbled plaster or areas through which cold will penetrate instead of a beautiful and insulated facade. In the building materials market, you can easily select those brands of mixtures and mortars that have earned good recommendations over many years of use.
The main mistakes when insulating facades with glass wool
Most of these errors lead to cost overruns and significant heat loss. We draw the attention of everyone who is going to carry out work on the insulation of the building to the following points:
- Insufficient amount of insulation installed … It is taken into account what material the facade of the building is built from, since one needs 5 cm, while the other may need 20-30 cm of an insulating layer.
- Bad fasteners … Most often it is associated with glue of dubious quality and the refusal to use additional fixing dowels. Saving on this will lead to the fall off of whole layers of glass wool.
- Sloppy styling … Another common mistake. Plates should be located as evenly and tightly as possible, without cracks and gaps.
- Poor preparation of the base … The priming and leveling of the working surface guarantee a reliable fit of the insulation and all subsequent layers.
How to insulate a facade with glass wool - watch the video:
Today, with the help of glass wool in rolls and slabs, it is possible to insulate facades and external walls of absolutely any building. Due to its excellent thermal conductivity and low price, it will serve as an excellent solution for processing residential, office and industrial buildings. To work with it does not require many years of qualifications or special, expensive tools.
