Length calculation
If the fastener is chosen incorrectly, it will not hold the thermal insulation. And you will have to tear it off along with the attached sheets. How not to make a mistake and calculate the desired length immediately?
The task of the dowel is to fix the insulation to the main wall. This is where you need to get to. On the way to the hard surface lie:
- The heater itself
- The thickness of the adhesive composition (if any).
In addition, it is worth considering that the dowel must enter the wall to a depth of 50 mm.
Thus, we calculate the desired length using the formula:
L = H + I + K + W.
Here:
L is the required total length of the dowel;
H is the thickness of the heat-insulating layer;
K - the thickness of the old plaster or adhesive on which the insulation is attached;
I - fixing the dowel in a concrete / brick / wooden base of the wall (at least) 50 mm.
W - margin for the curvature of the wall.
For example, if you use 50 mm thick foam and use a thin layer of glue - 5-10 mm, a dowel 110 mm long is enough for you. If the wall is flat. But, if the wall skew reaches 50 mm, it is worth adding this indicator and then you need a dowel of 160 mm or more. If we increase the thermal insulation layer to 100 mm, in the latter case we need 210 mm of the rod length.
The nuances of installing thermal insulation
Fungi for fixing plates are fixed after preparing the base and gluing the material itself to it. Work is carried out in the following sequence:
- On the surface of the foam or mineral wool, the points of location of future fasteners are marked with a recommended interval of no more than 80 cm horizontally, 30 cm vertically. When thermally insulating bases with a complex shape or using individual pieces, it is worth drawing up a layout for the dowels in advance.
- A mounting hole with a diameter of not more than 10 mm is prepared in the insulation and walls.
- The mushroom is placed manually until the cap is completely pressed against the insulation.
- The spacer element is installed inside until the maximum stop is reached.
- Closing the cap with plastic (for varieties with a thermal head).
Upon completion of the installation of all dowels, the joints are sealed, the vapor barrier, reinforcing mesh and exterior finish are placed. The work is carried out after the adhesive has dried, it takes 2-3 days. If it is necessary to fasten to wood or metal, specialized options are used together with a plastic booster collar, the installation process in this case is almost indistinguishable.
The important nuances of the technology include the selection of the correct length of products and the calculation of their required consumption per 1 m2. The design is considered reliable when the spacer sleeve is deepened into the base by at least 4.5 cm; when working with porous or weak materials, this rate is advised to be increased to 10 cm.
Rates
| Brand | The foundation | D washer, mm | Fixing dimensions, mm | Case materials | Nail | Price, rubles |
| Bubel-mushroom for Tech-Krep insulation | Concrete, stone, brick, gas silicate | 60 | 10×100 | Polypropylene | 2,5 | |
| Same with thermostat | 16×100 | Polypropylene | White zinc coated steel | 9 | ||
| With metal nail | 12×100 | 5,6 | ||||
| Koelner with metal nail and thermal head | 10×200 | Yellow zinc plated steel | 14 | |||
| Booster cuff Rondol | Tree | 50 | — | — | 1,5 | |
| Telescopic fasteners TechnoNIKOL with a self-tapping screw | The bearing base of the roof: profiled sheet, concrete, wood | 10×200 | High strength polymer | Used with TechnoNIKOL metal self-tapping screws | 8,2 |
The cost of dowels for thermal insulation depends on the advancement of the brand, the quality of the material of manufacture and dimensions: the length of the sleeve and the spacer and the diameter of the washer. Products with a metal nail cost twice as much as polypropylene ones, fasteners with thermal heads cost an order of magnitude more expensive. Saving is not recommended, this affects the reliability of fixation, the only way to reduce costs is to purchase in bulk.
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The primary task for everyone involved in preparing the house for year-round living and warming is the choice of fasteners for thermal insulation. With the right choice, fasteners will help you forget about heat consumption for a long time and be sure that the thermal insulation fits tightly to the facade. In other cases, the products simply will not be able to securely fix the insulation.
Depending on the type of material used as a heater, the following types of products can be used for fastening:
Special dowel-nail based on plastic. Fasteners of this type are characterized by minimal thermal conductivity. Due to the plastic design of the nail, the products are lightweight and retain the integrity of the thermal insulation during the insulation of the building. At the same time, the price of dowel-nails is much lower in comparison with alternative fasteners. A mounting dowel with a plastic nail works well when attaching a light weight insulation.
Facade dowel for quick installation with a metal nail. Mounting dowel for fixing thermal insulation has greater strength. The maximum load that this type of fastening can withstand is up to 450 kilograms. The only drawbacks are the high thermal conductivity and the need for corrosion protection. Facade dowel-nail of this type is also suitable for working with heavy insulation and porous wall material.
Plastic dowels are divided into nylon and polypropylene. The former are used in the installation of thermal insulation to solid, hollow and wood materials. This is a universal mounting option. Polypropylene dowels withstand a much greater load of up to 750 kilograms on average. They have more strength.
Device and mounting scheme
Of the design features of the heat-insulating dowel, its fastening system should be noted, consisting of an expansion dowel equipped with a pressure disk and a nail with a special head. Its disk has a diameter of 60 mm, its surface is somewhat rough.
The presence of technological holes provides reliable fixation of thermal insulation to the surface of the base. The shape of the spacer zone has an optimal three-section design, which eliminates the possibility of pulling the dowel out of the hole and ensures reliable fastening.
The fastener is a plate driven dowel with a galvanized nail or a plastic nail. It is used for mechanical fastening of insulating material in the implementation of various solutions for facade systems, in particular for the installation of "wet" and ventilated facades.
Dowel attachment scheme
The scope of the driven building dowel is the fastening of heat-insulating and facing materials when performing work on the insulation of walls with polystyrene foam from concrete and brick, as well as walls made of other materials.
To perform installation work, the average consumption of dowels per 1 sq. m will be approximately 5-6 pieces. Their exact number required for installation is made by calculation.
For high-quality fastening of heat-insulating materials to walls exposed to a high risk of adverse weather conditions, you can use high-quality OMAX dowels with a metal or plastic nail.
Insulation - the material is loose, porous, and, as a rule, soft. As a result, they fix it specifically: in a spacer, on glue. However, with sufficiently voluminous construction work, it is necessary to use special fasteners - a dowel for insulation.
A few words about extruded polystyrene foam
Before proceeding to the technology of external insulation of the house, let's consider what a penoplex is. I must say right away that it is more correct to call this material extruded polystyrene foam, since Penoplex is the name of the manufacturer of this insulation.
Extruded polystyrene foam is made from regular expanded polystyrene (styrofoam). As a result of a special heat treatment, it acquires higher, and with them, properties that affect the installation technology and the scope of the material.
These properties primarily include:
- low level of moisture absorption;
- smooth structure.
Penoplex has a smooth structure
On the one hand, this allows the material to be used in adverse operating conditions, in particular, it can be used for facade insulation. But, on the other hand, penoplex has poor adhesion. Therefore, it is not even a facade material, and even more so it is not intended for a “wet” finish.
The most common mistake of beginners is that when insulating the facade, they work with foam plastic in the same way as with ordinary polystyrene foam. Some building resources “help” in this, for which unfortunate specialists write articles. The result of this approach is clearly visible in the photo below.
In the photo - the result of incorrect foam reinforcement
However, this does not mean that the insulation of the facade in a “wet” way using foam plastic will have to be abandoned. The technology, which I will discuss below, will allow you to perform a reliable and durable finish on top of this insulation.
For beginners, the question probably arises, why use foam plastic if it can be replaced with foam plastic, which is cheaper and has good adhesion?
The fact is that extruded polystyrene foam has several important advantages over polystyrene foam:
- has a higher strength, respectively, the facade finish is more durable;
- is a vapor-permeable material;
- thermal conductivity is lower than that of foam.
Therefore, it makes sense to use penoplex for a “wet” facade finish. As for the “dry” insulation, which is used for a hinged facade, this procedure practically does not contain any features.
Below I will tell you in detail how to insulate the walls from the outside with foam plastic in both ways.
An example of finishing a house using the “wet facade” technology
2 Features of the installation of thermal insulation
The installation technology of any slab insulation - polystyrene foam, polystyrene foam, or foam plastic, with dowels of the fungus type is identical. All work on insulation, in fact, comes down to the following algorithm:
- Preparation of the insulated surface;
- Installation of panel thermal insulation on the adhesive solution;
- Fixing panels with dowels;
- Processing of insulation joints;
- Installation of an insulating film;
- Sheathing of thermal insulation with decorative material, or plastering.
Before installing the insulation, it is necessary to prepare the surface - remove the plaster, repair cracks and irregularities, and degrease.
Further, panels of expanded polystyrene, polystyrene, or foam plastic are planted on a special adhesive composition that does not contain organic solvents - toluene and acetone. During installation, the adhesive mixture must be evenly distributed over the entire back surface of the insulation.
In order to avoid shifts of thermal insulation under its own weight, a metal profile is installed under the first row of plates, which assumes the function of a support.
At the end of the day required for the solution to dry, fungi are used to additionally fix the thermal insulation.
To drill holes, drills are used, the diameter of which is equal to the diameter of the leg, while the length of the hole should be a centimeter longer than the length of the dowel, so that dust that has collected in the hole does not interfere with reliable fixation.
Stages of fixing thermal insulation with dowels
Building codes and regulations define the following standards for the number of dowels used:
- To fix thermal insulation on internal walls, or on the facades of one-story buildings, five pieces are needed for each square meter of insulation - 4 in the corners, and one in the center of the panel;
- For mounting on the corners of buildings - 6 pieces each (fungi are installed parallel to each other);
- For fastenings on the facades of buildings with a height of 8 to 20 m, you need 7 pieces per 1 m² of insulation (in parallel + 1 in the center);
- For fastening on the facades of multi-storey buildings with a height of over 20 meters - 9 pieces per square meter of thermal insulation.
Fungi are best placed at the joints of foam or foam panels, since this method does not lead to a significant increase in holes in the thermal insulation, which negatively affect its effectiveness.
If the dowel-mushroom needs to be installed in a metal coating of corrugated board, a self-tapping screw is attached to the dowel leg, after which the thermal insulation is pressed through so that the self-tapping screw reaches the insulated surface.
After that, using a screwdriver, the dowel with a self-tapping tip is screwed into the metal. The depth of the hole for the self-tapping screw should be at least 10-15 millimeters.
Upon completion of the fastening of the thermal insulation, the joints between the foam or foam panels are glued with aluminum reinforcing tape. The joints between the floor or ceiling and adjacent panels are sealed with mounting foam.
Sometimes they additionally make a blind area around the house. to the menu
Expert Answers
Sources
- http://stroyres.net/metallicheskie/metizyi/dyubel/dlya-uteplitelya.html
- https://uteplix.com/materialy/dyubelya-dlya-krepleniya-uteplitelya.html
- http://UteplimVse.ru/dybely/gribok.html
Types and characteristics of fasteners
This group is divided into dowels with an expandable sleeve and telescopic, used in conjunction with self-tapping screws. The first type is the most common, the extended wedging zone and the inner rod in this case pass through the slabs, plaster (if any) and go deep into the walls or ceiling by 4.5 cm or more. The edge of the spacer rod is slightly pressed into a wide dish-shaped hat, thereby pressing the thermal insulation layer to the working plane. A vivid example is TechnoNIKOL products - polymer tubular rods with a flange with a diameter of 50 mm are securely fixed with deep-going self-tapping screws made of durable metal.
According to the material of manufacture and design of the nail, polypropylene fungi for fasteners, metal and with a thermal head are distinguished. The first group includes dowels with a wide perforated head, expanded with a plastic rod, with a bearing load of not more than 380 N. They are used for light types of insulation, operated at temperatures from -40 ° C to +80 to vertical surfaces and facades with a solid base , their main advantages include low thermal conductivity (no more than 0.004 W / m ° C), good adhesion to concrete, brick and foam blocks, corrosion resistance and affordable cost. But for high-density species or when planning to protect the insulation layer with heavy building materials, they are not suitable.
Fungi, bursting with an impact-resistant metal nail, with an average size of 10 × 100 mm and a cap with a standard diameter of 60, withstand loads up to 750 N. They are selected if it is necessary to mount to the ceiling or finish facades with heavy stone wool slabs. In general, they are inferior to plastic varieties in corrosion resistance, but when used with options with good quality metal coating, they last a long time. But due to differences in the coefficient of thermal conductivity with the insulation itself, they form cold bridges, which reduces the effectiveness of external insulation, with an increase in the number of fasteners, this disadvantage is more pronounced.
Optimal characteristics in terms of resistance to corrosion, load bearing and elimination of heat loss are observed in dowels with a thermal head. The steel rod in this case is covered with plastic, the products are not affected by external influences. The scope of application is almost universal and includes the installation of any thermal insulators to bases made of ordinary and lightweight concrete, brick, stone and wood, the slope of the working surface does not matter. The only downside is the high price.
What should be considered when choosing?
The consumption of fasteners per 1 m2 depends on the type of structure, its height and location. On ordinary sections of the facade, 4-5 pieces are enough, at the corners - 6, when insulating the second floor of buildings - 7, houses above 20 m - 9.In addition to height, the thickness and density of thermal insulation, wind loads and the weight of the future finish are taken into account. The permissible maximum is 10 dowels per 1 m2, it is not recommended to violate it due to the risk of cold bridges and economic inexpediency.
When choosing an option for expanded polystyrene, preference is given to varieties with a rough hat from the inside
Attention is drawn to the quality of anti-corrosion treatment, at the risk of precipitation penetrating inside or when insulating high-rise buildings, the most expensive types with a metal spacer and a plastic thermal head are bought. The characteristics to be taken into account in addition to the withstand load, weight and dimensions include the temperature range of operation, in the northern latitudes it is not recommended to use products for external insulation with a plastic nail due to the risk of cracking
The layout and the total number are thought out in advance, after choosing the thermal insulation and calculating the thickness of the layer.
Varieties of fasteners
The shape of the product is determined by the specifics of the material to be fixed: a light and loose heat insulator cannot withstand rigid fastening. The plastic clamping disc, as it were, supports the insulation, and does not fix it.
However, fasteners may differ in the arrangement of the spacer and the material of manufacture.
By design
There are 2 main mounting options.
- Bezrasporny - the dowel is not completed with a hardware and does not need it. Fasteners are inserted into the drilled hole through the heat-insulating material. In the wall or ceiling, the dowel is held by structural protrusions.
- Spacer - in this case, there is a nail or screw, which, when twisted or driven in, bursts the body of the rod. The latter is held in the wall material due to the force of friction.
The expansion option is more often used when fastening to a dense material - concrete, solid brick, and the non-expansion option is suitable for cellular concrete.
By material
For the manufacture of the dowel, only plastics are used, the screw, if any, can be made of plastic or metal.
- Polyamide - or nylon. Durable lightweight material suitable for installation in any surface: brick, concrete, wood, hollow brick. The maximum load can reach 120 kg, working, respectively - 30 kg.
- Polypropylene - has a higher strength, hardness, the maximum load can reach 150 kg. Working for dense material will be about 40 kg.
- Fiberglass-reinforced polyamide is a relatively new material, which is not much inferior to metal in strength, but does not have its drawback - high thermal conductivity.
The spacer rod can be made of the same plastic, including reinforced plastic, as well as metal. The bearing capacity of the latter is higher, but they somewhat violate the thermal insulation.
Used:
- galvanized steel - with a zinc thickness of at least 6 microns;
- stainless steel - fasteners are much more expensive, but absolutely resistant to corrosion. Used in rooms with high humidity.
About the design that the dowels have for attaching the insulation to the wall and other surfaces, read below.
Structural version
This refers to the combination of execution materials. There are 3 options:
- dowel and nail are made of the same plastic. It is not recommended to combine different plastics, since each of the materials is characterized by its own coefficient of thermal expansion;
- plastic dowel and metal rod - the fastening strength is obviously higher and reaches 1.9 kN. However, the metal conducts heat too well, and forms a cold bridge in the heat-insulating layer;
- a plastic dowel-mushroom for insulation and a metal rod with a thermal head - the nail head is covered with a nylon cap. The screw itself is inside the body of the rod. In this case, the cold bridge problem disappears.
About what dowel-fungus for fixing the insulation has dimensions, read below.
About what dowel-mushrooms for insulation are, this video will tell:
Parameters
There is no GOST article regulating plastic dowels for insulation. However, the requirements for the polyamide material for building dowels apply, and GOST specifies exactly which brand of plastic can be used and for which climatic zones.
Fasteners are distinguished by a large length: after all, the dowel must go deep into the wall through a rather large layer of thermal insulation.
The rest of the sizes vary very little:
- the size of the cap ranges from 45 to 90 mm in diameter;
- on plastic there are only 2 diameters of the rod - 8 and 10 mm;
- the length of the product ranges from 40 to 400 mm.
The bearing capacity depends on the strength of the fasteners and the material of the wall. The load ranges from 0.3 kN to 23 kN.
| 10*80 | 2 | 10*90 | 15 |
| 10*90 | 2,5 | 10*120 | 16,75 |
| 10*100 | 6 | 10*140 | 20 |
| 10*120 | 8 | 10*160 | 32,2 |
| 10*140 | 9,8 | 10*180 | 44,5 |
| 10*160 | 11, 25 | 10*200 | 57,5 |
| 10*180 | 13,8 | 10*220 | 62 |
| 10*200 | 14,5 | 10*260 | 81,3 |
| 10*300 | 105,5 |
Read below about fixing insulation plates with dish-shaped dowels.
