Technology of warming wet facade

Walls of houses erected from a brick, various wall blocks, and even more so - representing a reinforced concrete structure, in most cases do not meet the requirements for a standard thermal insulation. In a word - such houses need additional insulation to prevent significant heat loss through the building's enclosing elements.

Warming technology wet facade

There are many different approaches to the thermal insulation of external walls. But if the owners prefer the exterior decoration of their house, made of decorative plaster, in a "clean" form or with the use of facade paints, then the optimal choice is the technology of warming the wet facade. This publication will consider how difficult such work is, what is required for their conduct, and how all this can be done on its own.

What is meant by the "wet facade" thermal insulation system?

First of all, it is necessary to understand the terminology - what is the technology of the "wet facade", and what is it different from, ck(siding, block house, etc.)

The technology allows both to insulate and decorate the facade of the building

The hint lies in the name itself - all stages of the work are carried out using building materialscompositions and solutions that are diluted with water. The final stage is the plastering of already insulated walls, so that the thermally insulated walls become completely indistinguishable from ordinary ones covered with decorative plaster. As a result, two important tasks are solved immediately: ensuring reliable insulation of wall structures and high-quality facade design.

The approximate scheme of warming using the technology of the "wet facade" is shown in the figure:

Basic scheme of insulation using the "wet facade" technology

1 - the insulated façade wall of the building.

2 - a layer of a building glutinous mix.

3 - insulation boards of synthetic( polystyrene foam of one type or another) or mineral( basalt wool) origin.

4 - additional mechanical fastening of the thermal insulation layer - dowels - "fungi".

5 - protective and leveling plaster layer reinforced with a mesh( item 6).

7 - decorative plaster finishing of the facade.

This system of complete thermal insulation and facade decoration has a number of significant advantages:

• It does not require a very material-intensive installation of the frame structure.
• The system is quite light. And it can be successfully applied on most facade walls.
• Frameless system predetermines and almost complete absence of "cold bridges" - the insulating layer turns out to be monolithic throughout the surface of the facade.
• Facade walls receive, in addition to insulation, and an excellent soundproof barrier, which helps reduce both air and impact noise.
• With the correct calculation of the heating layer, the "dew point" is completely removed from the wall structure and is taken out. Excludes the possibility of blotting the wall and the appearance of mold or mold colonies.
• The outer plaster layer is characterized by good resistance to mechanical stresses, to weathering.
• In principle, the technology is simple, and with strict adherence to rules, any homeowner can handle it.

If desired, the exterior finish of the facade can be updated

• With high-quality work such a heated facade does not require repair for at least 20 years. However, if there is a desire to update the finish, then this can easily be done without violating the integrity of the thermal insulation structure.

The drawbacks of this method of insulation include:

• Seasonality of work - they can only be carried out with positive( not less than + 5 ° С) temperatures, and with stable good weather. It is undesirable to work in windy weather, if the air temperatures are too high( above + 30 ° C), from the sunny side without providing protection from direct rays.
• Increased demand for both high quality materials and accurate adherence to technology recommendations. Violation of the rules makes the system very vulnerable to cracking or even peeling off large fragments of insulation and finishing.

Insulation was clearly carried out with a violation of

technology. As a heater, as mentioned, mineral wool or styrofoam can be used. Both materials have their advantages and disadvantages, but still for a "wet facade" a quality minvata looks preferable. At approximately equal values ​​of the heat conductivity index, the mineral wool has a significant advantage - vapor permeability. Surplus moisture free will find a way out of the premises through the wall structure and escape into the atmosphere. With expanded polystyrene is more difficult - it has low vapor permeability, and for some types it generally tends to zero. Thus, the accumulation of moisture between the wall material and the insulating layer is not excluded. This is not good enough by itself, but at abnormally low winter temperatures, cracking occurs and even "shoots" of large areas of insulation along with finishing layers.

There are special topics for expanded polystyrene - with a perforated structure, in which this issue is to some extent solved. But basalt cotton wool has one more important advantage - absolute incombustibility, than polystyrene foam can not boast in any way. And for the front walls this is a very serious question. And in this article we will consider the best option - the technology of warming the "wet facade" with the use of mineral wool.

How to choose a heater?

What mineral wool is suitable for a "wet facade"?

As it is already clear from the basic scheme of the "wet facade", the insulation must be mounted on one side to the adhesive solution, and on the other hand - to withstand a considerable load of the plaster layer. Thus, thermal insulation boards must meet certain requirements in density, in ability to withstand loads - both in the rumple( compression) and in the breaking of their fiber structure( stratification).

Naturally, not every heater, classified as a mineral wool, is suitable for these purposes. Glass wool and slag wool are excluded completely. Applicable only plates made of basalt fibers, produced by a special technology - with increased rigidity and density of the material.

Leading manufacturers of heaters based on basalt fibers in their product line provide for the production of slabs specially designed for thermal insulation of walls with subsequent finishing with plaster, that is for a "wet facade".The characteristics of the several most popular species are given in the table below:

Parameter name	"ROCKWOOL FASAD BATTS"	"Baswool Facade"	"Izovol F-120"	"Technonikol Technofas"
Illustration
Density of material, kg / m³	130	135-175	120	136-159
Strength limit, kPa, not less
- for compression at 10% deformation	45	45	42	45
- for stratification	15	15	17	15
Thermal conductivity coefficient( W / m × ° C):
- calculated at t = 10 ° C	0,037	0,038	0,034	0.037
- calculated at t = 25 ° C	0,039	0,040	0,036	0,038
-operational under the conditions "A»	0,040	0,045	0,038	0,040
- operating under the conditions of "B»	0,042	0,048	0,040	0,042
Group flammability		NG NG NG		NG
class fire	KM0	-	-	-
Water vapor permeability( mg /( m × h × Pa), not less than	0,3	0,31	0,3	0,3
Partial immersion moisture absorption	not more than 1%
Plate dimensions, mm
- length and width	1000 × 600	1200 × 600	1000 × 600	1000 × 500 1200 × 600
- plate thickness	25, from 30 to 180	from 40 to 160	from 40 to 200	from 40 to 150

It is not necessary to experiment with lighter and cheaper types of basalt wool, as such"Wet facade" certainly will not last long.

How to determine the required thickness of insulation?

As can be seen from the table, manufacturers offer a wide range of insulation thicknesses for the "wet facade", from 25 to 200 mm, usually in 10 mm steps.

Slabs for facade work can have different thicknesses

Which thickness should I choose? This is by no means an idle question, since the created system of a "wet facade" should provide high-quality thermal insulation of walls. However, excessive thickness - this is unnecessary costs, and in addition, excessive insulation can even be harmful in terms of maintaining the optimal temperature and humidity balance.

Usually the optimal thickness of insulation is calculated by specialists. But you can do it yourself, using the calculation algorithm below.

So, the insulated wall must have a total resistance to heat transfer no lower than the normative value determined for this region. This parameter is tabular, it is in the reference books, it is known in local construction companies, and in addition, for convenience, you can use the map-scheme below.

Map-scheme with normalized values ​​of thermal resistance of building structures

A wall is a multilayer construction, each of its layers has its own thermophysical characteristics. If the thickness and material of each layer, already available or planned, is known( the wall itself, internal and external trim, etc.), it is easy to calculate their total resistance, compare it with the normative value in order to obtain a difference that must be "covered" byadditional thermal insulation.

It will not bore the reader with formulas, but we immediately suggest using the calculation calculator, which quickly and with a minimum error calculates the required thickness of insulation with basalt wool, designed for facade work.

Calculator for calculating the thickness of the insulation of the wet facade system

The calculation is carried out in this order:

• Determine the normalized value of the resistance to heat transfer for the walls( purple figures) according to the map-scheme for your region.
• Refine the material of the wall itself and its thickness.
• Determine the thickness and material of the interior walls.

The thickness of the exterior plastering of walls is already taken into account in the calculator, and it does not need to be added.

• Enter the requested values ​​and get the result. It can be rounded up to a standard thickness of the produced insulation boards.

If a negative value is suddenly obtained - no wall insulation is required.

What other materials and components required?

In order to determine the materials, it is necessary to consider the scheme of the future "wet façade" once more in details.

Materials and components required for warming using the "wet facade" technology

1 - starting( socle) profile. Its width should exactly correspond to the thickness of the insulation. The number of profiles corresponds to the perimeter of the insulated walls.

2 - connecting elements for socle profile. Ensure the exact joining of the profiles in one plane and set the necessary temperature gap between them. Quantity - one for each joint, or two for a thickness of 100 or more.

3 - profile fastening. Spacer nails must have a length of at least:

- for concrete walls or laid out of solid brick - 40 mm;

- for walls made of hollow bricks - 60 mm;

- for gas silicate blocks or other low-strength materials - 100 mm.

It is not difficult to calculate the number of fastening points: for thermal insulation 80 mm thick and above, a step of 300 mm, with a thickness of less than 80 mm, can be installed in steps of 500 mm.

A spacer washer is provided for each attachment point - for precise alignment of the profile.

4 is a primer for the preparation of a wall for bonding slabs.

- For brick, plaster or gas-silicate walls, the best choice will be a deep penetration soil. The average flow is 300 ml / m².

- For concrete walls, a "concrete contact" type soil is purchased. The average flow rate is 400 ml / m².

5 - adhesive compound for the installation of insulation boards. It should be designed specifically for such tasks - for fixing the thermal insulation layer.

Different kinds of adhesive compounds for thermal insulation work

There are many varieties of it - usually minvat producers give their recommendations on the most adapted compositions or even offer their own branded mixtures.

Average consumption of adhesive at this stage of work is approximately 6 kg / m².

6 - insulation boards with a calculated thickness. The average consumption, taking into account the cutting and possible waste - 1.05 m² per 1 m² of the wall.

7 - dowels - "fungi" for additional mechanical fastening of a heater. The total length of the dowel must correspond to the thickness of the insulation plus the length of the spacer - depending on the material of the wall( see above).

Dowel "fungus" with metal nail and thermal head

It is more preferable to use dowels with a plastic spacer nail or with a core equipped with a special thermal insulating head - so as not to create "cold bridges".

Average flow rate - 6 pcs / m².

8 - basic protective reinforced plaster layer on insulation boards. A special plaster composition or the same glue composition used to mount the plates is used.

The thickness of the layer is 4 mm - for further application of decorative plaster, or 5 mm - if it is supposed to simply paint with facade paint. Based on this, the flow varies from 4 to 5 kg / m².

9 - reinforcing mesh made of alkali-resistant fiberglass. It is usually realized in rolls of 1000 mm width. The average flow is 1.1 meters per square meter of wall.

9a - not shown in the diagram, but in the process of work, you will definitely need reinforcing corners with mesh strips - for plastering corners on knocking walls and on window and door slopes.

PVC corner with reinforcing mesh strips

Consumption - according to the actual total length of all angles.

10 - primer water-dispersive - for the preparation of plastered surfaces for finishing works. The average flow rate is 150 ÷ ​​200 ml / m².

11 - decorative plaster of the chosen class. Consumption depends on the type of plaster and its specific qualities.

12 - exterior paint.

Points 11 and 12 already refer, rather, to finishing works, and will not be considered in the context of this publication.

Some manufacturers offer complete systems "wet façade" which include all the necessary materials - from insulation to finishing decorative plaster of facade paint, and a complete range of all necessary components. This is generally an optimal solution, since all components of the system are maximally adapted to each other.

The calculator below will help you quickly calculate the required number of basic materials for a wall of a certain area.

The area of ​​the wall is easy to calculate. For a rectangle, this is the product of length by height. If the wall has a complex configuration, other geometric relationships are used.

Need help identifying areas of complex shapes?

Special publication of our portal dedicated to calculation of areas , will help the reader to quickly and accurately make the necessary calculations.

Calculator for calculating the number of required materials

Carrying out work on the technology of the "wet facade"

To ensure that the walls are "wet-faced" according to the principle of "wet façade", it is quality and durable, it must be strictly phasedabout, with exact observance of all technological recommendations. Each step is important, and ignoring this or that operation will inevitably lead to marriage.

Preparation of the wall surface for insulation work

If the facade is insulated by such a technology, the thermal insulation will only be effective if the maximum contact between the wall and the warming layer is ensured. And this, in turn, means that careful preparation of surfaces is of the utmost importance.

• The plates will be mounted on the glue, but it is designed for "clean" wall surfaces, without paint residues. If the facade was previously painted, then it must be cleaned to a base base or a stable plaster layer.

Walls for this kind of insulation require high-quality cleaning

Cleaning can be done mechanically, using heating with a construction hair dryer or using special washings - depending on the specific baseline conditions. But the goal is one - the base must be clean, free from stains of paint, oiled or bitumen-impregnated plots.

• You can leave the old plaster only if its condition does not cause any concern. This must be verified by conducting a thorough check with a tapping - unstable patches should be removed without any pity.
• Do not work on a wall on which there are even the slightest signs of mold, moss, fungus, etc. All this must be cleaned, and then the entire wall is treated with a special "treating" composition - in accordance with the instructions attached to it. Go to further steps can be only after the complete drying of bactericidal treatment.

The wall clearly needs "treatment" with the antiseptic compositions of

. However, even if there are no obvious signs of the destruction of the wall by microflora, it is possible to conduct such "health-improving" measures in any case.

• The wall should be flat enough. All potholes, removed areas, cracks, crevices need to be repaired - to be decontaminated, primed and densely filled with mortar, leveling these "patches" to the general level of the wall. The existing protrusions are knocked down - as well, to the general level.
• Revise the plane of the wall - vertically and horizontally. If there are significant deviations( more than 20 mm), then you should not expect to align them later, with a layer of insulation and subsequent decorative plaster - nothing good will come of it. Alignment will have to be carried out now, using the usual cement-sand plaster, which is optimal for a particular wall material. True, the work in this case will be protracted - it will be possible to proceed to the installation of insulation boards not earlier than 3 ÷ 4 weeks.
• All metal elements necessary for mounting antennas, drains, air conditioning systems, lighting, etc. should be pre-installed on the walls. These brackets should be immediately covered with anticorrosive primers.

All metal parts of the facade must be treated with

• anticorrosive primer. When the repair or plaster layer on the wall is completely dry, the entire surface is treated with a primer. The type of primer and its consumption has already been discussed above. Application is carried out by a roller or, in hard-to-reach places, with a brush. It is important not to miss the slightest patch. If an excessive absorption of the formulation is detected in any area, then it is not worthwhile to regret the primer - the place should be treated twice.

The field of drying the soil the first stage can be considered complete.

Mounting of the base profile

The base profile, on which the first row of insulation boards will be installed, must be mounted strictly along the horizontal "zero" line, which is beaten over the laser or water level. An important condition for high-quality insulation of the first floor - this line should be at least 300 mm below the floor level in the premises, so that there is no "cold bridge" left.

Correctly exposed profile solves two main tasks. It ensures the evenness of stacking of insulating plates and becomes protection from below, in that unique place where the mineral wool will not be closed by the plaster layer.

Scheme for securing the socle profile

The types of fasteners and the step of their installation have already been mentioned above. Plastic washers( 1) are used to compensate for slight curvature of the walls, if necessary, so that the profile is firmly pressed against the surface but at the same time - not deformed.

Profiles are never lapped - only buttwith the interval of 2-3 mm left. This is provided by the connecting elements( item 2) - one or two for each joint.

On the outer or inner corners of the wall, the profiles also join with the gap remaining. To do this, they are cut at an angle of 45 °, and at the junction site a connecting element is inserted. Another option is to cut an angle of 90 ° inside the profile, leaving only the outer boundary edge intact. Then the profile is bent at right angles, and at the joint the connecting element is also inserted. These measures will allow to maintain a perfectly flat horizontal line of profile along the entire perimeter of the building.

In the event that a heater thickness of over 80 mm is to be installed, the question of temporary stops under the starting profile should be considered so that it does not bend at the initial stage of gluing the plates. After the heater is mounted, these stops are simply removed.

Usually the socle profile is mounted immediately along the entire perimeter of the insulated walls. Then you can proceed to the next stage - to gluing the slabs.

Mounting of insulation boards

For the installation of boards, the adhesive composition is brought to readiness in exact accordance with the instructions attached to it.

The required amount of water is gradually added to the dry mix and at low speeds the mixer is gradually brought to the desired consistency, without lumps. Usually it takes at least 5 minutes. Then a pause is made - for 6 ÷ 8 minutes, and after that the composition is mixed again for 5 minutes.

The adhesive composition is diluted in strict accordance with the instructions attached to it

Do not immediately make too much of the mixture - the term of its "life" is limited, and the addition of water, when there are signs of seizure, will not do anything. If during the work there was a short break, about 10 ÷ 15 minutes, that the mix should be again mixed with a mixer.

Adhesive on the slab can be applied in several ways.

• This is usually done around the perimeter, with an indentation from the edge of 20-30 mm, strips of 100 mm thick, and also in the center - by three slides with a diameter of about 200 mm. The height of the applied layer is about 20 mm, but can vary somewhat( no more than +10 mm), depending on the degree of evenness of the base.

Recommended scheme for applying glue to

• boards. If the insulated wall is of excellent smoothness, it is possible to apply the beads on the entire surface using a notched trowel with a comb height of 12 mm.

In either case, it is recommended to apply glue in two stages:

- first a small amount of adhesive is rubbed into the surface of the plate with the force in the right place.

- then the required amount of formulation is applied.

In those places where the plate will be released around the corner or a slope, no glue is applied.

The slab is placed on the place intended for glue and tightly pressed against the surface of the wall. Light movements up and down and in the sides with a clamp to the surface ensure a uniform distribution of the glue. All surpluses that protrude along the edges are immediately removed with a spatula.

At installation of the next plate achieve as much as possible dense adjacency, without the slightest lumens. If the lumens can not be avoided, then they are subsequently densely filled with mined wedges cut out by wedges. Filling voids between blocks of glue - is strictly prohibited!

The laying is usually from one of the corners, in order. It is necessary to observe several important rules.

The basic principles of the correct location of

• insulation boards The first row should rest on the starting profile, exactly along the boundary edge.
• The slabs are laid "in the dressing", with a vertical joint displacement of at least 200 mm( position 1).
• The principle of a "toothed lock"( item 2) is observed at the corners.
• The slab fragment adjacent to the corner or slope can not be less than 200 mm wide( key 3).
• Normally, docking of wall and slope insulation, which is also performed with mineral wool plates, but of smaller thickness( item 4), is usually provided at once.

Special attention is required to abut the slabs to the slopes.

This arrangement of slabs relative to the edges of the slopes necessarily leads to cracks in the

. No matter how vertical and horizontal seams pass through the laying of the slabs, they should not coincide with the slope continuation lines, otherwise the plastering will inevitably crack in this place. If such a situation occurs when laying, then at the corners of the slopes are made inserts, the thickness of which both vertically and horizontally should be not less than 200 mm. Then these inserts can be cut to the size of the window opening.

This issue is solved by inserting the corners of the

opening. The cutting of the slabs is carried out using a hacksaw with a small tooth or a special knife.

Special knife for high-quality cutting of mineral wool boards

During the installation constant monitoring of the flatness of the resulting plane is conducted - until the adhesive mass has frozen. Still there is an opportunity to make certain adjustments. For control use a long rule and building level.

Adhesive mixture should be given about three days for complete drying, and then an additional mechanical fastening is done by the heater with the help of dowels "fungi".Usually on each plate is used 5 fixtures - in corners and in the center. Often, in order to save the dowels are installed in such a way that their hat simultaneously holds adjacent plates.

Recommended arrangement of dowels "fungi"

The drilling depth stopper is installed on the drill to ensure the required length of immersion of the dowel spacer in the wall + 15 mm.

Directly through a heater accurately, not allowing beating, the hole is drilled. The "fungus" is inserted into it and fixed by the spacer core. The hat should be lightly puffed through the layer of mineral wool for 0.5-1 mm. The central hole of the dowel must be covered with a thermo cap. If it is not - you can isolate it with a mounting foam.

Completing the installation of insulation boards by checking the surface for the absence of cracks or places loose fitting. All identified defects are eliminated by a dense insertion of wedges of mineral wool.

Application of the basic reinforced plaster layer

The insulated heater requires a covering with a protective reinforced plaster layer.as already mentioned, the same glutinous mixture can be used as the base material, but it is also possible to use a different solution recommended by the plate manufacturer and included in the general thermal insulation system. For example, in the Rockwool ROCKFASAD system, the use of a special plaster mix ROCKmortar is recommended. But the application technology does not change.

Stucco mix ROCKmortar

• The composition is diluted in the right amount( guaranteeing its production within 1 ÷ 1.5 hours) in accordance with the instructions.
• Work begins with the most difficult areas - from corners and slopes.
• Adhesive composition with a width of approximately 200 mm and a thickness of 2 mm is applied to the sides adjacent to the corner. It is advisable to walk with a notched trowel with a height of the crest 5 mm - so it will be easier to glue the reinforcement layer.
• Set the corner with mesh strips, strictly along the angle line.

Angle reinforcement with the use of a special profile

• With a conventional flat spatula, the mesh is pressed into the solution layer. It is important not to leave the "dry" areas, but at the same time the grid should stay in the thickness of the solution, and do not stick close to the heater.

On the slopes, the task is a little more difficult - here it is necessary to provide an abutment to the window or door structure. Usually I do so - a special contiguous profile( U-shaped) is attached to the window or door block. It starts a grid of the corner( item 1), and then the entire slope is plastered with the base layer, so that the reinforcement remains inside it. The total layer of plaster on slopes should usually be thicker than on walls - about 6 - 7 mm.

Approximate scheme of reinforcement of slopes

Additional reinforcement of the vertices of the corners of window and door openings is mandatory. To do this, cut out rectangular "kerchiefs", which are superimposed as shown in the figure( item 2) and are recessed into the plaster solution.

Now you can go to the surface of the walls. It is covered with plaster according to the same principle.

- The grid is cut by strips( it is not too long to get involved - it will be inconvenient).

- The adhesive is applied and distributed on the wall by a vertical strip of 1100 - 1200 mm, using a notched trowel.

- The first strip from the angle of the net is glued to the solution so that overlap is provided with the reinforcement already done about 100 mm.

- With the spatula force, the mesh is recessed into the applied( approx. 2 mm) mortar layer.

Utilization of the reinforcing mesh in the plaster layer

- The next strips are also laid with 100 mm overlapping both vertically and horizontally.

- From the bottom, the excess mesh is trimmed in the level of the socle profile.

Trimming excess reinforcing mesh

It is important to ensure a uniform distribution of the solution over the entire surface of the wall and complete "immersion" of the mesh. That is why the use of a notched trowel is seen as the most convenient method.

The glue should grit slightly - and it will be possible to pre-grout, so as to reach a uniform layer of approximately 2 mm. Then another layer of mortar is applied - also 2 mm, or 3 mm, if you do not intend to use decorative plaster, but only use façade paint.

When trowelling the second layer is already tasked to maximize the surface of the wall to avoid even small defects that may well manifest through the decorative finish.

Grouting the base plaster layer

After the plaster leveled surface completely dries( and it takes at least 72 hours), it is covered with a layer of water-dispersion primer, which will ensure reliable adhesion to the decorative coating.

If the work is carried out in a hot period, then during the drying of the plaster layer, it must be protected from direct sunlight - uneven evaporation of moisture can lead to the appearance of a grid of small cracks.

The finished surface becomes a "clean sheet" for any type of facade paint or plaster. But this is already the topic of a separate examination devoted to finishing works.

The work is completed with the application of decorative plaster or facade paint

. And at the end of the publication - a video lesson on the performance of wall warming using the technology of the "wet facade" using the materials of "Technonikol".

Video: warming on the technology of "wet facade"