- Benefits of a wet facade
- How to choose insulation for a wet facade
- Styrofoam (expanded polystyrene)
- Mineral wool
- Wet facade technology
- First step. Fastening the insulation layer of the building material to the wall surface
- Second phase. Base coat application
- Stage three. Decorative layer
- Wet Facade Repair Tips
A wet facade is one of the unique building technologies that can be used in exterior decoration on almost any type of buildings and structures. This article will describe the production process, materials used and tips for repairing the facade..
A wet facade refers to external finishing types of construction work, in which (together with finishing) the building is insulated.
Benefits of a wet facade
A wet facade, in contrast to a ventilated one, does not radically change the appearance of a building or structure, giving it additional characteristics – insulating and (if necessary) changing the color gamut by painting it in the desired color, and it can be painted repeatedly without removing the old paint layer. In addition, the wet facade has a small number of freezing points – cold bridges, minimizing the amount of condensate and its freezing.
In addition, the benefits include:
- excellent heat and sound insulation properties;
- easy to repair.
Among the shortcomings, it is worth noting the following:
- weak resistance to physical stress;
- installation and repair works are carried out only in the warm season.
This technology can be incorporated according to the project – that is, the walls of the building are erected without insulation, and during the overhaul of buildings.
In any case, a wet facade is performed on the already finished wall surface and according to standard technology, the height of the building does not matter.
The advantages of using this technology of construction work are obvious – you can build or restore any building without problems, choosing the type of insulation and plaster, which can be of a wide variety of textures and painted in any color, which will give the structure the necessary heat-retaining (insulating) qualities and a decent appearance.
How to choose insulation for a wet facade
Wet facade technology involves the inclusion and installation of several layers. The main layer on which the plaster is applied is one or two (less often three) layers of insulation.
For insulation of buildings and structures in the production of exterior decoration, two types of the most common building insulating materials are used:
- expanded polystyrene (in common people – polystyrene);
- mineral wool.
Both of these materials should be designed specifically for external finishing work – the foam must be marked “F”, which means facade, and the quality certificate of the mineral wool should indicate that it is intended for a wet facade.
From the point of view of financial costs, mineral wool costs on average 2-3 times more expensive than foam. Prices fluctuate depending on the season and order volume.
So which material to choose for thermal insulation? It all depends on the type of building and the goals set.
Styrofoam (expanded polystyrene)
Polyfoam (by the way, the building material most used in this type of work) is very easy to process – cutting and grinding. It creates not only a perfectly flat surface of the walls (with proper installation), but also with its help you can create various architectural decorations on the facade of the building.
Note:expanded polystyrene (aka polystyrene, aka PSB-F) is a gas-filled plate building material obtained from polystyrene in a chemical production, by foaming the material with vapors of low-boiling liquids.
Index Actual values Density, kg / m3 from 15.1 to 25.1 Compressive strength at 10% linear deformation, MPa, not less 0.1 Flexural strength, MPa, not less 0.18 Thermal conductivity in dry condition at 25 ± 5 ° С, W / (m? ° С), no more 0.035 Self-burning time, sec., No more 2 Humidity of slabs,%, no more 1 Water absorption in 24 hours,%, no more 2
- width – 1000, 1250 mm
- length – 500, 1000, 2000 mm
- thickness – from 20 to 1000 mm
The cost is from 1400 rubles / m3. Sold in packs from 0.25 m3.
- high thermal insulation qualities;
- light weight;
- easy to fit (cut) to the required dimensions.
- combustible (despite the opposite statements of manufacturers), and during combustion it emits harmful substances;
- low durability.
Mineral wool is a hydrophobized slab material with the inclusion of particles of rocks of the basalt group, it is just as well cut to the desired size and perfectly bends around the rounded outlines of the facade elements. In addition, mineral wool is an excellent sound insulator and due to its less dense structure than expanded polystyrene, the structure better removes moisture.
Index Actual values Density, kg / m3 from 45 Compressive strength at 10% linear deformation, MPa, not less ten Flexural strength, MPa, not less – Thermal conductivity in dry condition at 25 ± 5 ° С, W / (m? ° С), no more 0.035-0.038 Self-burning time, sec., No more Not flammable Humidity of slabs,%, no more 1.5 Water absorption in 24 hours,%, no more 1.5
- width – 1000 mm
- length – 600 mm
- thickness – from 30 to 200 mm
Cost from 3000 rubles / m
- high heat and sound insulation qualities
- easy to cut
- uniform, uniform dimensions
- afraid of moisture;
- during work requires the use of additional personal protective equipment – glasses, overalls, respirator.
Determination of the type of insulation layer and its thickness must be carried out at the stage of building design. It is important that the building has the required thermal insulation coefficient and moisture does not accumulate in its walls, otherwise all the work will be done in vain. Penetration of water vapor into the wall will lead to partial freezing of the walls and, accordingly, the destruction of the insulating and decorative layer.
Wet facade technology
This type of construction work requires a number of tools and consists of three main stages.
- Fastening the insulation layer of the building material to the wall surface.
- Base coat application.
- Applying a decorative layer.
You will need the following tools for installation:
- building level – up to 2 m;
- knives and a hacksaw for cutting insulation;
- perforator for drilling holes and mixing adhesives;
- “Whisk” – mixing nozzle;
- UGShM – Bulgarian;
- spatulas of various shapes and sizes (flat, serrated) for applying adhesive and plastering compounds;
- buckets (you can use plastic from under the primer).
First step. Fastening the insulation layer of the building material to the wall surface
If the wet facade is carried out as restoration work, then it is necessary to make cosmetic or major repairs to the walls..
According to the technology, the first sheets of insulation are mounted from below, on a special metal profile, preferably with a stiffener capable of withstanding the calculated weight without deformation. Profiles of this type are not cheap, so they are usually neglected. But in vain – it serves not only to support the layer (s) of insulation, but also protects it from below from moisture falling on it – especially important for mineral plates. If, for a number of reasons, the profile was not installed, it will be described below how to protect the lower layer of insulation from moisture.
The profile is installed strictly horizontally – on a single or stepped level, It is attached to the wall using expanding anchors or dowel-nails.
The first or only insulating layer is attached to the wall using special adhesives. If mineral wool is used, then cement-based compositions are used. They are sold in the widest range in any hardware store – the main thing is that it matches the type of work performed. The glue consumption and mixing technology are indicated on the packaging bags. In case of technological necessity, the seams between separate adjacent boards are also coated with adhesive.
Polystyrene foam insulation can be fixed to the wall using a special foam glue, which is applied using a gun for spray cans with foam.
Before applying the glue, the surface is dust-free and primed.
Expanded polystyrene, due to its low weight, can be glued directly to the wall, and the mineral wool must first be primed with the same adhesive and allowed to “lie down”.
Finishing fasteners are made with dish-shaped dowel-nails, which are installed with a calculated pitch. Usually use 3-5 dowels per 1 m2 area. A sheet of insulation must be fixed in the center, and ideally in four corners, with the entry of the “plate” onto the adjacent sheets. In the presence of two or more layers of insulating material, the butt joints in the layers should not be under each other.
To do this, the second layer of insulation is shifted relative to the first by a quarter or half of its length..
Second phase. Base coat application
Since the base layer determines how durable the entire facade will be, it is impractical to save on it. Good building materials should be purchased.
In this type of construction work, a reinforcing anti-acid-alkali mesh (or simply a glass mesh) and dry glue are used.
The reinforcing layer of fiberglass mesh is fixed on the adhesive base, which is applied with a special notched trowel. The mesh is pressed into the glue immediately after applying it to the wall surface (insulation). If necessary (especially on the first floor), the mesh can be mounted in two layers – in this case, the second layer is applied in the same way as the first.
Separate, especially strong corners of a reinforcing mesh are mounted on the corners of the building – they are sold in any hardware store, they are inexpensive.
Advice:if there is no starting profile, then the mesh is taken with such a margin that it can be tucked under the insulation – this is done at the stage of installation of the insulation layer so that it is possible to rigidly fix the fiberglass mesh to the wall – base.
Since work on the construction of a wet facade is carried out in the warm season, the base layer must be protected from direct sunlight (otherwise it may crack) and from atmospheric precipitation (it can wash off) for about a day. Matte polyethylene is ideal for these purposes, from which the canopy is made..
After drying, the unevenness of the adhesive can be sanded with ordinary sandpaper.
Stage three. Decorative layer
The decorative layer directly depends on taste and financial capabilities. It is applied according to the manufacturer’s instructions..
The fastest, cheapest and most widespread method is to apply two coats (one will definitely not paint over) acrylic water-based paint. For a primer, you can use the paint itself, diluting it with water.
The use of mineral plaster, a cement-based building material, will be slightly more expensive. It gives the surface of the walls a different texture (for example – “fur coat”, “bark beetle”, etc.), has a light background – but it also needs to be painted.
Further, in ascending order, there are silicone plaster compositions with a filler of fine granite chips.
Well, the most expensive decorative layer is considered to be mosaic plaster. The high cost is due to the fact that it contains colored chips (stone) and transparent resins. After hardening, this plaster forms a smooth glassy top layer..
Wet Facade Repair Tips
At the beginning of the main production of work, it is necessary to record or save all documents accompanying building materials, which indicate the exact tinting of the paint, the name and composition of all mixtures. This is necessary so that the freshly painted stain does not differ in color. An exception is the façade of the building that has burnt out over time..
When decorative plaster lags behind, cleaning is carried out to a tightly adhering layer. After that the cleaned surface is prepared – sanded, primed and a layer of plaster is applied.
In case of replacement of part of the insulation layer, the same material is used.
This is how it is quite simple to insulate and give an attractive appearance to any building..