Construction - External walls

Direction: energy efficiency, acoustic comfort and impressive elevations

External walls are one of the most important elements of the house - they transfer loads from the roof and ceilings to the foundations, isolate the interior of the house from the cold, weather conditions and noise coming from the outside. Modern technologies of production of building materials enable better and better fulfillment of these functions.

Low U-value. In the construction of an energy-efficient house, the choice of the type of external walls and materials from which they will be built is the key decision - 20-30% of heat escapes from the home through external walls. The heat transfer coefficient U depends on whether the wall has adequate thermal insulation. According to the regulations, it can not exceed 0.3 W / (m².K). However, if the house is to be energy-efficient, the heat transfer coefficient U of the walls should not be higher than 0.2 W / (m².K).

Materials with high thermal parameters. The offer of materials from which you can build warm walls is rich: cellular concrete, pottery ceramics, silicates, expanded ceramics. In the case of laminar walls, the final result consists of a layer of insulation.Manufacturers offer "warmer" versions of traditional thermal insulation materials: the so-called gray styrofoam (called neopor) and new generation mineral wool, but modern insulation materials, such as PIR polyurethane foam, are becoming more and more popular, which allows to maintain a low value of heat transfer coefficient with a lower layer thickness compared to traditional thermal insulation or moisture-resistant polystyrene extruded. It is important that the insulation material has the smallest heat conductivity coefficient λ .

Complete insulation systems. The thermal insulation material must be selected for the insulation method. Today, manufacturers offer comprehensive thermal insulation systems, which include insulation materials, plaster and the necessary construction chemicals. The choice of a complete system is a guarantee of maintaining the appropriate thermal insulation of the wall and ensuring permanent protection of the façade.

Ecological approach. Taking care of the energy efficiency of the house is also a favorable environment - the less energy we use to heat the building, the less fuel we use. However, energy efficiency is not the only parameter of the ecological approach. What counts is also whether the material for building walls is made of natural resources, which is energy-intensive during production and what are the possibilities for its subsequent disposal. The selection of material for walls is the resultant of all criteria.

Energy-efficient, not just masonry. Thanks to the new generation insulation materials, today's frame houses can achieve the parameters of energy-efficient and even passive buildings. There are also energy-efficient houses built from prefabricated elements - walls in a frame construction filled with thermal insulation with plating from panels and an additional layer of insulation outside as a finished element are created outside the construction site.

Difficult compromises. The choice of the type of external walls entails not only economical but also usable consequences, so it should be thought through in terms of energy efficiency, but also adapted to the needs and capabilities of the investor.

Fashionable elevations. The outer layer of the walls builds the image of the house. It may be that the façade material of our choice imposes a kind of wall, eg façade brick is associated with the need to build a three-layer wall. A real renaissance experiences a wooden panel much more durable than it used to be thanks to modern chemical agents for wood protection, as well as the use of new species or so-called. termodrewna. For single-family housing also penetrate other materials until recently used mainly in large format construction: fiber-cement boards, panels or coffers from sheet metal, HPL laminated boards or ceramic panels.

TECHNOLOGY FOR CONSTRUCTION OF EXTERIOR WALLS

Technology of building external walls

Masonry walls. This type of external walls is the most popular in our country. Masonry walls can be erected from various materials - cellular concrete, ceramics, silicates or expanded clay. They are characterized by high durability and thermal inertia - they accumulate heat well and slowly release it into the environment. Appropriate thermal insulation of masonry walls can be provided easily, mainly through the use of a suitable thickness of insulation. Brickwork technology has been used for years, that's why materials for the construction of such walls are widely available, it is also easy to find professionals who will solidly make a warm house wall. The construction of a brick house can be extended in time - an important advantage if the house is created using the economic method. However, erection of masonry walls is time-consuming and labor-intensive, and the need to carry out wet works forces technological breaks and suspension of construction for the duration of winter.

Skeletal walls. The most important advantage of the skeletal walls is the speed of their construction - in a skeletal home you can live after 3 months from its beginning. Although the skeletal walls are not as popular with us as the brick ones, it is easier to find a reliable, appropriately specialized executive team. Due to the material used to make skeletal walls - properly prepared wood - such houses are considered ecological.

Wooden walls. They are usually made of logs, wooden logs insulated from the inside with insulating material or laminated logs (with insulation placed between two layers of beams). Wooden walls rise quickly and without the need for technological breaks.They provide a beneficial microclimate at home, they are ecological, they heat up quickly and accumulate heat. The construction of walls made of logs requires finding a specialized, tested execution team and properly prepared wood. Because this technology is not very common in our country, it is relatively difficult to control the correctness of wooden structures. It is also an expensive type of walls - properly dried and impregnated balls are not cheap.

TYPES OF MUROWANY WALLS

Thermal insulation of the external wall

Single-layer walls. They consist of one layer - a carrier, which is a structural wall finished mostly with plaster. Such walls have both a protective and insulating function, so they should be made of a material that will provide them with adequate strength and thermal insulation. The construction of single-layer walls is relatively fast, however, due to the fact that the wall will not be covered with insulating material, it needs very careful workmanship. Particular attention and insulation need places exposed to the formation of thermal bridges (such as rims or headers). The construction of single-layer walls is cheaper than in the case of layered walls. Such walls, although they consist of one layer, can be characterized by good thermal insulation. On the market, one can find materials for single-layer walls that enable the building of energy-saving walls, whose heat transfer coefficient U is 0.19 W / (m².K). Such walls can therefore be as warm as layered. Single-layer walls are also more vulnerable to mechanical damage than those covered with insulating material.

Two-layer walls. They consist of two layers - a masonry carrying layer and an insulating layer, which is usually made of polystyrene or mineral wool. This type of walls is most often used in the construction of energy-efficient houses. The appropriate thickness of the insulation layer allows to achieve the required thermal insulation of the walls. Two-layer walls well insulate the interiors of the house against noise coming from outside. Although they are more expensive to manufacture and require more time and work than the construction of single-layer walls, they are more resistant to executive errors - possible oversights can be hidden under the insulation layer. However, it takes great care to arrange the insulation layer, which is of key importance when it comes to energy efficiency of these walls. Double-layer walls can be finished with the light wet method (in the ETICS system, formerly BSO) or light dry. In the light method, wet styrofoam or wool is attached to the wall, then covered with cement and lime mortar, pulled by a fiberglass mesh and plastered. In the light dry method, a special construction grid (usually wood) is fixed to the wall, thermal insulation is fixed between the elements, then a grating is made to provide a ventilation slit and the whole is finished with façade material - usually with wooden facing or siding.

Three-layer walls. They consist of a masonry carrying, insulating and covering layer. The construction of three-layer walls is time-consuming and more expensive than the other walls, but it allows to build solid, energy-saving and silent walls. Because three-layer walls are very massive and heavy, they are characterized by the best acoustic insulation. The use of an elevation layer, which is made, among others made of clinker brick or silicate bricks, makes the façade look solid and aesthetically pleasing.

MATERIALS FOR CONSTRUCTION OF MUROWANY WALLS

Most often ceramics, cellular concrete, silicates and expanded ceramics are used to build house walls. They can also be raised from styrofoam or formwork blocks.

Continuity of insulation on double-layer walls makes them the best in terms of elimination of thermal bridges - the insulation panels cover "colder" places.

Ceramics. Bricks and ceramic blocks are baked out of clay. They can be made as polished - then sawdust or wood fibers are added to their mass, which are burned during firing, leaving micro-pores filled with air to improve the thermal insulation properties of this material. Such ceramics are characterized by a lower heat transfer coefficient than traditional, which is why it is called warm ceramics.

Ceramics poryzowana, like traditional, accumulates heat very well. In order to obtain the best thermal insulation of the wall, hollow bricks or bricks should be positioned so that the long sides of their crevices (bores) are parallel to the face of the wall.Bricks and ceramic blocks also effectively isolate against noise. In order for the wall of this material to suppress the sounds as best as possible, the ceramics are bricked in such a way that the pattern of gaps in the material is perpendicular to the face of the wall.

The construction of external walls made of traditional bricks is an increasingly rare solution due to their small size and high labor consumption of building such walls. Roof blocks are most often used for the construction of load-bearing walls, which thanks to larger dimensions, and thus less wear per 1 m2 , allow for faster wall erection and lowering total bricklaying costs. Thanks to the use of hollow bricks with profiled sides, there is no need for vertical joints, which also speeds up construction works and reduces the expenditures needed for the construction of the wall. In addition, for a few years on the market you can find ceramic grounded hollow bricks - they are raised walls using a thin-layer adhesive mortar or a special mortar in the form of foam. This is a new trend in construction in our country, although it has been present in the Western markets for many years.

Cellular concrete. The basic components of aerated concrete are: quartz sand or ash, cement, lime and water. The porous structure is characteristic for aerated concrete, which it owes, among others good thermal insulation properties. Blocks are made of aerated concrete. Their important parameter is the bulk density - depending on it, the blocks are produced in several different varieties (with a density of 400, 500, 600, 700). The higher the density of this material, the greater the strength it characterizes, but at the same time has a lower thermal insulation. The 500 or 600 blocks, which are readily used for the construction of building walls, are characterized by high strength, but are not as warm as those characterized by lower strength of the 400 variety block. The latter two types of blocks are well suited for the construction of single-layer walls, where the thermal insulation of the material the wall is of great importance. Unfortunately, the warmer the cell block is, the generally worse it insulates acoustically. Cellular concrete is a vapor-permeable and easy-to-clean material - it can be cut and grinded in practically any shape. For this reason, cellular concrete blocks are readily used in the construction of arched walls. On the market, we find blocks cut with less accuracy (marked with the GPLM symbol), intended for bricklaying walls for a thick joint (ordinary mortar) and blocks cut on modern slicers (marked with the TLMA symbol), which are coated with thin-layer adhesive mortars. Blocks, as well as hollow bricks, can have shorter sides contoured on feathers and grooves, thanks to which they are bricked without having to fill mortar with vertical joints. Various blocks of various dimensions are available on the market, which allows you to make an optimal choice as to their thickness and length, so that masonry work can be carried out efficiently, without additional investment.

Hollow bricks are light and have the most contoured flanks to facilitate bricklaying

The producers offer finished lintels for building blocks

Silicates. They are distinguished by very good acoustic insulation, high thermal accumulation (heated slowly give away heat to the environment), non-flammability and high durability (you can build walls exposed to heavy loads, especially multi-storey buildings). They have a high heat conduction coefficient, which is why they are most often used for the construction of sandwich walls - insulated. Silicates have relatively small dimensions compared to other materials, they are also quite heavy, therefore the construction of walls with their participation is not one of the fastest, but good technical parameters eliminate these inconveniences and now silicates are willingly used in both industrial and residential as well as individual construction . You can find full and hollow silicate blocks on the market. Lighter hollow elements are usually selected for exterior walls - they are also slightly warmer than full blocks. Hollowing in silicones can be used to guide installation cables. In addition to natural elements in white color, silicate colored bricks are also produced. They are used to make the elevation layer of three-layer walls.

Keramzytobeton. The basic building blocks of this material are porous granules of foamed and sintered clay (called keramzyt) combined with cement and water. Expanded concrete is a material with good thermal insulation properties, it also accumulates heat (it warmly and slowly releases heat to the environment). It is a heavy material, and therefore effectively insulates against noise.

Styrofoam blocks. These are styrofoam fittings that are flooded with concrete. The fittings are made of two polystyrene boards joined by ribs. These boards can have different thicknesses, depending on the thermal insulation of the wall you want to achieve.The fittings have special locks that make them easy to combine and are made quickly. Shuttering blocks. They are usually made of aggregate concrete. These are fittings that are filled with concrete during the construction of the wall. They are usually used for the construction of external walls, which must be characterized by high durability.

FOR SOLDERING WALLS

How warm layered walls will be and how much heat will escape through them depends to a large extent on the thickness of the insulation layer. For the insulation of two- and three-layer walls, styrofoam and mineral wool are most commonly used.Investors are also more eager to reach for other thermal insulation materials. The standard thickness of insulation made of polystyrene or mineral wool is 12 cm , however, when building an energy-efficient house, you need to apply a layer of warming greater thickness - about 20 cm . The worse the thermal insulation shows the wall, the better it needs to be insulated. When choosing an insulating material, pay attention to its thermal conductivity coefficient lambda ( λ ) - the lower it is, the better. The use of a thermal insulation material with the lowest coefficient λ will allow to obtain adequate thermal insulation of the wall while maintaining the smallest thickness of insulation, and thus also the entire partition.

Mineral wool. It is a very good thermal, acoustic and anti-moisture insulation. It is a flexible material and - importantly - non-flammable, therefore its use increases fire resistance of the wall.

For insulation of walls, among others wool with disturbed fiber arrangement (thermal conductivity coefficient λ 0.037-0.040 W / (mK)). It is characterized by high elasticity and elasticity, thanks to which during assembly it can be easily adapted to the shape of the structure (eg to arched walls). Mineral wool boards covered with a glass veil (coefficient λ 0.034-0,039 W / (mK)) are used for insulating walls by the dry light method and three-layer walls. The glass veil protects the wool against moisture and prevents heat from insulating material.

Lamellar wool panels ( λ = from 0.040 to 0.042 W / (mK)) have fibers arranged perpendicular to the surface of the panel. It's a flexible and tear-resistant material. Thermal insulation of such wool, however, is slightly lower than other boards. The lamellar wool is usually used to insulate double-layer walls by the light wet method. You can also find wool boards consisting of two layers on the market ( λ approximately 0.038 W / (mK)). Their top layer is harder and the bottom is soft, thanks to which it adheres well to the wall.

Styrofoam. This material is lighter and easier to handle than wool. It is also more resistant to moisture, but not so resistant to fire. It also does not insulate acoustically as well as wool. It also has poorer vapor permeability. The thermal conductivity ratio λ of expanded polystyrene ranges from 0.031 to 0.044. The warmest is styrofoam with the addition of graphite (the so-called polystyrene with dots) - its coefficient λ is 0.031-0.033 W / (mK), while standard polystyrene boards have a coefficient of λ on the level from 0.038 to 0.042 W / (mK). There is a grooved polystyrene on the market with embossed parallel grooves for draining water generated during condensation.

EPS 50 polystyrene boards are the lightest and most vulnerable - they are used in three-layer walls and insulated with a light dry method. EPS 70 and EPS 80 expanded polystyrene boards are characterized by higher density and are usually used for insulation of double-layer walls by the light wet method.

Extruded polystyrene (XPS). This is the top shelf insulation. XPS is warm (its thermal conductivity coefficient λ is 0.027-0.036 W / (mK)), hard, resistant to water, and also low absorbability. Extruded polystyrene boards are dyed to a different color (depending on the manufacturer). They can be recognized by the XPS symbol. Because extruded polystyrene is relatively expensive, it is worth using it when you want to achieve the expected thermal insulation of the wall at its small thickness.

Perlite expanded. It is a glass granulate resulting from roasting at a very high temperature riolitowego volcanic glaze, which as a result of this process increases its volume up to 20 times. Perlit very well thermally and acoustically insulates. It is non-flammable, resistant to moisture and changing weather conditions. It is used to insulate partitions by filling the loose material between the double walls.

Polyurethane foam. It is a good thermal and acoustic insulation, which is most often used for warming skeletal walls. The insulation is applied by spraying from the inside before assembly of drywall. The polyurethane foam, when applied to the surface within a few seconds, increases its volume by more than 100 times, sealing all free spaces. As a result, thermal bridges in the wall are not formed.

Pollytag. It is sintered granules formed from fly ash, small amounts of coal dust and bentonite. It is characterized by an unfavorable thermal conductivity coefficient ( λ about 0,14 W / (mK)), therefore to obtain well insulated walls, it is necessary to make a thick layer of this insulation.

Cellulose fibers. This thermal insulation is made of recycled paper. It is characterized by a relatively low coefficient of heat transfer λ (from 0.039 to 0.042 W / (mK)), thanks to which it thermally isolates well. Cellulose fibers also effectively suppress sounds, are non-flammable and do not absorb moisture. They are most often used as thermal insulation in hard to reach places - fibers are blown in a special machine between structural elements.

TO FINISH THE FACADE

Any type of wall can be finished with plaster and painted over

Plasters. This is the most popular and the cheapest way of finishing one- and two-layer walls. They are also used for finishing the façade layer of three-layer walls, if it is made of the same material as the supporting wall. If the plaster is to be laid on the wall (it will be a finishing of a single-layer wall or the elevation layer of three-layer walls), the most common choice is traditional, thick plasters. Double-layer plasters are usually used for finishing the double-layer walls with the light wet method.

Traditional plasters after laying have a thickness of 2- 3 cm . They are inexpensive, designed for finishing all concrete and masonry walls. They are divided into two main groups - cement and cement-lime plasters. Cement-lime plasters are very popular, mainly due to the low price and easy availability. They are also characterized by high vapor permeability and durability.Their disadvantage is that they absorb water well and are not shrink resistant, which can lead to cracking of the plaster during bonding. After laying, they have a slightly rough texture.

Cement plasters are more watertight than cement-lime and resistant to mechanical damage, but they are more difficult to apply.Cement plaster quickly binds and hardens - if it is not applied correctly, it may crack later.

Thin-layer plasters are distinguished by richer colors and a larger variety of textures than traditional ones, they are also easier to make - they are applied with a layer thickness of 2-10 mm . However, this material is relatively expensive. Thin-layer plasters can be found on the market: mineral, acrylic, acrylic-silicone, silicone, silicate and silicate-silicone.

Mineral plasters are durable and resistant to weather conditions. They are also characterized by good water vapor permeability.They are available in a fairly limited number of colors, which is why they are often painted with vapor permeable paint. Mineral plasters, unfortunately, absorb rainwater, so they can quickly get dirty.

Acrylic plasters are the most flexible of thin-layer plasters (and therefore least exposed to cracks) and easy to stack (also at low temperatures). They are available in many colors, they can have strong, saturated colors that do not fade. They are also characterized by relatively low absorbability and steam permeability. It is worth choosing acrylic plasters with the addition of biocides, so that mushrooms and molds will not appear on them.

Acrylic-silicone plasters are a better version of acrylic plasters, to which silicone has been added. As a result, they are more vapor-permeable, resistant to atmospheric factors and contained in the air pollution.

Silicone plasters are distinguished by their low absorbability, resistance to dirt absorption and flexibility, which makes them suitable for installation even at low temperatures. They keep their intense color for many years. Unfortunately, they are exposed to fouling with algae and molds.

Silicate plasters are resistant to attack by mold or other microorganisms. It is difficult to arrange them, they can also absorb dirt, which is hard to remove later. They are colored in many colors.

Silicate silicone plasters are a more polished version of silicate plasters. They are very resistant to adverse weather conditions and growth of molds or algae. It is easy to arrange them too.

Stone cladding. They not only decorate the wall, but also constitute a good and long-lasting barrier against weather conditions and damage. Natural stone is usually used for finishing two-layer walls made with the light dry method and as an elevation layer for three-layer walls. Frequently, sandstones, granites and basalts are chosen for facade slabs. A stone is a heavy and expensive material, which is why it is usually used on a part of the façade and it is easily combined with brick, plaster or wood.

Ceramic claddings. The most popular among ceramic facade materials are clinker bricks, façade bricks and ceramic tiles.Clinker bricks are less absorbent than façade cladding, but also more resistant to frost, dirt and adverse weather conditions.Clinker brick is very durable. When it comes to purchase costs, it is more expensive than façade. Ceramic plates are mounted on a special grid. They are aesthetic, and the house finished with them takes on a modern character. Ceramic plates are available in a wide range of colors and in many sizes, are frost-resistant and easy to assemble, and at the same time lighter than stone slabs.

Wooden facing. The façade cladding made of wood can be used to cover all the walls of the house so that it looks truly rural, or finish it only with fragments of the facade, combining wood, eg with plaster or ceramics. For wooden siding, pine, spruce and larch boards are most commonly used. Foreign species such as red cedar wood, Siberian larch and Scandinavian spruce are also popular. The most resistant to adverse weather conditions is the facing made of exotic wood.

Termodrewno. This is an improved version of European wood species. It arises as a result of subjecting the wood to a thermal treatment, which aims to improve its properties. Thanks to this, a moisture-resistant material is created, with less absorption and better thermal insulation. Such wood also retains dimensional stability and is more resistant to fungal growth.

Unusual facade materials

WALLET WALLS

Walls with a lightweight skeleton construction are usually made of softwood (pine and spruce) class C24, chamber-dried, four-sided planed with rounded or chamfered edges. Quadruple planing of wood ensures not only dimensional accuracy, but also fire resistance of the structure and provides protection against pests. The wood moisture content for frame walls can not exceed 19% for casements and 23% if they are not covered. Wall elements that have direct contact with concrete, walls, soil or water require obligatory impregnation and the use of horizontal damp insulation. The construction of the skeletal walls is made of poles and horizontal elements - eg foundations, caps - and a structural plating that performs the function of stiffening.

The outer walls are covered with moisture-resistant wood-based boards - OSB / 3, MDF, V-100 chipboard or waterproof plywood.

On the inside of the wall it is necessary to use a vapor barrier, which task is to regulate the flow rate of water vapor through the partition. Polyethylene foils are used as a vapor barrier. In order for the foil to protect the wall construction and insulating material against moisture, it must be tightly laid over the entire wall.

When constructing skeletal walls, it is also necessary to wind-proof, which protects the wall from the outside against the inflow of cool air and moisture.