Build Me Now!: Insulation of walls

Everyone knows that it is worth living in a warm home. The investor joining the construction can choose the technology that meets that expectation. However, even with an old house, you can improve his comfort. Just carry out the so-calledThermomodernization, one of the elements of which is the insulation of external walls.

The base of the building is insulated with non-absorbent boards made of expanded polystyrene: 1 - polystyrene, 2 - plaster, 3 - plinth, 4 - polystyrene, 5 - concrete band, 6 - gravel, 7 - indigenous soil, 8 - external wall, 9 - ceiling , 10 - basement wall.

The essence of isolation

Thermal insulation consists in placing a layer of thermal insulation on them, mainly from mineral wool or polystyrene, and covering it with façade material. It is most often a thin-layer plaster. Thermal insulation of both materials is similar, however their properties are different. A feature of mineral wool, which must necessarily be noted, is that the moisture loses its insulating properties. On the other hand, it is a material that allows drainage of the water contained in the wall to the outside. For this reason, mineral wool can only be covered with mineral or silicone plaster with high vapor permeability. Only then will the insulation be prevented from moisture due to the condensation of water vapor or moisture in the wall. The opposite is with styrofoam, which does not absorb water. It is possible to use plasters impermeable to water vapor. Some manufacturers offer special types of expanded polystyrene, for example for insulating walls built of vapor barrier materials. This is important information for people who want to warm up an old house. Normal styrofoam does not let any air in at all, which can cause dampness of rooms with inoperative gravitational ventilation.

In places heavily loaded and exposed to moisture, XPS extruded polystyrene can be used. The boards are hardened and non-absorbable, and they are used primarily to isolate basement areas of buildings and cellar walls. They are produced in thicknesses from 2 to 10 cm . National building regulations allow the use of thermal insulation polystyrene boards to insulate exterior walls of buildings up to 25 meters above ground level. In multi-storey buildings higher than 25 meters and in wooden houses - due to the increased fire hazard, it is recommended to use mineral wool. When starting to insulate a house, first determine the thickness of the insulation layer. This should be done by the constructor for a particular building, and the heat transfer coefficient U can not be higher than the U-value allowed, which is 0.3 W / m2K. Currently, the method of wall insulation can also calculate the energy auditor. The thermal insulation process consists of three main stages: substrate preparation, insulation fixation and façade coating.

In old houses, lack of insulation often leads to irreparable damage.

Is it worth to insulate the walls?

Definitely yes.

This is particularly important for old buildings with insulated or insulated walls. The freezing, non-insulated walls are exposed to destruction, while in the interiors may appear permanent moisture and consequently the fungus. In extreme cases, neglecting the insulation and thermo-modernization of a building can lead to its destruction. In the case of newly erected houses, the appropriate parameters of the heat transfer coefficient of walls are usually maintained. Single-layer walls erected with materials of appropriate parameters meet the requirements of currently applicable in Poland regulations in the field of thermal insulation of buildings. However, in an insulated house, thermal comfort is higher due to the high thermal resistance of the insulating material, several times the thermal resistance of a single-layer structural wall. Supporters of single-layer walls are often accused of the fact that the insulated walls do not pass the water vapor sufficiently and can not "breathe". This is not true, because you can easily choose products that have a vapor permeability that is even larger than walls made of ceramic bricks. Of course, the most important reason why buildings are warming is to reduce operating costs, in other words expenses for heating. Heating costs for a well-insulated building in winter are lower by up to several dozen percent compared to the heating costs of a non-thermal facility. However, do not insulate your home on your own. In the case of newly erected structures with laminar walls, the thermal insulation parameters are described in the architectural design. However, if we want to insulate an existing house, we should order a insulation project. Insulation thickness must be calculated based on the parameters of a particular building, with particular emphasis on heat demand, and the cost of works should be paid in a very short time. Otherwise, it will simply be unprofitable. The insulation systems available on the market meet standard requirements. When calculating system parameters, typical coefficients are used. The materials are selected so that the insulation of a standard house is effective and cost-effective, but most often it is possible to choose the thickness of the thermal insulation material offered. Although we are writing here only about thermal insulation of the building, it is worth mentioning that the thermo-modernization project should also take into account the modernization of the central heating installation, and it is certainly necessary for the developer to indicate solutions for the implementation of efficient ventilation. One of the effects of building insulation is the limitation of air exchange caused by the sealing of walls and wall connections with windows and doors. If traditional gravitational ventilation remains, it will not fulfill its task. Unfortunately, moisture and mold may appear in the interior quickly. If the insulation designer does not present such solutions, then you can use the detailed guidelines - usually they are drawings of details - which most often have insulation system manufacturers.

Any damage and greater unevenness of the plaster must be thoroughly filled with leveling mortar.

The most important in warming

We write a lot about building insulation technologies, we also touch this topic in our folders. Therefore, at this point, we want to pay attention to particularly important activities related to thermal insulation. Inaccurate performance or omission may have a significant impact on the durability of the work carried out. Before starting the insulation works it is necessary to dismantle all gutters and downpipes. They will interfere with your work and may be destroyed.

Subsoil

Before attempting to insulate the walls, an adhesion test of the old coat, both plastering and painting, should be made. You can check it by cutting it with a cross knife, sticking the adhesive tape and then breaking it. If a part of the coating breaks off, it should be considered poorly adhesive. Another way is to gently tapping uncertain places with a hammer. A hollow sound indicates a weak and loose ground. It is necessary to plaster or remove paint from weakened places. All cavities and places from which the plaster has been removed are filled with plaster mortar or leveling leveling mortar. Inequalities above 1 cm are also filled with leveling mortar or renovation and leveling mortar. Before proper thermal insulation work is carried out, the mortar must firmly bond. The day before the insulation starts, wash the surface of the walls with water under pressure to remove dust and dust. Absorbent substrates are usually primed with a preparation increasing adhesion of adhesive mortar.

The profile of the plinth must be perfectly leveled and carefully screwed to the wall.

Plinth strip

The first stage of insulation works, of course, after repairing the substrate is fixing a metal plinth profile on the wall to be insulated, on which the first row of insulating material will be based. After marking the wall on the surface, at a height of approx.40 cm above the ground level, a perfectly horizontal line, the profile is fixed with dowels.

Joints of insulation boards must be sanded evenly. The mineral wool is additionally fastened with dowels in the number of 6 pcs / m2 of the wall.

Between the sections of the profiles, approximately 3-millimeter spacing is left to allow their dimensions to change as a result of heating from the sun.

Thermal isolation

The first row of insulation is based on the profile, while the boards in subsequent rows are glued with a 1/3 shift.

If, after gluing, the panel plane will not be even, it should be gently sanded with a special trowel or sandpaper applied to the plastering plaster, but not earlier than after 3 days from gluing the insulation.

Fragments of the net around the jambs must be slightly stretched so that folds do not form on it. Adhesive mortar must be so blurred that they do not remain lost, as they will be visible on the plaster.

Strengthening corners

The corners of the building and the window and door openings are particularly vulnerable to mechanical damage and wind.Strengthening the area of window openings consists in gluing additional pieces of fiberglass reinforcing fabric to the wall already reinforced. Fragments about 20x35 cm are placed at a 45º angle near each corner.

Pieces of fabric are also stuck in the corners at the junction of the vertical jambs with the door lintel.

The reinforcing mesh can not be cut at the edge of a wall corner. It is necessary to roll it over to an adjacent wall at approx. 15 cm . Also, roll the net on the window and door jambs.

In areas where there are several layers of reinforcing mesh, the mortar must be tightened to prevent the thickening from remaining on the plaster later. However, it is not allowed to reveal the net. Also, it is not possible to stick fibers out of the mortar layer at any point.

Convex corners and edges at door openings are additionally reinforced with steel corner metal profiles. To their vertical edges, steel mesh strips are welded, which must be embedded in the mortar.

Steel profiles with mesh and right-angled putties with smooth edges are used for making corners.

Corners must be particularly evenly spaced, because they are an eye-catching element of the building's body. Their inaccurate work will, unfortunately, be clearly visible. In order to facilitate the work, you can use a special steel spatula, bent at right angles.

It is also good to check the corner line by attaching a medium thickness at the top and bottom of the wall. Then all the plaster cavities in this place will be clearly visible. The corners are reinforced after the reinforcing layer made of glass fiber mesh on the entire insulated surface.

A drip should be placed on the lintel, whose task is to drain rainwater from the connection of the window or door with the jamb.

lintel

Improper or inaccurate treatment of window and door lintels may result in damage to the insulation and moisture of the walls.The water flowing down the façade over the facade lays on the lower face of the lintel, from where it can get into the gaps at the connection of the insulation with the window or door frame. This can be avoided by using the so-called drip. The easiest way is to put a ready profiled strip in this place, but you can also shape the projection in the lintel or cut the plaster in the shape of the letter "V". The diaphragm strip should stand out from the face of the wall approx. 4 cm .

Thanks to profiling the edge of the lintel, the rainwater flowing down the façade drips directly onto the window sill.

Plastering

Work on one wall should be carried out without breaks, so that the structure and color of the plaster are the same. The application of the plaster starts from the top of the wall and continues with horizontal stripes of the height resulting from the spacing of the scaffolding platforms. Most often they are about 2 m . In one-storey buildings, you can first plaster the window strip, then between the windows and finally under them. It is not allowed to plaster in the rain, strong wind or high insolation of the façade. If this can not be avoided, special shields must be used to reduce the impact of weather conditions. Currently, plaster with texture obtained due to the addition of aggregates of various grain sizes are fashionable. The plaster is rubbed on the thickness of the aggregate; the larger the invoice is. One of the most popular plasters, so-called the lamb is applied and pulled with a plastic trowel. Then it fades, remembering to move the trowel with the same movements, so that there are no differences in the texture of the plaster.

Kreisel advises

When making thermal insulation, mistakes are often made. The most visible effect is the uneven surface of the façade.

Good start. Correct mounting of the plinth profile determines the exact leveling of the insulation boards to be cleaned.

Correct installation. Insulation panels fixed by the band-point method are glued to the ground for min. 40% of their area (perimeter band with a width of a few centimeters and 2-6 patches with a hand diameter, their arrangement must correspond to a later arrangement of pins). The lack of peripheral band can cause the plates to be pressed - their surface will become uneven.The boards must be glued in a staggered way, and in the corners of the building they should interlock.

Final alignment. Any unevenness should be ground off, because it can not be "lost" in the reinforcing layer or during plastering (together they have only 4-6 mm ).

Each of the next stages of insulation works also has its implementing rules. It is also necessary to observe the minimum time between consecutive stages of works, because it affects the durability of a given thermal insulation system. Do not forget about the use of only one manufacturer's thermal insulation system. Using ingredients from different manufacturers most often causes later problems, which everyone wants to avoid.

Monday, January 14, 2019

Insulation of walls