Characteristic of the system

• LAKMA TERM ST - the insulating layer is composed of foamed polystyrene boards
• LAKMA TERM WM - the insulating layer is composed of mineral wool boards

Insulating system LAKMA TERM WM is a variety of "light wet" technology. It consists in fixing from the external side multi-layer insulation-elevation system, in which thermal insulation layer are mineral wool boards, and an elevation layer is thin plaster applied on prepared before layer reinforced with glass cloth.

• perfect thermoinsultion properties guarantying thermal stability of insulated rooms,
• high permeability of water vapour,
• acoustic insulation of walls,
• incombustibility and fire resistance,
• health and environmental friendly materials.

Thermal insulation system LAKMA TERM WM is used in already existing as well as newly built buildings in order to assure appropriate heat comfort at the same time giving proper aesthetics and elevation durability.

• Mineral wool boards - guarantee right thermal insulation.
• Adhesive mortar + wall plugs fixing wool to walls - guarantee construction stability of thermal insulation system.
• Reinforcement fabric of glass fibre - limits thermal deformation of protective layer, protects from cracks and increases resistance to mechanical damages.
• Plaster - is a finishing of the surface of insulating system, protects it from influence of atmospheric factors and increases its resistance to blows, owing to well chosen colouring and texture it gives the elevation of a building an aesthetic look.

• reduces costs of heating and thermal energy consumption,
• liquidates thermal bridges in insulated buildings,
• lowers costs of new building construction by decreasing thickness of walls and assembly of smaller radiators and central heating furnace,
• enables any spatial formation of elevation by application of different thickness of mineral wool,
• eliminates occurrence of water vapour condensation on walls, prevents from creating moulds and fungi on walls,
• increases acoustic insulation of walls , which is particularly desired in buildings which stand near places with high intensity of noise,
• eliminates formation of scratches on buildings caused by thermal stress, because all construction elements of walls has similar temperature,
• it keeps maximum heat and minimal cost of heating in winter, and in summer creates pleasant microclimate,
• protection of the environment by reduction of emission of sulphur dioxide resulting from decrease of consumption of energy carriers,
• it extends life of buildings and increases their resistance to mechanical damages and influence of atmospheric factors owing to application of high quality silicate, silicate-silicone and mineral plasters.

• when the temperature of the base and air is lower than +5 C and higher than +25 C,
• during precipitation and high insolation,
• during strong wind.

• the part of elevation separated with edges should be plastered in one realization step with plaster from the same production batch,
• freshly applied plaster in period of its drying on a wall should be protected from unfavourable atmospheric conditions, mainly rain and high insolation with scaffolding- shield network.

Technology of lagging works with application of LAKMA TERM WM insulating systems

Before approaching to insulating of a building it is necessary to prepare materials, tools and equipment according to specificity given in a technical project, and also check if materials correspond with standards and have quality certificates. Checking quality of materials is an obligation of a contractor, because he is responsible for right realization of insulation. Before beginning lagging it is necessary for the time of works to disassemble all elements which make difficult right adhesion of foamed polystyrene boards, and also disassemble flashing, downpipes, switches. Lagging a building will cause thickening of walls, what will create a necessity to increase reaches of above-mentioned elements.

2. Bases and their preparation

Bases: old and new plaster with carrying surface and stable structure, solid and cellular brick, concrete, hollow blocks and wall blocks of light concrete, porous concrete. Checking and preparing the surface of walls - before beginning to insulate walls it is necessary to check precisely its surface and try to glue insulation layer. In order to make a test the wall must be cleaned of dust, spalled thin layers and glue in different places 8-10 samples of mineral wool of size 10 x 10 cm. For gluing samples we use adhesive mortar SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 applying it on whole surfaces of sample, without fibres formed during cutting, on thickness of 1 cm and pressing it strongly to the wall. After 4-7 days rip off the glued samples of mineral wool. Small unevenness of surface should be levelled with levelling mortar. The places, where we apply the levelling mortar should be heavily moistened with water before. The next work, in order to prepare the base well, is washing whole lagged surface with water. It can be used with a use of water under pressure or with a rise brush. Owing to this work we remove dirt from walls and rests of spalling old materials. In case of absorbable and dusty bases it is necessary to coat them with primer coating preparation AKRYL G. Insulating material can be glued only after complete drying of AKRYL G.

3. Checking efficiency of mechanical fixing

In case of mechanical fixing of mineral wool to the base it is necessary to check on 4-6 samples the force tearing out joints from a base prepared for lagging. The action is made according to rules specified in BRI (Building Research Institute) certificates, admitting the joints to use in building.

4. Assembly of a starting profile

After establishing the height of a plinth (in case of buildings with cellars the height is minimum 20 cm below lower plane of floor over cellar), we mark a line with a rope coloured with chalk. We fix the starting profile using 3 pieces of wall plugs for every running meter. The starting profile should be always fixed to a wall in last holes on both sides of the profile. Unevenness of walls should be levelled with spacers. In corners the profile is cut at a 45 degree angle.

5. Preparation of dry adhesive mortar

SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 is destined for gluing both foamed polystyrene boards and boards of mineral wool and for realization of reinforcement layer for both insulators. Adhesive mortar SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 should be poured into a bucket which consist prepared before water and mix it with a mixing paddle on low revolutions. After receiving homogenous consistence we put aside the bucket for 5-10 minutes and mix again. The quantity of water needed for making the mortar is given on the package of the product. The preparation of adhesive SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 should be done in temperature from +5 C to +25 C.

6. Adhesion of mineral wool boards.

Mineral wool boards should be glued during rainless weather, when the air temperature is not lower than 5 C. The prepared adhesive mortar should be applied on mineral wool board in two steps.

The first step is thin luting with adhesive on whole surface of the board. Next with a metal toothed long float with teeth size of about 10 x10 mm, the right layer of adhesive mortar is applied on whole surface of the board. The usage of adhesive SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 is given on the package. After applying adhesive on the board it is necessary to put it immediately in the right place for it and press it by blowing with long float until you get levelled plane with adjacent boards. The boards should be pressed together overcoming elasticity of boards, which subject to little squeeze. This activity enables arranging boards with smaller gaps.

If the adhesive mortar squeeze in outside outline of the board, it is necessary to remove it. It is unacceptable to squeeze already glued mineral wool boards for a second time, or move them after a few minutes. In case of wrong adhesion of mineral wool board, it is necessary to rip it off, remove the adhesive mass from the wall, apply it again on board and press it to the wall surface. The boards are glued closely one to another starting from board lath up to eaves keeping staggered joints. Gluing mineral wool boards in region of holes corners one should cut them, so the horizontal and vertical joints among boards do not contact (not fall out) on holes edges. Insulating walls made of prefabricated products- mineral wool boards should be arranged in such way, so that the joints among the boards do not cover the connections of prefabricates. The width of vertical and horizontal gaps among mineral wool boards should not be larger than 2 mm. If it happens that the gap is wider, it is not allowed to fill it with adhesive mortar. The best solution is to fill it with a mineral wool stripe of the right width.

7. Mechanical fixing of mineral wool boards.

Using mechanical connector one should restrict a condition to use only those, which has BRI certificate admitting to use in construction. Every time the projector defines precise quantity of connectors on 1m2 of insulation, their length and type in insulating project. When there is no project it is accepted:

• for lamella boards 4 pieces on 1 m2 of insulated surfaces
• for lamella boards 4-7 pieces on 1 m2 of insulated surfaces in side area
• for regular boards 4-8 pieces on 1 m2 of insulated surfaces.

Connectors with large pressure collar are used for lamella boards. To fix boards of mineral wool one should use only mechanical connectors with steel mandrel. For walls of buildings higher than 20 m it is obligatory to use only mechanical connectors - irrespectively if the base have the required resistance or not. Even if resistance of the base of building walls lower than 20 m high is right, but they are located in areas of strong wind and air currents activity effecting insulated buildings one should use additional mechanical connectors. The head correctly set plastic plugs should face with the surface of mineral wool board. Excess hollow of a plate in wool can cause tearing its structure and weaken its structure.

8. Realization of reinforcement layer on foamed polystyrene

Realization of reinforcement layer on mineral wool can be started not sooner than after 3 days from the moment of adhesion of wool, during rainless weather and temperature not lower than 5 C and higher than 25 C. If decrease of temperatures below 0 C is forecasted during 24 h, it is not allowed to glue reinforcement net even, if temperature during work time is higher than 5 C. If it is necessary to perform insulation of mineral wool late autumn, when can occur high humidity of air and temperature falls, one should absolutely shield the insulating system with a reinforcement layer, and coat it. It is unacceptable to glue boards and leave them on the wall without cover, because there is a possibility of penetration of water through the layer of adhesive to the board. Realized reinforcement layer should be protected from strong wind and during occurrence of large insolation - even, if the temperature doesn't exceed +25 C - considering a possibility of excess drying during binding mortar. The reinforcement layer is made of SYNTEKOL SW/ SYNTEKOL Q4/ SYNTEKOL PSW/ POROLIT Q4 adhesive mortar and fused in it glass fibre.

• set corner bead with a net on corners of building wall and on corners of window and door holes,
• reinforce all holes corners by adhesion of net in size 20 cm to 35 cm - gluing it at a 45 degree angle.

We start realization of reinforcement layer from corners of windows and doors, reveal of holes and from expansion joints. Prepared adhesive mortar is applied on mineral wool boards with continuous layer 5-6 mm thick and 1 m wide. The action is made with smooth side of a long float of stainless steel. We start applying adhesive in a building corner. Next we brush the adhesive with toothed side of the float, teeth size 10 x 10 mm. After applying adhesive mortar it is necessary to fuse the net immediately using smooth side of the float. It is necessary to remember that external strip of the net should be pulled out the corner for width of 15 cm, and then bent and plunged in glue. After plunging the first strip of net we analogically act on the next meter of the wall. It is necessary to strictly obey the rule of applying the net on plead not smaller than 10 cm in vertical and horizon. The thickness of layer reinforced with one layer of net should have 3 to 5 mm. It is unacceptable to glue the reinforcement cloth in a way, that it is applied on wool which is not covered with adhesive mass, which is then once applied on the cloth. The parts of building which are particularly exposed to mechanical damages i.e. ground floor walls to height 2 m over ground should be reinforced with double net layer. The reinforcement layer should be very precisely luted avoiding creating any unevenness or folds. All shortcomings on its surfaces should be luted, and then in the moment of drying of the adhesive ground it with a sponge for gypsum plasters after previously having sprayed it with a sprinkle. The more carefully we prepare the reinforcement layer the better effect we will get after applying thin-layer stucco.

Realization of stucco

• AKRYL P - under acrylic plasters with a light filler (POROLIT )
• TYNKSILGRUNT - under silicate and silicate-silicone plasters (TYNKSIL; TYNKSIL S)
• MINERALGRUNT - under mineral plasters (MINERALTYNK)

Primer coat AKRYL P and TYNKSILGRUNT should be coloured in colours close to plaster colours. Primer coating is made after 3 days from finishing of realization of reinforcement layer, in order to bind fully the adhesive and increase adhesion to thin-layer plasters.

AKRYL P, TYNKSILGRUNT, and MINERALGRUNT are applied on wall surfaces using a brush or spray. When primer coat dries it is possible to start performing stucco. Acrylic, silicate and silicate-silicone plaster before using should be precisely mixed with low-speed drill to receive homogenous mass. Mineral-polymer plaster should be poured into a bucket together with prepared before required amount of water (the quantity given on a bag) and precisely mixed to get homogenous mass. After 5 minutes the plaster should be mixed again. The very important thing during plaster works is realization of all works connected with it in right atmospheric conditions. During realization and drying of plaster air temperature should be in range from +5C to +25 C. The plastered surfaces should not be exposed to direct sun activity and wind, because those factor speed up considerably plaster drying what significantly makes difficult receiving proper texture of plaster. The plaster directly after applying should be protected from rainfall to the moment of its preliminary hardening.

Applying plaster with traditional method (trowel, long float)

Plaster mass is applied on smooth long float of stainless steel with a use of trapezium trowel, after that it is pulled on a wall on a grain thickness. Excess of plaster should be removed with a use of smooth steel float gently pressing it to the wall. The plaster collected from the wall after mixing is ready for a new use. It is very important to apply plaster on such surface of a wall that it is possible to texture it correctly and connect it with next part of applied plaster when it is wet. The size of every part of applied plaster depends mostly on contractors' practice, weather conditions, and also absorbability of the base. After collecting excess of plaster we approach to give it right texture. We do the work with plastic plane float. We rub the plaster of a lamb structure by making circular movements. The plaster of woodworm structure is rubbed by making movements from top to bottom, horizontal or circular, what cause receiving respectively vertical, horizontal or irregular scratches.

Applying plaster with spray method with using plaster aggregate LAKMA

Applying plaster with spray method is made with special plaster aggregates offered by LAKMA company. With the spray method we can plaster only plasters with "lamb" structure, a thickness of aggregate: 1,0 mm; 1,5 mm; 2,0 mm; 2,5 mm. After appropriate adjusting pressure in compressor and diluting plaster to right consistence, we start assembling a gun nozzle. The diameter of a nozzle depends on thickness of aggregate in plaster. We fill the reservoir of a gun with plaster mass and pull the trigger. Mass flow should be sprayed perpendicularly to wall surface on a distance of 30-45 cm. The gun should be led uniform motion on whole fragment of the wall, which is a separate part of elevation. More information on spraying plaster work topic you will find in separate guidebook "Spray Systems".

Realization of combination of different colours, plaster types

A paper self-adhesive tape is stuck in a place of planned connection of two plasters. The plaster is applied with little overlap on the tape. After rubbing the plaster, when it is still wet, the stuck before tape is ripped off. After plaster drying, on its edge the tape is stuck again. It should be precisely pressed to the plasters surface. Afterwards the plaster is put on the second side of the tape. It is necessary to pay attention not to make the plaster go under the tape. After rubbing of plaster the tape is ripped off the wall.