It turns out that the method of bonding is extremely important and may affect the durability of plates or have an impact on safety during a fire. Check why insulation boards should be mount with the method of apply 3 equally spaced adhesive mortar dabs through the centre line of the insulation board and a strip around the edge.
STABILITY AND UNDEFORMABILITY OF BOARDS Adhesive applied around the edge creates a kind of a 'frame', which provides a high stability and undeformability of plates. That kind of bonding also ensures a significant thermal work and protection against the wind. Moreover, it is the most effective way of transfering the weight of insulation to the wall. Randomly distributed patches, instead of a strip of adhesive around the edges, may cause deformation or even the movement of the material, resulting in the crackings in the surface layers of insulation. Let's see the consequences of improper bonding below:
PREVENTING THE AIR MOVEMENT BETWEEN LAYERS Another important function of the strip of adhesives around the edges of insulation boards, is to prevent the air movement between the layers. When insulation is applied correctly, layer between the wall and the thermal insulation is not ventilated - although there is still a misconception about this.
To illustrate the problem, assume that: 'gravity moves the air between the insulation and the wall'. To ensure the proper air circulation, the gaps are left (often with the special vent) between the wall and the insulation - at the bottom and top. The air begins to flow causing a chimney effect. What happens if the temperature outside is - 15 ° C? Well, then the function of the insulation suddenly disappears and in addition to cooling the walls and air exhaust heat, we also have to deal with the condensation of water vapour in the area of the outer wall, which we cannot even see.
SAFETY DURING FIRE If the thermal insulation is applied without a strip of adhesive around the edges of boards - there is another very important problem - the loss of thermal insulation properties, associated with the non-proliferation of fire. Randomly distributed patches of adhesive create a space, between the substrate and the insulation, that accelerates the spread of flames in the event of fire (chimney draft caused by the difference in the density of cold and hot air). Bonding by using 3 equally spaced adhesive mortar dabs through the centre line of the insulation board and a strip around the edge prevents the formation of such chimney drafts.