Concrete Elements

Heat Insulation of Concrete Elements

The heat insulation of concrete elements such as columns, beems and senaz are applied with the 3 methods of heat insulation of stonework, internal, exterior and in the gap, is however important to focus only in the case where it is combined with heat insulation of double stonework with gap. The columns, beems and senaz have to be insulated for the prevention of thermal bridges, because they are all constructed from armed concrete which has 4 times larger thermal losses compared to bricks. In our days where the density of armament increases continuously and the surfaces of concrete, as percentage of the total surface of stonework, also are increased it is even more important. Since the steel of armament as metal has 25 times more losses than concrete and in consequence 100 times more compared to the brick this means that the thickness of heat insulation in concrete elements should be bigger than that of gap between the bricks.

Constructional according to the methodology that is used the heat insulation in concrete elements enters in the wooden formwork of the manufacture before concrete is purred. In practice due to various difficulties it rarely exceeds thickness bigger than 5cm while usually is placed 3cm despite the fact that this does not cover the regulation of Energy Efficiency of Buildings that is valid from 1/10/10, and the Regulation of Heat Insulation of 1979. The problem remains even if the heat insulation in concrete elements is placed after the concrete purring and before the coats with glue and plugs for mechanic fixing. The problem is that in order for the bricks to be at the exterior side at the same surface with the heat insulation of concrete elements, if the thickness of heat insulation exceeds 5cm, the brick of exterior stonework obligatory abuts at a big percentage on the insulation, which creates problems of stability of the exterior layer of double wall.

This problem of course is solved with the manufacture of single stonework with 18 cm brick and in condition that drawn frames are not placed.

At the same time, placing insulation in the wooden formwork complicates vibration, and does not allow control after the concrete purring for “nests” from the exterior side, which means points in which the armament was not covered by the cement and is inactive. The nests are mistakes in concrete purring that should be repaired in order to avoid corrosion in the armament and risk the static sufficiency of the building

In heat insulation of concrete elements is recommended the use of Expanded Polystyrene with Graphite ΝΕOCOAT BT EPS 150, ISOPLAK BT EPS 150, ISOPOR EPS 150 and ISOCOAT BT EPS 80 in the correct thickness according to the regulation of Energy Efficiency of Buildings.