Insulation

Heating accounts for up to 70% of the energy bill in buildings and yet without adequate insulation much of this energy is lost or wasted. So insulation saves money and reduces the amount of carbon dioxide produced.

 

Insulation will also act as a sound absorber or barrier to keep noise levels down.

 

Heat flows naturally from a warmer to a cooler space. The larger the temperature difference the more quickly the heat flows. Insulating ceilings, walls and floors decrease this heat flow or heat loss by providing an effective resistance to the flow of heat.

 

The effectiveness of insulation is rated by the U-value. The U-value is the measure of the rate at which heat is lost through a material. As it is the measure of the heat loss, the lower the U-value the better.

 

The targeted elemental U-value (W/m2k) in the latest building regulations are as follows:-

Wall – 0.22.

Floors – 0.20

Roof Ceilings – 0.15

Roof Slope – 0.18

 

Insulation evenly distributed over all the element (floors, walls and roof) produces better results than additional insulation applied to only one element. Good workmanship on the installation and attention to detail are most important when insulating a building to avoid thermal bridging.

 

Thermal bridges are points in the building envelope that allow heat conduction to occur. Since heat flows through the path of least resistance, thermal bridges can contribute to poor energy performance. This is recognised in the Irish building regulations Part L.

 

Insulation comes in many forms but is usually supplied in four types – batts, rolls, loose fill and rigid foam boards. Each type is made to fit a different part of the house. Batts are made to fit between the studs in the wall or between joists of the ceiling or floors. Batts are usually made of fiber glass or rock wool. Rolls are usually made of fiber glass and are laid over the floor in the attic. Rigid foam boards are made of extruded polystyrene or expanded polystyrene or other materials. These are light weight board and are used in wall and floor insulation.