External Wall Insulation protects the structure of a home
The external cladding of buildings plays a crucial role in architecture. It also has the important function of protection against weathering. The facades of buildings therefore must reconcile aesthetic requirements with needs related to the durability of the structure. This must take place in the face of numerous types of wear and tear: mechanical, chemical, thermal, and hygrometric not to mention human activity
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The functions of the External Wall Insulation (ETICS) system include saving money with thermal insulation, reduction of mould and protecting the facade from weathering. External insulation keeps the whole of the original wall warm and dry, minimising the risk of condensation, and keeping the wall in good shape for longer.
There are two routes by which External Wall Insulation help preserve the facade. These are temperature cycling and moisture. These correspond broadly to two key elements in the External Insulation system, the finish and the insulant.
External Insulation keeps the building dry
In Ireland’s maritime climate the main cause of deterioration of the facade is from the infiltration of rainwater into the building walls. The original reason to build standard cavity walls was to protect the inside from driving rain. Any moisture which passed through the external leaf of block work would drop into the cavity and so not penetrate the inner leaf.
As a part of an External Insulation system you get a polymer enhanced external finish. These modern finishes are actually waterproof, which means that you no longer need the damp cavity. Not having water in the block work means less damage from frost action.
The other source of water in a wall is from inside the dwelling. In 1998, Dr Hartwig Künzel of the Fraunhofer Institute in Germany published a paper on the moisture content in different walls types. Künzel concluded that external insulation leads to the drying of the wall, with the speed of drying depending on the vapour permeability of the insulation system used. He found that internal insulation, on the other hand, causes water content in the wall to rise due to the temperature drop in the wall. The presence of water in the wall will inevitably lead to deterioration in the structure as well as mould growth.
Thermal Fatigue and External Wall Insulation
External Insulation keeps the fabric of the building at a steady temperature, this reduces the strain on the building from expanding and contracting as it heats and cools. By mounting the insulant on the outside of the building (External Insulation) the masonry core of the building is protected from changes in ambient temperatures. In a paper entitled “Transient analysis of an external building cladding” this very point was investigated by Balocco et al. The thermal and mechanical performances of external cladding, applied to a traditional wall, largely used in existing buildings, were investigated by a transient analysis. Result comparison with the thermal performances obtained by simulating the wall without the insulation system showed that external insulation is particularly effective in reducing cooling and heating loads and can also guarantee indoor thermal comfort. Fatigue stresses of the external cladding, investigated by ANSYS simulation, showed that continuous change of the loads over time with limited cyclic stress can cause deterioration of materials.
Contact us now to learn how your home can be protected by External Wall Insulation.