Internal Insulation of Historic Buildings - Desirable but Risky

[Music] today historic buildings built prior to 1945 make up 30% of the European building stock many of these buildings have great architectural and cultural value especially the detailing of facades is the architectural character heating these historic buildings accounts for a significant part of the energy consumption in Europe it's expensive and results in a large co2 emission insulation of these buildings will reduce heating expenses and lower the co2 emission a building can be insulated externally or internally external insulation covers the facade and hides the architectural details technically this is a good solution if the building is insulated internally the historic details of the facade are preserved but technically this is a risky solution why is internal insulation risky internal insulation means more severe thermal bridges one of the results is that beam ends in the facade become colder this can result in the deterioration of wooden beam ends in the facade but it's not the only challenge without internal insulation the original wall will have the room temperature on the inner surface if the wall is insulated internally the inner side of the existing wall will be cold when it's cold outside as the heat flow through the wall is reduced a cold inner surface of the original wall can cause problems if moisture from the warm moist indoor air passes through the internal insulation and condensates on the wall if there's a high moisture level somewhere typically between the existing wall and the internal insulation there's also a risk of mold growth one way of managing the problem is to install a separate vapor barrier that prevents the warm moist indoor air from penetrating the insulation another is to install an insulation material that in itself is vapor tight yet another way of managing the problem is to use an insulation material that's open for vapor diffusion and enables capillary suction if the inner surface of the existing wall gets wet the moisture will be transported through the insulation material to the indoor air a vapor barrier should be avoided in this case a reduced heat flow through the wall also presents other challenges a decreasing heat flow causes the original wall to grow cold when the weather outside is cold this means that it will take longer for the wall to dry if it gets wet this can cause spalling of the facade when it's freezing outside and gradually degrade the wall if the wall is often wet for long periods of time algae growth may appear on the facade internal insulation isn't an easy task rebuild is an EU research project that develops guidelines on how to install internal thermal insulation in historic buildings in a moisture safe way the amount of energy used for heating in the historic building mass can be reduced by 15 to 20 percent if you want to know more about rebuild please visit us at rebuild dot EU you can sign up for our newsletter and follow us on Twitter and LinkedIn

Channel: RIBuild Project

Views: 39,861

Rating: 4.8984771 out of 5

Keywords: internal insulation, RIBuild, historic buildings, insulation, energy saving, culture

Id: HeH1B1mmD48

Length: 4min 28sec (268 seconds)

Published: Mon Jan 21 2019