Includes papers on pitched roofs, flat roofs, wall construction, window and door joints, and weathertightness and water penetration of buildings. The focus is mainly on water penetration but air infiltration and ventilation are also discussed.
A major cooperative study of the effect of ventilation of timber flat (cold) roofs on combatting condensation and moisture accumulation has been undertaken in Denmark. Field measurements of moisture content in a number of test roofs over long periods and under different conditions are evaluated and conclusions drawn. They include the advice that, where moisture accumulation is a problem, it can be aggravated if roof vents are installed.
The aerodynamic forces affecting wind and rain penetration of roofs are described. They are: 1 the wind and its turbulent nature, 2 the induced pressure field, 3 the air flows in contact with the roof and 4 the characteristics of the roof (internal pressure, permeability, structure, etc).
Recent work has demonstrated the existence of daily and seasonal cycles in attic moisture parameters. Over the course of a day, the attic air humidity may vary by a factor of three, and during the course of a winter there isstorage of perhaps
The theoretical background, admittance measurements and experimental work on interstitial condensation in lightweight roofs caused by air leakages is discussed. Describes a theoretical model of condensation behaviour taking into account moisture transfer by air flow as well as diffusion. Gives the air flow admittance for various roofing materials, ceiling systems and different roof-sections. Experimental results agreed well with the theoretical model.
Outlines the fundamentals of insulation and airtightness, proper air quality, and ventilation. Presents details of design and construction for walls, roofs, foundations, windows, and air-vapour barriers, as well as discussions of ventilation systems, heating systems, appliances and methods of testing and evaluation. One of the appendices gives weather data for selected US and Canadian cities. Aims to be accessible to the interested layperson or homeowner.
Dynamic insulation is a means of reducing building heat losses to near zero without the use of massive thermal insulation. It relies on recycling the heat conducted through the fabric or reducing the temperature gradient by means of a suitable heat transport fluid - usually air and sometimes water. Describes research and experience in Sweden and France. In Sweden, some 80,000 m2 of roofs (mostly of single storey sheeted structures) use the contraflow system of dynamic insulation and there have been a few experimental installations in the housing sector.
Discusses insulation of lofts, roofs, walls, windows and floors, natural ventilation of dwellings and mechanical ventilation with heat recovery in dwellings. Considers cost benefits of weatherstripping and constant-flow ventilators for naturally ventilated houses. Concludes that installation of mechanical ventilation with heat recovery is uneconomic, but adding a heatexchanger to an existing mechanical ventilation system has economic benefits.
With correct application of vapour barriers the ventilation of building structures is in general not necessary, unless such barriers prevent the escape of trapped moisture from moisture-sensitive - especially organic - materials. Indoor and outd