roof

Reports on experiments carried out on models with trough roofs in order to study the influence of parapet height and wind turbulence. The models were exposed to both turbulent shear flow and a smooth uniform flow. Pressure coefficients were c

Uses a multi-channel infra-red gas analyser to measure nitrous oxide tracer gas concentration at six points round a house. Combines concentrations to give overall house ventilation rates and to estimate the air exchange between individual rooms. The gas analyser is also used to measure air movement between the house and its roof (with 5 sampling points in the house and one in the roof). Results show that typically 20-30% of the air that enters a houseleaves via the roof space through gaps in the ceiling.

An experimental investigation of wind-induced pressure loads acting on two square-plan flat-roofed model structures (50ft and 225ft high in full scale) is described. Measurements of mean, peak and root mean square pressures acting on points and over larger roof areas have been made in turbulent boundary layer flow simulating wind over urban and open country terrains. Area loads on the roofs have been measured both by a pneumatic-averaging technique, and by using a large flush-diaphragm transducer.

Elucidates many different aspects of formaldehyde occurrence, such as, comparable indoor air pollutants, complaints and investigations, coherence with ventilation rate and construction, chipboard types, qualities and prices, differing European directives on board composition, chipboard in cold and warm types of flat roofs.

Reports study of wind and rain over fifteen years and gives table of results. Reports measurements of wind pressure and driving rain on buildings. Discusses laboratory measurements of the tightness of facade elements under pressures of up to 50 Pa. and with temperature differences of -40 to +30 deg.C. across the facade. Describes pressurization of buildings and gives results of measurements in test dwellings. Discusses movement of joints in buildings and describes measurement of this movement.< Discusses permeability of both flat and sloping roofs.

Steeply sloping ventilated roofs are preferred for single and two-family houses in West Germany. Notes lack of any scientifically substantiated notions concerning physical laws governing air exchange between ventilated zones and outside air. Describes air flow and heat transfer investigations in a 48 deg. sloping roof. Gives details of roof constructions. Illustrates roof space and distribution of thermocouples and arrangement for injecting tracer gas. Describes experimental procedure. Provides some measurement results. Compares theoretical bases with experimental results.

In projects to rehabilitate old buildings in Canada, it is general practice to clear out the entire interior of a building, leaving only the structure and some or all of the exterior walls and roof. The new interior conditions impose more severe loads on the building envelope and hence walls and roofs must be upgraded. Discusses improvement of walls and roofs to increase airtightness, reduce rain penetration and conserve energy use. Discusses the effect of insulation and the location of insulation on the envelope performance and possible types of wall and roof modification.

Air leakage through the junction between wall and roof of a building can cause damage from excess dampness. Discusses in detail the problem of constructing atight wall/roof junction for different forms of roof construction. describes installation of roof membrane and vapour barrier.< Also describes problem of air infiltration through uninsulated soffits. Outlines various solutions.

Increasing use is made of open front or cold confinement buildings for fattening beef cattle. Reports model study of an open front beef confinement building a) to evaluate the effects of ridge vent design on airflow characteristics and temperature and b) to determine prediction equations forthe relationship between wind velocity and outlet velocity. Reviews literature on the subject. Compares results with previous studies. Discusses relationships between outlet velocity, wind speed and temperature difference. Recommends open and baffled ridge vents.

Sets out in general terms the design principles for avoiding condensation in roofs, pitched and flat. Recommends providing arain shield permeable to water vapour, a vapour barrier on thewarm side of the structure and in roofs with air spaces to ventilate the air space or blow dry air into the roof space.Discusses application of these to particular types of roofs.