Abstract: This Digest reviews the effect of wind on people and discusses wind speed changes induced by buildings. Mechanical effects that make it difficult to walk and the thermal effects of wind are considered.
Abstract: This Digest defines vapour barriers used to control the movement of water vapour into walls and roofs. It outlines some of their limitations as well as clarifying the relative importance of water movement into walls by diffusion and air currents.
Abstract: Moisture traps in roof systems should be avoided. Where a double membrane system is to be provided this can be accomplished by designing a vented system. Breather vents can relieve vapour pressure and provide for drying of small quantities of moisture over a relatively long period of time. They tend to be unsuccessful in drying wet roofs unless wetting can be eliminated at the source and the venting system designed to facilitate drying. Venting can be achieved without stack vents [see CBD-99] or systems can be used that do not need vents [see CBD-150].
Abstract: Most silo foundation failures occur when it is loaded for the first time. Pressures rise in the pore water which reduces the frictional component between the particles and hence cause a reduction in the shear strength of the soil. If, at maximum load, the applied stresses are greater than the shear strength of the soil, the soil fails. It is normal for the tower to overturn with failure taking place along a circular arc. If the foundation does not fail during the first loading the structure will be stable for subsequent loadings. To determine bearing capacity of a soil shear strength, measurements are required to a depth below the footings equal to 2/3 the diameter of the foundation. Shear strength may be measured in the field by means of a field vane or cone, or in the laboratory by unconfined compression or triaxial strength tests on undisturbed samples of the soil. Adequate attention should be given to the reinforcement of the ring foundation, the quality of concrete, the centering of the silo on the footing and the interaction of silo groups which should not be closer than the diameter of the silo.
Abstract: This Digest summarizes the present state of knowledge concerning the fire hazard of plastic foam insulation material. It outlines some of the tests used to determine the flammability of plastics as well as surface burning characteristics and methods of evaluating the smoke and toxic gas hazard.
Abstract: This Digest outlines the general factors governing the waterproofing system in a roof. It then gives practical guidelines for a roof inspection and maintenance program to prevent roofing failures or permit repairs to be carried out at an early stage.
Abstract: This Digest provides general background information on ground temperature measurements available in Canada, the factors affecting ground temperature and the limitations to estimating or calculating these temperatures at a site.
Abstract: This Digest outlines the factors involved in membrane shrinkage and suggests methods for controlling them. It includes a list of practical guidelines for those preparing drawings and specifications and installing built-up roofs.
Abstract: In most parts of Canada the ground freezes during the winter months to depths varying from a few inches in mild areas to several feet in colder regions. Such ground freezing can lead to heaving of buildings located above or adjacent to it. The forces involved can be very destructive to lightly- loaded structures and cause serious problems in major ones. This Digest outlines the causes of frost action, some of the construction problems it presents, and the steps that may be taken to control it.
Abstract: This Digest outlines some of the principles that can be followed to control drainage and prevent erosion at construction sites. It is designed for the non-specialist, outlining the problem and presenting general guidelines. The Digest is a sequel to CBD 156, which is concerned with good drainage practice around buildings.