foundation

Rising moisture from the ground has caused quite a lot of damage on foundations of Swedish buildings, in particular for the type concrete slab on the ground. Some of these constructions may be repaired by mechanical ventilation, for example below the floor or below the concrete slab , if there is an air-permeable layer below the slab. Summarized results from a few field studies and tests, which have been going on for a period of 2-3 years, are reported. Different methods with mechanical ventilation systems have been found to work quite well so far, i.e.

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.

Tests a method which determines the infiltration of air and radon from the soil to a building. Makes measurements of total air flow along with usual airtightness tests. Describes practical tests in a detached house with a raft foundation on a gravel esker, and determines the permeability curves for thewhole house and the raft alone, and also the permeability of the soil to air. Describes the way the results are used for determination of air infiltration in different climatic conditions, and tests different radon reducing methodsusing the previously developed system analysis.

The radon contents in the two wings of a university building in Tampere were measured. Outside air was supplied to the corridors where it flowed to the rooms via ceiling ducts. Lower radon values were obtained in the rooms located close to the air supply end of the corridor. Radon content was also higher on the first floor then on higher floors, probably because of radon emission from the gravel layer in the foundation. Notes that the main source of radon in a wooden building is the ground, and the tightness of the floor construction is therefore very important.

Discusses relatively simple and inexpensive method for ventilating house foundations to reduce radon based on results of a trial on detached housing in Sweden. Principle is to extract radon gas from the ground before it enters living accomodation. Table shows radon daughter intensity before and after corrective measures.