At high groundwater level, in order to avoid complex waterproofing works, exploited underground rooms are often made not deep, in the form of crawl spaces with the inside height of 100-150 cm.
The crawl space foundation repair is performed with bitumen or brick, lower for 20-30 cm from the crawl space flooring level. In order to avoid the decay of sole plate and overlap wooden parts the crawl space should be ventilated. For this purpose make 15×15-sized bores in the sole plate part of the wall, at the height of 20 cm minimum. In winter they are usually bricked in.
Such crawl spaces, as basements, are covered with sole plate or bracing from the outside and they have heat-insulated socular covering, however, unlike basements, they have less permanent temperature condition. The flooring of not deep crawl space, in comparison with the basement, is more likely exposed to temperature spans.
If a heat-insulated crawl space is provided in the house and the ground under it freezes through, such crawl space is considered to be a cold one. Usually it is also closed with sole plate or bracing from the outside and therefore it is protected from wind, rain and snow, however its temperature condition is mostly defined by the temperature of outdoor air.
At socular wooden covering, in order to prevent the wood from biodeterioration, it is better to provide good cross ventilation when performing the crawl space foundation repair. It will be useful to cover wet ground with rubberoid, placing spall above it in order to reduce the direct impact of soil moisture to wooden constructions, especially during the ground defrosting,
In country houses with permanent operational temperature condition, floors are often made on rails, laid on brick columns, that lean directly to the ground. Under floor planks a warm crawl space is formed of 150-250 mm height. At bigger height heat looses increase, at less one – its ventilation worsens. From the inside, along the perimeter of outside walls, the sole plate is insulated with molten ash, expanded clay, silicate wool. It is important to take into account that such ground flooring construction is contraindicative for cottage houses and garden cottages with inconstant exploitation regime. Sometimes they construct cellar under the floor, designed for storage of small stock of products.
Cellar walls, unlike basement or crawl space ones, are not necessary to be connected with the foundation and are usually made of brick and concrete. The best cellar shape is considered to be rounded one. It allows to construct comparatively thin walls, to comfortably dispose areas of product storing, to avoid hard-to-exploit corners.