Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/70—Drying or keeping dry, e.g. by air vents
  • E04B1/7069—Drying or keeping dry, e.g. by air vents by ventilating
  • E04B1/7092—Temporary mechanical ventilation of damp layers, e.g. insulation of a floating floor

Definitions

• the invention relates to a method and apparatus for drying out a concrete floor structure with its associated filling and flooring that have been damaged by moisture or water. Drying takes place with the aid of air which is led into air-permeable layers in this structure.
• the object of the invention is to provide a method and apparatus which makes it possible, in most cases, and without even locally breaking up the floor, even to dry a concrete support structure which is completely soaked with water.
• Figure 1 schematically illustrates a vertical, partial section through a support structure with filling and flooring, apparatus in accordance with the invention being applied in and on the floor.
• Figure 2 schematically illustrates in plan the principle of localizing a plurality of narrow holes in the floor for the supply of drying air.
• FIG. 3 is a block diagram of the most important components included in an apparatus in accordance with the invention.
• Figure 4 illustrates to a larger scale an injection tube for air.
• the floor illustrated in Figure 1 is an example of a type of floor structure which has seldom allowed itself to be rehabilitated after moisture and water damage without breaking up the whole floor.
• the support structure 1 itself consists of a concrete slab resting on an insulating layer 2, e.g. of hot-cut and thereby substantially waterproof and diffusion-proof cellular plastics, which in turn rests on a draining layer 3 in the ground.
• Above the concrete slab 1 there is a screeded sand layer 4.
• a diffusion-tight film 6 may be arranged between the filling consisting of the sand layer 4 and the flooring 5.
• the spaces between the grains of sand of the filling as well as the space between the film 6 and flooring 5 form air-permeable layers in a horizontal direction. If there is water damage, a floor of this kind can take up considerable quantities of water.
• the concrete slab 1 can be completely soaked with water, and it may also be that there is water above, as well as below, the slab.
• a plurality of narrow holes 7 are drilled through the flooring 5 down to the filling 4. These holes are intended for use as supply orifices for drying air to the filling. Outlet openings for exhaust air from this air-permeable layer are arranged by removing the skirting boards, air gaps 8 generally being thus obtained along the walls 9 adjacent the floor in the room without further measures.
• an air injection tube 10 with sufficient length for projecting into, and almost through, the sand layer 4.
• the holes 7 are distributed over central portions of the floor surface and arranged in several parallel rows. They are suitably arranged with a spacing of 10 - 50 cms in each row, preferably about 15 cm. The diameter of the holes do not need to exceed 2 mms , since the tubes 10 are suitably made from piping with this diameter as a maximum.
• Figure 4 illustrates more closely how such a tube has its upper open end inserted in the wall of a hose 11.
• the wall of the tube is in turn provided with some axially spaced holes 12 serving as outlet orifices for drying air at different levels in the filling 4.
• the length of the tubes 10 and the number of holes 12 is adjusted to the object being worked on.
• the bottom ends of the tubes do not need to be open.
• a hose 11 is disposed along each row of holes 7 in the floor.
• Such a hose is illustrated in Figure 1 , but the hoses have been excluded from Figure 2.
• the principle sketch As is illustrated in the principle sketch,
• the hoses are adapted for being connected to a pressurized air source 13 delivering compressed air, which has been dehumidified, and also treated with respect to its temperature.
• a heater in the form of one or more mattresslike heating pads, is placed on the floor ( Figure 1), the pads being upwardly covered with a heat-insulating and preferably reflecting material 15, which may either be integral with the pads or made as separate matting.
• the heating pads are heated by unillustrated internal hot water coils or electric coils.
• the drying process proper is started after these preparatory measures by the compressed air flow, which has a low absolute humidity of preferably about 0.2 gram water/m 3 air and substantial excess temperature in relation to the initial temperature of the floor structure, being supplied from the source 13 to the sand filling 4 via the hoses 11 and injection tubes 10.
• a suitable temperature is normally 30 to 50oC.
• the floor surface is simultaneously heated by the heater 14 to the same temperature as the compressed air, or to a higher temperature, preferably about 10oC higher.
• a revealant measuring point 16 can often be obtained by removing a threshold ( Figure 2) and finding a point in contact with the air-permeable layer, i.e. the sand filling 4.
• the pre-determined first value is suitably a relative humidity of 60 - 65 %. It may also be suitable to drill a hole under the threshold down into, or through, the concrete slab 1 for measuring the temperature under it, or in it, near the underside of the slab in the latter case.
• the measuring point can be of value partly for determining the original temperature level of the floor structure and the temperature gradient, and also for monitoring temperature changes at the underside of the concrete slab. It is suitable here not only to ensure that the mentioned first value for the moisture in the air which has passed the filling is achieved, but also that the temperature at the deeper level rises to 25 - 30°C before the application of heat via the compressed air stream and floor surface is broken off.
• the heating and drying procedure can require a time of some days before the desired values are obtained.
• the temperature of the compressed air stream which is still supplied dehumidified, is subsequently lowered to accelerate the moisture migration from below to the dried-out area, i.e. the sand filling 4, flooring 5 and the upper portion of the concrete slab 1.
• the floor surface heating is simultaneously broken off or reduced.
• the compressed air supply temperature is preferably reduced to the order of magnitude +10oC.
• the dried and colder compressed air stream is maintained until the moisture under the concrete slab 1 or in the concrete close to the underside of the slab has dropped to a predetermined second value, indicating that desired drying of the area in or below the concrete has also been achieved. Measurements in this area are suitably made through the previously-mentioned hole under the threshold.
• the compressed air supply can be broken off when the temperature has dropped to 15 - 17oC and the relative humidity of the air has dropped to about 70 % in this area. This cooling process can also take some days to carry out. Should it be found that the relative humidity does not sink to the desired level, after a fairly long compressed air supply time, selected by experience, the whole of the described heating and cooling cycle is repeated until this desired final state is arrived at.
• the compressed air stream is supplied through all the holes 7 made in the flooring in Figure 2 , there being thus obtained for the entire floor area a flow picture of the kind indicated to the left of the chain-dotted line in the Figure, i.e. from the centre and out towards the edges for departure via all the gaps 8.
• all the gaps 8 except one can be taped over.
• the room where the floor is being dried is suitably provided with temporary apparatus, known per se , for improving ventilation, so that damp air and excess heat is led from it.
• the compressed air source 13 supplying dehumidified compressed air to the tubes 10 via the hoses 11, this air being also treated with respect to its temperature, comprises an air compressor 20 with a cooler 21 , a dehumidifying apparatus 22 with two alternatively connnectable or regenerable dehumidifying units, a cooling battery 23 (in circuit with a cooling compressor 24) and a heating battery 25, e.g. heated with excess heat from the cooler 21 of the air compressor 20.
• the mattress-like heating pad 14 for heating the floor surface may, at least to some extent, be heated with water from the cooler 21 of the air compressor or the condenser of the cooling compressor 24.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Drying Of Solid Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=20348490

Family Applications (1)

Country Status (6)

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• 1982
  • 1982-11-08 SE SE8206321A patent/SE435946B/sv not_active IP Right Cessation
• 1983
  • 1983-11-07 EP EP83903609A patent/EP0141815A1/en not_active Withdrawn
  • 1983-11-07 WO PCT/SE1983/000380 patent/WO1984001794A1/en active IP Right Grant
• 1984
  • 1984-06-28 DK DK315084A patent/DK315084A/da not_active Application Discontinuation
  • 1984-06-29 NO NO84842655A patent/NO154731C/no unknown
  • 1984-12-07 FI FI844837A patent/FI75205C/fi not_active IP Right Cessation

Non-Patent Citations (1)

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