WO1987000224A1

WO1987000224A1 - A method and means for providing a moisture barrier

Info

Publication number: WO1987000224A1
Application number: PCT/SE1986/000322
Authority: WO
Inventors: Rolf CEDERSTRÖM
Original assignee: Cederstrom Rolf
Priority date: 1985-07-02
Filing date: 1986-07-02
Publication date: 1987-01-15
Also published as: SE8503297D0; EP0227791A1; SE461408B; SE8503297L; AU6143086A

Abstract

A method for the provision of moisture migration barring layer within brick work walls and structures, comprising drilling holes (11) in the structure and drying the same to permit introduction of a hydrophobing agent. The drying is carried out by blowing into at least certain of the holes of a drying medium having a low relative humidity, preferably hot compressed air and under optimal control of at least two essential parameters for the drying result, viz. the difference of relative humidity between the drying medium and the superficial layer immediately adjacent the hole walls, the velocity of the drying medium and the evaporation. The hydrophobing agent is admitted in atomized or gaseous state during the drying step. An equipment for the provision of a moisture migration barring layer in building structures or the like by drilling holes (11) in the structure and providing a dried zone, that is hydrophobied, comprises means (12, 17) for the provision of drying air, preferably compressed air having a low relative humidity, and means for the provision of a hydrophobing agent in atomized or gaseous state.

Description

A method and means for providing a moisture barrier

The present invention relates to a method and an equip¬ ment for providing a moisture barrier in buildings.

Destroyment of buildings and building structures due to moisture has been documented to be of a considerable magni¬ tude, also globally. The term destroyment is used in this context to denote also such damages which make buildings of various kinds unuseful, entirely or at least partly, for- their itended purpose, such as mould damages in dwelling houses. The damages would appear to be primarily due to a capillary moisture migration in brick work walls. The need to find a way to stop further destroyment is well known.

In order to remedy the moisture migration problem it has been proposed already previously to provide a moisture barrier in the building structures by introducing a hydro- fobing agent into suitable zones. To permit the hydrofo- bing agent to function the building structure has to be dried in the relevant zones, i.e. the water in the capil¬ laries has to be removed within the zones that is intended to operate as a moisture barrier.

To perform the drying by admitting heat to the sides of the building structure so as to heat a zone thereof is uneconomical and cumbersome in practise. Therefore, it has been tested to use electroosmos and microwaves of the drying. In principle, this method has been carried out in such a manner that first a plurality of holes has been drilled in the wall whereupon electrodes, antennas or the like have been introduced into these holes, which are con¬ nected to a power source and are intended •to operate in such a manner that moisture/water is driven out from the capillaries within a zone of the wall. Finally, a suitable hydrofobing agent has been introduced through the holes in the wall. However, both the just mentioned drying methods are looked upon with a certain scepticism, both with res¬ pect to the efficiency and the security in handling.

The present invention has aimed at the provision of a method for providing moisture barriers whereby the draw¬ backs and deficiencies of the methods as hietherto used are remedied. To the just mentioned end it is proposed according to the present invention that the method should be carried into effect in such a manner as is defined in principle in the characterizing clause of claim 1.

The invention has also aimed at providing an equipment to be used in carrying the method into effect.

To the just mentioned end it is proposed that the equip¬ ment should be designed in such a manner as is defined in principle in the characterizing clause of claim 6.

The invention will now be described in more details with reference to the accompanying drawing.

Fig. 1 illustrates a portion of a brick work wall in horizontal section;

Fig. 2 illustrates a portion of a brick work wall, similarly in a horizontal section but to an enlarged scale_?

Fig. 3 is a side view of a brick work wall portion;

Fig. 4 i similar to fig. 3 but illustrates an alterna¬ tive conduit arrangement;

Figs. 5, 6, 7, 8, and 9 illustrate variations of the invention.

The basic principle according to the invention could be said, generally, to comprise drying the wall structure by using hot compressed air and carrying out the hydrofobing step by introducing hydrofobing agent in steam or mist shape when a certain amount of the moisture has been remo¬ ved, said hydrofobing step being carried out-simultaneously with a continued drying.

Fig. 1 illustrates a brick work wall portion 10 wherein a plurality of holes 11 has been drilled within a horizon¬ tal zone. The holes 11 may be oblique, as is shown in the drawing, but they may also run into the brick work perpen¬ dicularly to the surface thereof.

The holes may be disposed in one essentially horizontal row or may they be disposed in several rows, and the hori¬ zontal spacing between the holes may vary in dependence of the local requirements in each case. Normally, the holes 11 should not extend the full way through the wall struc¬ ture, as is shown, but in certain cases it would be possib¬ le within the scope of the invention to make the holes 11

throuhggoing, in which case they could either be provided with a sealing plug in one end or could they be used throughgoing as they are.

Fig. 2 illsutrates a brick wall portion 10 having a holw 11 wherein has been introduced a nozzle 12 for blowin in a drying medium from a conduit 13, if desired under control by a suitable valve 14. The mouth of the hole 11 is covered by a cap 15 through which the nozzle 12 extends and which is provided with a relief valve 16 of a suitable design to let out the drying air that has been blown into the hole.

In the arrangement as shown in fig. 3 the holes 11 for the admission of drying air are contemplated to be dispose in a lowermost, horizontal row, whereas holes 11A' for ad¬ mission of a heating medium are contemplated to be dispose in an uppermost horizontal row. If the holes are .disposed in one single horizontal row the holes may be contemplated to be disposed alternating with each other. . A similar alternating disposition is shown in fig. 4.

In fig. 3 it is shown schematically that the drying medium is admitted from a drying medium generator 17, whic may consist of an air compressor having a de-humidifier, whereas the heating medium is admitted from a heating medium generator 18. This one may, so to say, partially b constituted by the air compressor, wiz. in that it may consist of a heat exchanger, which utilizes heat from the compressor and/or the drive motor thereof.

The drying of the zone in question of the brick wall i contemplated to be carried out in principle in such a man¬ ner that drying medium is admitted through the nozzles 12 for drying in acordance with the so called HYAB-technique. This method comprises admission of compressed air of a ver low humidity in order to drive off moisture from the hole walls, partially in a mechanical manner in case the mois¬ ture is in a fluid state, and partially by a strong evapo¬ ration due to the air movement along the hole walls and du to the partial pressure differences. Because of the stron evaporation there takes place a moisture migration within the brick work, from innermost portions and outwardly to- wards the hole walls, which moisture migration is capillary sustained in that the capillary forces are disturbed by the air flow. To the last mentioned end it has been contemp¬ lated to make, in one way or another, the air flows pul¬ sating or alternating.

The moisture migration in the just described way from the innermost portions of the brick work towards the hole walls may be sustained further by introducing through cer¬ tain of the holes, such as the holes 11A, of hot eair which effects a heating of the surrounding wall material, in which case the moisture migration towards the colder por¬ tions around the holes 11 is sustained.

After the drying in the above described manner the hydrofobing agent is introduced through at least some of the holes 11, 11A, such as in the form a silanes, siloxanes or the like. In such a manner there is formed an efficient moisture barrier that prevents continued moisture migratioa through the brick work walls of the building structure.

Although it has not been clearly established as yet it should be mentioned that the above disclosed method of providing a horizontal moisture migration barrier probably could be modified somewhat in such a manner that it would also be possible to provide an effective, vertically run¬ ning moisture barrier, in which case it would be possible to prevent moisture penetration in brick work walls and the like from their normally vertical, outermost surfaces that are exposed to moisture penetration hazards.

It should also be mentioned that it would appear to be possible, complementary to the provision of a moisture barrier, to effect a reinforcing of weak brick work walls, for instance by means of silicone acid esters.

With reference to figs. 5, 6, 7, 8, and 9, the inven¬ tion may also be described in the following way:

Every second hole is used as an "inhole" 11A, and the alternating holes are used as "outholes" 11B. Into the holes 11A there is introduced, from a compressor A, hot compressed air which has been heated within a thermostate controlled heating source B. The hot air is introduced into hole 11A when the mouth has been provided with a sealing gasket 13 through which a conduit is passed, fig. 5.

In fig. 6 there is shown hos the outholes 11B are arranged. They are, via a switch C, couple to either a suction conduit 16 or a pressure conduit 15. The conduit 16 is provided with a separator D. The conduit_^15 is coup¬ led to the compressor without passing through the heating source B.

Fig. 7 illustrates the coupling of a receptacle E for the hydrofobing fluid. The receptacle may be pressurized through the conduits 14 and 15 when the valves F have been opened. Thereby, the pressure within the receptacle E will be the same as within the conduit 12.

At the same time as the hot air is blown into the wall via the holes 11A the outholes 11B are vented by means of non-heated compressed air via the conduit 15. The mouthes of the holes are thereby open. Alternatively, if desired, the suction out may take place through the holes 11A, in which case the conduit 16 is connected to a vacuumpump or the like, at the same time as the holes 11B are provided with sealing gaskets in the mouth thereof. In certain cases a switching between these both systems may be carried out.

^' When the moisture content of the brick work wall has been brought down to a suitable level the receptacle E is switched in, whereupon hydrofobing agent through the con¬ duit 15 is dripped into the pressure conduit 12, where it is atomized or gasified and is introduced into the brick work wall in the shape of minute drips or a gaseous state. At the same time, the suction conduit 16 is switched in via the switch C, and the outholes 11B a sealed off according to fig. 9. The introduction of hydrofobing liquid is con¬ tinued until a suitable quatity has been introduced. In the separator D any excess of the hydrofobing liquid may be reclaimed.

It should be observed that the invention would appear to be very well applicable for the provision of moisture barriers also on plate shaped house bases etc. , that are rest directly on the ground or close thereto. A plurality of modifications may be carried out within the scope of the invention, both with regard to the method and with regard to the equipment utilized.

Claims

1. A method for the provision of moisture migrating baring layers in brick work walls and the like in building structures, whereby hole (11) are drilled into the brick work wall and the wall is dried to permit introduction of a hydrofobing agent, characterized in that the drying is performed essentially by blowing into at least some of the holes of a drying medium having a low relative humidity,^" preferably heated compressed air, and under optimal control of at least two of the following parameters that are essen¬ tial to the drying effect, viz. the difference of relative humidity between the drying medium and the superficial layer immediately adjacent the hole walls, the velocity of the drying medium and the evaporation, and in that the hydrofobing agent is admitted in atomized or gaseous state during the drying step.

2. A method as claimed in claim 1, characterized in that a heating medium is blown in through certain others of the holes.

3. A method as claimed in claim 1 or 2, characterized in that the drying medium and/or the heating medium is blown in pulsating or alternating.

4. A method as claimed in one of claims 1-3, charac¬ terized in that a reinforcing agent, such as a silicon acid ester, is introduced in connection with the introduction of the hydrofobing agent or simultaneously therewith.

5. A method as claimed in one of claims 1-4, charac¬ terized in that there, during the introduction of the hydro¬ fobing agent or the reinforcing agent into the brick work wall, is upheld an environment that supports the introduc¬ tion of the said agent or has an influence on the proper¬ ties thereof, such as an elevated temperature.

6. An equipment for-the provision of a moisture bar¬ ring layer within brick work walls or the like in the man¬ ner as defined in one of claims 1-5, characterized by means for the admission of drying air and means for an optimal control of the parameters of the drying air.

7. An equipment as claimed in claim 6, characterized by means for admission of a heating medium to at least some of the holes.

8. An equipment as claimed -in claim 6 or 7, character¬ ized by means for shifting and/or pulsing of the drying medium and/or heating medium flows.

9. An equipment as claimed in one of claims 6-8, characterized in that the means for the provision of the^" heating medium is coupled together with at least a portion of the means for the provision of drying medium in order to utilize excess heat from the last mentioned one.