The present invention concerns a

proceeding attending to facades on buildings which have been damaged or which risk being damaged by penetration of moisture in the walls of exterior insulation and finishing system on timber frame. Background of the risk construction EIFS-TF

It is known that the water that has penetrated behind Exterior Insulation and Finishing System (EIFS, SE: " Enstegstatad Putsad Fasad") on Timber Frame, hereinafter EIFS-TF, consisting of render on thermal insulation of, for instance, mineral wool, cellular plastic, or other material, dries out slowly and that organic material of the framework of the building as well as other organic materials of the external wall, such as gypsum boards, scantlings, insulation, etc., may become attacked by mould and rot, which may shorten the technical service life of the external wall. This constitutes a sanitary problem since odours and other emission from damaged materials may penetrate into the occupied zone of the building or in another way contact and affect people's health negatively, so-called Sick Building Syndrome (SBS) , or in another way may have undesired impact on the

building or its population.

Estimates by SP Technical Research

Institute of Sweden maintain that in Sweden, at least 25 000 houses have been built with EIFS-TF and that 40-

50 % of these houses have moisture damage to a greater or lesser degree and are now in need of repair. Prevailing principles of renovation of EIFS-TF

At present, these damaged facades are attended to according to two main principles, viz.

A) by "Partial repairs", and

B) "Replacement of facade"

Partial repairs of damaged EIFS-TF are carried out by replacing damaged material and parts thereof by moisture proof healthy material and using approved methods .

At present, undamaged portions are

normally left unaddressed but it is risked thereby that also such portions, which now are undamaged and have not been exposed to moisture and mould, will be damaged in the future .

When there are large damaged portions, the normal method is to demolish EIFS-TF all the way into the supporting framework of the house. Possible damage to the framework is taken care of and then a new facade is fitted. Often, a two-sealant system is then selected and thereby a moisture proof facade is obtained. House owners with undamaged EIFS-TF, still replace their facade at present, in spite of it not being damaged, since they not want to have a facade with a large risk of being damaged by moisture at a later stage. Houses with EIFS-TF are at present not coveted on the market, since they are

difficult to sell and have a lower value than the

corresponding healthy house without EIFS-TF.

Therefore, the main object of the present invention is primarily to provide a proceeding of the type mentioned that prevents or at least decreases the risk of water penetrating into houses with EIFS-TF.

Said object is achieved by means of a proceeding according to the present invention, which essentially is characterized in that (I), after it is checked if possible penetration of moisture has occurred in the building wall in question and when such has been demonstrated, restoration of the building wall into functional use has been accomplished, (II) there is fitted a pervious and air pressure-equalizing, intermediate layer, along the outside of the facade of existing, at least essentially air-proof and hydrophobic building wall and the principal function of which is to equalize the air pressure on both sides of a rain seal situated outermost, and (III) which said rain seal forms an outer layer of said building wall.

The invention generally indicated

The invention is a construction

proceeding, which aims at supplementing and on-site upgrading EIFS-TF in a reliable and controlled way. The moisture-proofness of the facades is thereby considerably improved from being EIFS-TF, i.e., ONE-sealant

(significant risk of moisture) to become TWO- sealant (established moisture proof) .

The technical level is that the

construction system guarantees a new and requested function ( two- sealant , moisture-proofness) of the facade without craftsmen having to demolish and deposit the existing materials and then mount a new facade system.

By utilizing, methodically and in the correct order, a combination of different methods I, II, and III, which individually are known from other

applications, the moisture-proofness of the risk

construction EIFS-TF is guaranteed in three steps/layers, each one of which separately and together has the same high moisture-proofness as an entirely new facade system of the latest art.

Thus, the invention concerns an on-site mounted construction proceeding for supplementing,

upgrading, and guaranteeing the moisture-proofness of so- called Exterior Insulation and Finishing I Systems on Timber Frames (EIFS-TF) .

The construction proceeding concerns fitting integratedly on the outside of the existing EIFS facade. The existing facade still preserves several structural properties such as carrying load, thermally insulating, and sound-insulating, etc.

Layer I - Air-proof and hydrophobic function

The first layer I included in the

invention has the function to be air-proof and

hydrophobic. The construction system is based on using the existing facade as a starting point for this layer. The front face is prepared so that it meets the requirements of being air-proof, for instance by larger defects being mended with plaster, cracks and fittings being covered by a sealing material, such as a frame protection applicable by rolling or a flexible tape, or something else. The surface of the facade, which is facing outward from the building wall in question, is also prepared so that its properties meet the requirements of being hydrophobic, by, for instance, treating sucking surfaces with an

impregnating agent or coating them with a frame protection applicable by rolling, or something else. Damaged or weak portions are reinforced or replaced by, for instance, new materials, plaster-mending, or using another method that provides desired properties of the prepared surface. Layer II - Pervious and air pressure-equalizing layer.

The intermediate layer II has as principal function to equalize the air pressure on both sides of the outermost rain seal so that there do not arise permanent differences of the air pressure, which may risk bringing in water into the structure or have other consequences. This intermediate layer may also be arranged so that it has the ability to be able to convey out possibly

penetrating water from the structure. The intermediate layer II may, for instance, consist of a pervious air gap, which has been arranged inside a plaster-carrying external board or some other suitable material. For instance, the gap may be arranged by the board having been fitted on laths or spacers, which are attached to the existing facade, or that the back side of the board in itself is formed as spacers or in some other suitable way.

The intermediate layer II may consist of a material that, for instance, is sufficiently permeable to air for allowing an air pressure-equalizing function. It may, for instance, be a question of permeable mineral wool, pervious insulating boards, or other materials having an inner or outer structure that allows the

indicated desired properties and function. Layer III - Rain seal

The outermost layer III of the

construction system has as a function to protect the structure against rain. The same layer III consists of a material or a combination of materials which have the purpose of being a decorative and functional front face. A rain- sealing material combination may, for instance, consist of a combination of materials that have curing, reinforcing, hydrophobic, or other properties. For instance, a reinforced plaster system, which has been applied to a plaster-carrying board material and is fitted outside an air gap or a material, may be provided with a hydrophobic finishing coat, thin brick, glass mosaic, or something else.

The plaster system, the plaster-carrying board, or some other facade material may be fitted

directly on said material II that constitutes the

intermediate layer II of the construction system, or on laths or pressure spacers, or in another way.

List of Figures

The invention is described below in the form of a number of preferred embodiment examples, reference being made to the accompanying drawings, in which

Fig. 1 shows a schematic section view of a building wall with the three proceeding steps comprised by the invention,

Fig. 2 shows a first step,

Fig. 3 shows a second step ready for the application of a rain seal according to step III, and

Fig. 4 shows a said third step.

According to the invention, there is carried out a proceeding attending to facades 1 on buildings which have been damaged or which risk being damaged by penetration of moisture in the walls 2 of exterior insulation and finishing system 1 on timber frame 3 according to the following steps I-III:

After it is checked if possible

penetration of moisture has occurred in the building wall 2 in question and when said such a penetration of moisture has been demonstrated, e.g., after insertion checking by moisture instrument, and restoration of the building wall 2 into functional use according to step I has been

accomplished, it is proceeded from step I to step II.

(Fig. 1)

In step II, a pervious and air pressure- equalizing, intermediate layer 4 is fitted along the outside of the fa ade 1 of existing, at least essentially air-proof and hydrophobic building wall. The principal function thereof is to equalize the air pressure on both sides of a rain seal 5 situated outermost, which is arranged in a step III. This said rain seal 5 forms an outer layer of said building wall 2. (Figs. 3 and 4)

Partial repairs in step (I) of the facade 1 are accomplished so that the same meets the requirements of being air-proof, for instance by larger defects being mended with plaster, cracks and fittings being sealed, for instance by a frame protection applicable by rolling or by a flexible tape.

The surface 1A of the facade 1 in step (I) is prepared so that its properties meet the requirements of being hydrophobic, for instance by treating sucking surfaces with an impregnating agent or by coating them with a frame protection 10 applicable by rolling 11. (Fig. 2)

Damaged or weak portions in step (I) are reinforced or replaced by, for instance, new materials, mended with plaster, or that another suitable method is utilized so that desired properties of the prepared surface in step (I) are accomplished.

In step (II) , the pervious and air

pressure-equalizing intermediate layer 12 is fitted and thereby the risk is prevented or at least decreased of bringing in water into the structure of the building wall 2. (Fig. 3)

Suitably, an intermediate layer is fitted, which also has the ability of being able to convey out possibly penetrating water from the structure of said building wall and said intermediate layer may consist of a pervious air gap, which is arranged inside a plaster- carrying external board on laths or spacers against the existing facade 1. (Fig. 3)

In that connection, there may, on the back side of a plaster-carrying external board, be arranged spacers in factory.

Layers consisting of material permeable to air are fitted to provide an air pressure-equalizing function, for instance permeable mineral wool, pervious thermal insulating board, or other material having

internal structure that affords desired air pressure- equalizing function of said external step (III) for the formation of a rain seal layer 15. (Fig. 4)

For external, rain-sealing layer 15, it is selected a material having a decorative and functional front face, for instance a hydrophobic finishing coat, thin brick, or glass mosaic, or a reinforced plaster system, which is applied to a plaster-carrying board material for fitting outside an air gap. In that

connection, the rain-sealing layer 15 in the form of, e.g., a plaster system, plaster-carrying board, etc., is fitted directly on the pervious intermediate layer of the building wall, on laths, or on pressure spacers. (Fig. 4).

Function and nature of the invention should have been clearly understood from the above- mentioned and also with knowledge of what is shown in the drawings but the invention is naturally not limited to the embodiments described above and shown in the accompanying drawings. Modifications are feasible, particularly as for the nature of the different parts, or by using an

equivalent technique, without departing from the

protection area of the invention, such as it is defined in the claims.