[0001] The invention relates to a method for repairing the exterior wall structures of a
building.
[0002] Constructing exterior wall structures made of stone material of buildings without
a ventilation gap, the so-called ventilation slot, has been the industry custom for
decades, at least in the Nordic countries. Exterior structures of stone material are
masonry, plastered and other exterior wall structures, which include stony material.
Because of the missing ventilation slot, such a structure is particularly sensitive
to damage due to moisture. Then, the wall itself and its insulating layer can be permanently
damp, which causes various health hazards. Microbes thriving in moisture, such as
e.g. mould fungi, weather the walls, spread in the building and cause symptoms of
diseases and a risk of losing health for people on the premises.
[0003] When repairing the stony exterior wall structures of such buildings, exterior wall
cladding is traditionally pulled down first, thermal insulations are removed and new
thermal insulations are installed. After this, the external cladding is re-built.
Then, it is important that plinths are widened such that a working ventilation slot
is provided in the structure. Such repair is sluggish and takes a long time. Furthermore,
the costs of repair are high and, even when repaired, the structures do not prevent
the weathering of the stony external claddings.
[0004] A method of repairing walls is known from
US 5 408 759. This known method includes the following steps: forming holes in the external cladding
at a distance from each other; through the holes, drying an insulation space behind
the external cladding and disinfecting with disinfectant; drying the insulation space
of the wall structure by installing a drying tube system in drying holes made in the
wall.
[0005] An object of the invention is to introduce a method for repairing exterior wall structures
coated with stone material having got wet and damaged by moisture without pulling
down the structures. A further object of the invention is to introduce a method with
which the thermal economy of the wall structure can be returned to the original level
and the exterior wall structure can also otherwise be made to operate in a way originally
intended. An additional object of the invention is to introduce a method using which
the health hazard caused by microbes in the structure for indoor air and people on
the premises is eliminated.
[0006] The object of the invention is achieved with a method, which is characterised by
what is presented in the claims.
[0007] In the method according to the invention, the transfer of moisture through the external
cladding to the wall structure is prevented by treating the external cladding with
façade protection, after which holes are formed in the external cladding and, through
the holes, an insulation space behind the external cladding is dried and disinfected
with disinfectant. Then, microbes in the insulation space are extinguished by disinfecting.
As the external cladding of the wall is treated with façade protection, its structure
cannot get wet any more, its normal operation is preserved and no new microbe growth
is formed in the structure. Therefore, the health hazard caused by the microbe growth
in the structure is eliminated and the health hazards due to the structures for people
on the premises are terminated.
[0008] Advantages provided with the method are also the significant savings in repair costs
and the considerable shortening of repair time, because there is no need to pull down
the wall structures. By the method, it is possible to provide a surface, which can
be kept clean more easily and cost-effectively than earlier.
[0009] Next, the different steps of the repair method will be described in more detail:
- 1. At the first step, the microbiological condition of thermal insulations in the
wall structure is examined by means of laboratory analyses. At the same time, the
dampness of the insulation space, the extent of wetness, microbe growths etc. are
measured. The drying of the wet façade structure is performed with side-channel or
equivalent blowers advantageously by means of preheated air.
- 2. The stony outer surface of the wall structure is cleaned with a method suitable
for the target and loose material is removed.
- 3. The outer surface is treated to prevent further wetness with a façade protection
agent suitable for the purpose, such as e.g. with an MCF façade protection agent.
The façade protection agent prevents the absorption of rainwater in the structure,
at the same time still allowing water vapour to transfer outside through the structure.
The surface protection does not change the appearance of the façade. The façade protection
agent is applied on the structure surfaces with a low-pressure sprayer or by rolling.
- 4. In the wall structure, drying holes are made at a distance from each other and
the insulation space is dried by installing a drying tube system in the drying holes.
The distance of the holes is such that air and disinfectant are able to spread everywhere.
That is, the distance is dependent on the structure, but it can be e.g. 1.2 metres
or less. In structures, which include a wooden frame, for instance, the distance of
studs is normally 600 mm and, when the holes must be in each gap of the studs, the
hole distance is 600 mm. The diameter of the holes and tubes is advantageously about
32 mm. The direction of drying air is determined by the way a structure, such as a
roof, is joined in the wall structure.
The drying can thus be performed depending on the situation from bottom to top, from
top to bottom or sideways.
- 5. As the drying is almost finished, smoke tracer is run along the drying air within
the structure. With the smoke tracer, it is possible to discover how tight the wall
structure is e.g. in window joints. At the same time, it is possible to see how well
the smoke travels in the insulation space. This information is important before disinfection.
With the smoke tracer test, it is also possible to find out if the rooms can be used
during disinfection.
- 6. After the drying has finished, disinfectant suitable for disinfecting insulations
damaged by microbes, such as MCF disinfectant, which is provided in aerosol form,
is conveyed as smoke-like via the drying tube into the wall structure. The way of
applying is determined based on the performed test and it considers, inter alia, construction
frames, the tightness of lining, the joining of the wall structure in the roof etc.
When required, the flow direction is reversed to ensure that the disinfectant penetrates
everywhere in the insulation space. If required, it is also possible to use the aid
of suction air. It is recommended that the disinfectant can be conveyed into the structure
such that the disinfectant goes pressurised within the structure, whereby it spreads
best in the insulation space.
- 7. The drying tube is removed from the structure. The holes of the tube systems in
the structure are repaired and the surface is treated with façade protection suitable
for the purpose, such as with MCF façade protection.
[0010] The method has been developed for several years. In the study, test walls were built
which were made to mould. Next, the studies were transferred to the exterior walls
of actual buildings. In the newest study, the insulation space was dried and, after
drying, the insulation space was disinfected according to the method. Before and after
the study, microbe samples were taken from the insulation space by means of which
it was possible to show microbiological changes possibly occurred in the structure.
[0011] The results of the samples showed that the badly moulded insulation space of the
exterior wall structure could be restored to the normal state. Repairing the mould
damage and drying the insulations restored the working condition of the thermal insulation.
Treating the external cladding with MCF façade protection prevents the structure from
damaging due to slanting rain.
[0012] Repairing the building façade with the new method was compared to a conventional
method in which the façade cladding is pulled down, the insulations are replaced and
the façade is re-built. The costs of the new method are about 15% of the costs of
the conventional method.
[0013] According to the design manual of the building regulations, the lifetime of a building
is assumed 50 years in design. When e.g. the exterior wall structure of a building
from the 1980s can be repaired with the more cost-effective repair such that no health
hazards occur nor the traditional damage mechanism is possible, an extremely great
economic advantage is gained. When more time, e.g. 20 years, is acquired with the
repair, the building is reaching the end of its lifetime. At this step, the building
in any case requires renovation at some extent. In the renovation to be performed,
there is necessarily no need to tamper with the exterior walls, unless e.g. extra
thermal insulation is required.
[0014] The method according to the invention advantageously employs MCF façade protection,
which protects façade faces and materials from moisture and salts as well as prevents
the growth of various moulds and microbes in the treated areas. The composition of
the product is the following:
- anionic and non-ionic tensides (TEA C6-20 sec. alkyl. sulphonate) less than 5%
- carefully selected polymer dispersants and cationactive guanidine copolymer (PHMG)
- UV-cleaned water
[0015] The pH of the prepared solution is normal and its specific weight about 1,000 g /
litre.
[0016] The polymer dispersant (moisture protection agent) used in this product is safe for
both materials and the environment as well as for the user. The treated surface retains
its natural porosity at the same time as it prevents water from penetrating the structure.
The surface is not yet steam-proof, but allows the structure to breath normally. The
cationic copolymer guanidine (PHMG) used to prevent the growth of mould and bacteria
acts in a physical way, not chemical, and it is thus almost impossible for microbes
and bacteria to develop resistance to it. PHMG forms on surfaces and in liquids polymer
chains, which puncture and destroy the cell walls of unicellular organisms coming
into contact with it.
[0017] MCF façade protection is a ready-prepared solution. The product is applied with a
brush, a roll or a sprayer into an even layer onto the surface being treated. The
intersection of plates and surfaces are also treated carefully. No special protection
equipment, except for a respirator mask, is required when applying the product. The
recommended use and storage temperature is normal working temperature. The product
dries in a few hours in normal moisture and temperature.
[0018] MCF façade protection does not contain scents or colourings. The tensides used in
the product are easily and quickly biodegradable according to EU regulations. The
product contains no alcohols, solvents or other components harmful to respiration
or organs. It does not gasify or emit harmful particles. The product does not absorb
in the skin or dry mucous membranes.
[0019] The invention and its implementation are not limited to the described materials,
but it can vary within the scope of the inventive idea presented in the claims.
1. A method for repairing exterior wall structures,
characterised by including the following steps:
- examining the microbiological condition of thermal insulations in the wall structure
by means of analyses and measuring the moisture in the insulation space,
- cleaning the stony outer surface of the wall structure with a method suitable for
the target and removing loose material,
- treating the outer surface of the wall structure to prevent further wetness with
a facade protection agent,
- forming holes in the external cladding at a distance from each other and,
- through the holes, drying an insulation space behind the external cladding and disinfecting
with disinfectant,
- drying the insulation space of the wall structure by installing a drying tube system
in drying holes made in the wall,
- conveying smoke tracer along with drying air,
- when the drying has finished, conveying disinfectant in smoke-like form via the
drying tube system to the wall structure, and
- removing the drying tube system from the structure, repairing the holes of the tube
systems in the structure and treating the surface with a façade protection.
2. A method for repairing exterior wall structures according to claim 1, characterised by, when conveying disinfectant to the wall structure, reversing the flow direction
to ensure the penetration of the disinfectant everywhere in the insulation space.
3. A method for repairing exterior wall structures according to claim 1 or 2, characterised by, when conveying disinfectant to the wall structure, using the aid of suction air.
1. Verfahren zum Reparieren von Außenwandstrukturen,
gekennzeichnet durch die Aufnahme der folgenden Schritte:
- Untersuchen des mikrobiologischen Zustandes der Wärmedämmungen in den Wandstrukturen
mittels Analysen und Messungen der Feuchtigkeit im Dämmraum,
- Reinigen der steinigen Außenfläche der Wandstruktur mit einem Verfahren, das sich
für das Ziel eignet, und Entfernen von losem Material,
- Behandeln der Außenfläche der Wandstruktur, um weitere Feuchtigkeit mit einem Fassadenschutzmittel
zu verhindern,
- Bilden von Löchern in der Außenverkleidung mit einem Abstand voneinander, und
- Trocknen eines Dämmraums hinter der Außenverkleidung durch die Löcher und Desinfizieren mit einem Desinfektionsmittel,
- Trocknen des Dämmraums der Wandstruktur durch Installieren eines Trocknungsrohrsystems in Trocknungslöchern, die in der Wand hergestellt
wurden,
- Übertragen von Rauchmarkierer zusammen mit Trocknungsluft,
- wenn das Trocknen beendet ist, Übertragen von Desinfektionsmittel in Rauchform über
das Trocknungsrohrsystem auf die Wandstruktur, und
- Entfernen des Trocknungsrohrsystems aus der Struktur, Reparieren der Löcher des
Rohrsystems in der Struktur und Behandeln der Oberfläche mit Fassadenschutz.
2. Verfahren zum Reparieren von Außenwandstrukturen nach Anspruch 1, dadurch gekennzeichnet, dass beim Übertragen von Desinfektionsmittel auf die Wandstruktur die Strömungsrichtung
umgekehrt wird, um das Eindringen des Desinfektionsmittels überall im Dämmraum sicherzustellen.
3. Verfahren zum Reparieren von Außenwandstrukturen nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass beim Übertragen von Desinfektionsmittel auf die Wandstruktur Saugluft verwendet wird.
1. Procédé pour la réparation de structures de mur extérieur,
caractérisé en ce qu'il comprend les étapes suivantes :
- examen de l'état microbiologique d'isolations thermiques dans la structure de mur
au moyen d'analyses et en mesurant l'humidité dans l'espace d'isolation,
- nettoyage de la surface extérieure en pierre de la structure de mur à l'aide d'une
méthode appropriée pour la cible et en ôtant les matières détachées,
- traitement de la surface extérieure de la structure de mur pour empêcher davantage
d'humidité avec un agent de protection de façade,
- formation de trous dans le revêtement extérieur à une distance les uns des autres,
- à travers les trous, séchage d'un espace d'isolation derrière le revêtement extérieur
et désinfection à l'aide d'un désinfectant,
- séchage de l'espace d'isolation de la structure de mur en installant un système
de tubes de séchage dans des trous de séchage formés dans le mur,
- transport d'un traceur de fumée ensemble avec de l'air de séchage,
- une fois le séchage terminé, transport de désinfectant sous forme de fumée par le
biais du système de tubes de séchage vers la structure de mur, et
- retrait du système de tubes de séchage de la structure, réparation des trous des
systèmes de tubes dans la structure et traitement de la surface avec une protection
de façade.
2. Procédé pour la réparation de structures de mur extérieur selon la revendication 1,
caractérisé en ce que la direction de flux est inversée lors du transport de désinfectant vers la structure
de mur, pour assurer la pénétration du désinfectant dans l'ensemble de l'espace d'isolation.
3. Procédé pour la réparation de structures de mur extérieur selon la revendication 1
ou 2, caractérisé en ce que de l'air d'aspiration est utilisé lors du transport de désinfectant vers la structure
de mur.