DE102008039857A1 - Thermally insulated metallic roof and gutter constructions moisture detecting method, involves changing impedance value during entry of humidity into roof construction, and detecting and evaluating change of impedance - Google Patents

Abstract

The method involves forming an electrode of a plate condenser by a roof outer skin (7) of a thermally insulated metallic roof construction (1), where the plate condenser has a reference impedance value in a dry condition. Another electrode of the plate condenser is formed by a carrying tray (3) of the construction. The tray is connected with a building construction. An impedance value is changed compared to the reference value during entry of humidity into the roof construction, and the change of impedance is detected and evaluated. The skin is designed on a crush insulator (5). An independent claim is also included for an arrangement for detecting moisture in a thermal insulated metallic roof construction.

Description

The The invention relates to a method for detecting moisture in heat-insulated metallic roof and gutter constructions, which have a clam shell Construction with interim heat insulation and Have vapor barrier. The invention also relates an arrangement for carrying out the method.

[State of the art]

For locating leaks on flat roofs is according to DE 199 21 556 C2 a corresponding method known.

These Arrangement comprises a device which is suitable to a apply a test signal to the first measuring circuit, by closing this measuring circuit by means of a Abtastleiters a from the distance of the Abtastleiters to the place of Leakage Abgängiges measurement signal is generated.

This Procedure requires that a person use the roof surface Help the described arrangement after a leak systematically searches what, depending on the extent of the testing roof surface with a very high expenditure of time connected is.

According to DE 10 2005 046 025 A1 a method for locating leaks on flat roofs is known, which is the in DE 199 21 556 C2 developed method and thus allows the simultaneous use of several people on the roof surface. Again, the high cost of time remains as a disadvantage.

According to DE 10 2005 049 651 A1 An arrangement for measuring the moisture on surfaces and a method for producing the same is known. In this arrangement, a plurality of humidity sensors, which are contacted with a network of electrically conductive compounds, on the surface z. B. a roof designed. The networked humidity sensors are controllable and readable at any time and can thus localize moisture penetration of the roof surface.

such known solutions based on introduced standard humidity sensors In any case, only occasionally the Capture moisture in the wall, roof and gutter construction. With These solutions are only partially possible in the Roof construction and thus penetrating into the insulation itself Capture water (eg in water channels, sooting). About that In addition, especially with large roof areas the arrangement to be used with a substantial material and associated costs.

OBJECT OF THE INVENTION

The The object of the invention is to provide a method for Detection and localization of moisture in thermally insulated metallic roof and gutter constructions.

Farther It is the object of the invention, an arrangement for execution to provide the method.

According to the invention the method of thermally insulated metallic Roof structures applied in their essential elements an electrically conductive, with the building construction connected tray, a designed on the tray vapor barrier, a designed on the vapor barrier insulation and a on the insulation resting metallic roof eaves skin consists. The roof outer skin is over with the tray electrically insulating support elements connected at a distance.

The metallic roof skin forms a first electrode of a plate capacitor and the metallic tray the second electrode of the plate capacitor. The dielectric of the plate capacitor is removed from the insulation, the vapor barrier and the support elements formed.

Of the plate capacitor formed in this way has in the dry State a reference value for the real and imaginary parts the impedance, wherein the value of the impedance at entry of Moisture in the roof construction compared to the reference value changed. The change in impedance is detected and evaluated. When moisture enters the thermal insulation the real part decreases and the imaginary part of the impedance increases against the 'dry' reference value.

The inventive method is characterized by the arrangement executed according to claim 2. In the dependent Subclaims are advantageous deviations and variants claims the inventive arrangement.

[Examples]

The Invention will become apparent from an embodiment described. The accompanying drawings show in

1 the execution of a roof construction according to the invention in a spatial representation, wherein parts of the roof structure are broken away to better represent the arrangement of the individual elements of the roof construction;

2 the basic principle of the arrangement according to the invention, shown on the cross section of a longitudinal view from the rear through the roof construction according to the invention, designed with means for measuring capacitance

3 a representation of the cross section of a side view through the roof and gutter construction according to the invention, designed with capacitance measuring means;

4 a schematic representation of the view of the roof and gutter construction according to the invention from above.

5 an electrical equivalent circuit diagram of a double-shell metal roof construction;

6 a simplified electrical equivalent circuit diagram of the double-shell metal roof construction according to 5 ,

In 1 an embodiment of the roof construction according to the invention is described, which generally with 1 is designated. This roof construction 1 is made by binders 2 worn on the side walls of the building at defined intervals.

The roof construction 1 sits on a metal tray 3 , which is preferably designed as a trapezoidal profile because of the associated high load capacity and on the binders 2 and firmly attached to them. The tray 3 is with a vapor barrier 4 covered, on which a firm insulation 5 is designed.

In order to meet the applicable requirements for thermal protection and energy conservation, a corresponding thickness of the insulating material is required. The use of only impact-resistant insulation 5 stand against their weight and their costs. For this reason, as insulation with appropriate thickness has a combination of shock-resistant insulation 5 and compressible insulation 6 , z. B. mineral wool proven.

The compressible insulation 6 is on the impact resistant insulation 5 designed in appropriate thickness. Above is the metallic roof skin 7 , which is formed from plates, which are connected at their longitudinal sides with each other by beading and folding with the necessary strength and waterproof.

Because the roof outer skin 7 with the compressible insulation 6 can not be assembled into a load-bearing composite, a support system is required, which consists of a plurality of support elements 8th is formed, which are arranged spaced from each other according to a predetermined, determined by the dimensions of the roof outer skin panels to be processed certain grid, and in this way a resilient bond between the tray 3 on the one hand and the roof outside skin 7 on the other hand is ensured with the intermediate functional layers.

Despite careful construction, can be described in the described bivalve thermally insulated metallic roof structures by convection and diffusion and damage in the roof outer skin 7 Moisture penetrate into the thermal insulation, which can lead to the complete failure of the function "thermal insulation".

The trays 3 are laid stress-free on the building construction and are shot either with the use of steel construction on the construction, or screwed with her. At the longitudinal edges of the trays 3 become all trays 3 screwed together to support each other. This screwing is done at a distance of 200-333 mm using a self-drilling screw 4.2 × 19 mm, or blind rivet 5.0 × 10 mm. The trays 3 derive the dead loads of the roof structure, as well as the snow and wind loads in the structure.

The vapor barrier 4 is applied depending on climatic conditions on the inside or outside of the thermal insulation. With the exception of cold stores, the vapor barrier in Europe is regularly on the inside of the tray 3 , The vapor barrier 4 to prevent both the diffusion and the convection of water vapor in the roof construction.

The thermal insulation is carried out in accordance with the applicable standard and in accordance with the ENEV "Energy Efficiency Ordinance". In the roofs mentioned the metallic Dachaussenhaut lies 7 directly on the compressible insulation 6 on to prevent the back condensation. The firm insulation 5 lies on the vapor barrier 4 and is slightly compressed to reduce voids.

The support elements 8th must with combined insulation the tray 3 and the roof outer skin 7 bring to a defined distance. The metallic tray 3 is a self-supporting profile sheet with spans of up to 3.75 m. In the case of impact-resistant insulation 5 All loads, such as snow and wind pressure, are covered by the roof outer skin 7 over the support elements 8th in the tray 3 transfer.

For the Sogverankerung be here by the impact-resistant insulation 5 support elements 8th turned pushes, by means of screws through the thermal insulation in the tray 3 are anchored. To avoid thermal bridges and electrical insulation to the tray 3 In these roof structures special electrically non-conductive thermal holder as support elements 8th used. This is an essential feature of the method according to the invention and the arrangement for detecting moisture in the thermal insulation.

The roof outer skin 7 usually consists of industrially prefabricated Stehfalz- or clamping rib profiles, which together and in the region of the support element 8th with the support profile of the support element 8th to be beaded.

The detection of penetrating moisture in large-area, thermally insulated metallic roof structures by convection, diffusion or damage to the roof outer skin 7 According to the invention is achieved in that the entire clam shell executed metal construction accordingly 2 is performed as an electric plate capacitor and the change in the impedance of this arrangement is measured or monitored.

The metallic tray 3 and the roof outer skin 7 represent the plates of the capacitor. In this case, according to the invention, the metallic tray 3 the first electrode of the plate capacitor with the electrical connection X, the metallic roof outer skin 7 the second electrode of the plate capacitor with the electrical connection B represents.

ε₀ –

Dielektrizitätskonstante des Vakuums

ε_r –

relative Dielektrizitätskonstante des Material (hier des Materials der Wärmedämmung)

The capacity of a lossless of the plate capacitor is calculated approximately to C top, roof = ε · A / d With ε = ε 0 ε r and

ε ₀ -

Dielectric constant of the vacuum

ε _r -

relative dielectric constant of the material (here the material of the thermal insulation)

C_Dach und R_{Dach :}

Kapazität und Verlustwiderstand der Wärmedämmung

C_ZK und R_ZK:

Kapazität und Verlustwiderstand der Zwischenkonstruktion

C_D und R_D:

Kapazität und Verlustwiderstand der Diffusionssperre

C_ST und R_ST:

Kapazität und Verlustwiderstand der Streukapazitäten (insbe sondere an den Randsektionen)

The electrically insulating vapor barrier, thermal insulation and intermediate structure represent the layered, lossy dielectric of the plate capacitor, as in 5 represented (electrical equivalent circuit diagram of a two-shell executed metal roof construction).

C _roof and R _{roof :}

Capacity and loss resistance of the thermal insulation

C _ZK and R _ZK :

Capacity and loss resistance of the intermediate structure

C _D and R _D :

Capacity and loss resistance of the diffusion barrier

C _ST and R _ST :

Capacity and loss resistance of the stray capacitors (in particular at the marginal sections)

The Capacity and the loss resistance of the diffusion barrier is in series with the capacity and the loss resistance the thermal insulation; Capacities and the Loss resistances of the intermediate construction and the stray capacities lie parallel to it.

6 shows the simplified equivalent circuit diagram.

Due to the very different sizes for the individual capacities and loss resistances accordingly 5 can be assumed as a simplified electrical equivalent circuit diagram of the parallel connection of a spare roof capacitance with a replacement loss resistance (insulation resistance) ( 6 ).

The impedance Z of a lossy (plate) capacitor as a parallel equivalent circuit is calculated as: Z top, roof = R top, roof - j / ωC top, roof or as an additive Y top, roof = G + jωC top, roof = 1 / Z top, roof

According to the invention, the plate capacitor thus executed is penetrated by an electric field variable in time and it can be determined with intact, dry thermal insulation, a characteristic value for the capacitor impedance Z _roof .

Heat insulating materials generally have a relative dielectric constant ε _r of 2-8; Water of about 81.

If moisture penetrates into the insulation, the capacity of the capacitor C _{roof will} increase and the electrical insulation resistance of the insulation R _roof will decrease.

The different humidity conditions in the thermal insulation are thus about the changes of the dielectric and electrical properties of the layered dielectric - vapor barrier and thermal insulation - the dam material detected.

The executed according to the invention Building construction is the sensor itself. About the impedance change the capacitive sensor can therefore the degree of humidity of the Interspace (thermal insulation, air layer) determined become.

All thermal insulation materials (and also the air itself) do not represent an ideal loss-free dielectric, so that a parallel connection of a lossless of the plate capacitor with a resistive (loss) resistance R _{roof is} set for the impedance of the sensor replacement circuit of the wall and roof capacity C _roof ,

For The location of the moisture is necessary, one of the two electrodes of the plate capacitor in each other electrically subdivided isolated sectors to be electrically independent form acting partial electrodes.

In the present example, the metallic roof outer skin 7 the roof construction 1 in appropriate roofing skin sectors 7 ₁ to 7 _n subdivided their capacities, then individually evaluated, in turn, a 'location' of moisture entry permit.

The electrical separation of the roof outer skin 7 in roofing skin sectors 7 ₁ to 7 _n According to the invention is achieved in that in the longitudinal joint connection a corresponding insulation film 15 in the Klemmrippprofil 9 is brought in and every roof sector 7 ₁ to 7 _n the roof outer skin 7 receives a separate electrical connection B ₁ to B _n . All partial capacities of the roof surface have the same coherent counter electrode (support shell 3 ) with the corresponding electrical connection X.

In usually go the electrically isolated on the fold-rib profile tracks (Sections) unthreatened from ridge to eaves. Track lengths of up to 100 m are at site production feasible, with transverse joints due to the low roof pitch be avoided.

The gutter structures according to the invention are according to 3 and 4 through clam-shell gutters 10 executed in their longitudinal extent in successive gutter sections 10 ₁ to 10 _n are divided. At the gutter sectors 10 ₁ to 10 _n the electrical insulation of the transverse joints of the gutter sectors z. B. by appropriate expansion joints 16 (vulcanized plastic-containing non-electrically conductive joints) realized.

The double-shell design of the gutter 10 is through the inner shell 11 and the outer shell 12 with the intermediate electrically non-conductive insulating layer 13 educated. The individual gutter sections 10 ₁ to 10 _n The electrical connections are assigned such that the inner shell 11 has a common electrical connection X, while the outer shell 12 according to the gutter sectors 10 ₁ to 10 _n is equipped with the electrical connections D ₁ to D _n .

Will the metallic, double-shell, heat-attenuated gutter construction in gutter sectors 10 ₁ to 10 _n divided, then are also on the impedance change of the sensor snow / snow loads on the roof outer skin 7 and stagnant water in the gutters 10 or soiling (leaves, sand) can be determined qualitatively and quantitatively.

This is inventively achieved in that both the individual capacities C ₁ to C _n to the tray 3 and the associated loss resistances R ₁ , R _{2 of} the roof outer skin sectors 7 ₁ to 7 _n as well as the capacities and loss resistances between the roof exterior skin sectors 7 ₁ to 7 _n the roof outer skin 7 - respectively the neighboring gutter sectors 10 ₁ to 10 _n -, So the stray capacitance and the loss resistance between the terminals D ₁ -D _n , here the tray 3 has no significant influence on the measurement result. This is inventively achieved in that all electrical connections D ₁ to D _{n of} the Dachaussenhautsektoren 7 ₁ to 7 _n the roof outer skin 7 and the tray 3 be passed with their electrical connection X via a floating or grounded multiplexer to a corresponding drive circuit.

According to the invention, the water level in the gutter 10 also by the stray capacity between the roof outer skin sectors 7 ₁ to 7 _n the roof outer skin 7 and the adjacent gutter sector 10 ₁ to 10 _n the gutter 10 be determined, wherein constructively the electrical insulation of roof outer skin 7 and gutter 10 must be provided. This is inventively achieved in that the intermediate structure 17 is designed electrically insulating (Kunststoffklipps) or the roof outer skin 7 additionally insulated from the intermediate structure by an electrical insulator (eg plastic plate).

following become the individual detection possibilities at a Hall roof, the roof construction and the associated Gutter shown:

Detection of moisture input in the roof construction

• Measurement and evaluation of capacity

  X-B ₁

  in roofing skin sector 7 ₁

  X-B ₂

  in roofing skin sector 7 ₂

  X-B _n

  in roofing skin sector 7 _n

  X-D ₁

  in gutter sector 10 ₁

  X-D ₂

  in gutter sector 10 ₂

  X-D _n

  in gutter sector 10 _n

Detection of snow and pollution on the roof construction

• Measurement and evaluation of capacity

  B ₁ -B ₂

  between roofing skin sector 7 ₁ and 7 ₂

  B ₂ -B ₃

  between roofing skin sector 7 ₂ and 7 ₃

  B _n-1 B _n

  between roofing skin sector 7 _n and 7 _n-1

Detection of snow, water and pollution in the gutter

• Measurement and evaluation of capacity

  D ₁ -B ₁

  between gutter sector 10 ₁ and roofing skin sector 7 ₁

  D ₂ -B ₂

  between gutter sector 10 ₂ and roofing skin sector 7 ₂

  D _n -B _n

  between gutter sector 10 _n and roofing skin sector 7 _n or

  D ₁ -D ₂

  between gutter sector 10 ₁ and 10 ₂

  D ₂ -D ₂

  between gutter sector 10 ₂ and 10 ₃

  D _n-1 D _n

  between gutter sector 10 _n-1 and 10 _n

Of the Advantage of the solution according to the invention exists in that with little effort an online monitoring is great Roof areas in particular of industrial halls with regard to in the roof construction of incoming moisture and on the roof and in the gutter lying snow loads and foreign bodies can be operated. Especially with regard to the material Values that are contained in halls is the avoidance of Damage in the roof structure due to incoming moisture or moisture Too much snow load is a primary advantage of Invention.

1

Roof construction

2

Binder,

3

Tray,

4

Vapor barrier,

5

Shatter-proof Insulation,

6

compressible Insulation,

7

Roof outer skin,

7 ₁ to 7 _n

Roof outer skin sector,

8th

Support element,

9

Clamping profile,

10

Gutter,

10 ₁ to 10 _n

Gutter sector

11

Inner hull,

12

Outer shell,

13

insulating layer,

14

Water,

15

Insulation film,

16

expansion joint,

17

Between design,

X

electrical Connection individual capacities,

B ₁ to B _n

electrical Connection individual capacities,

D ₁ to D _n

electrical Connection individual capacities,

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19921556 C2 [0002, 0005]
• DE 102005046025 A1 [0005]
• DE 102005049651 A1 [0006]

Claims (8)

Method for detecting moisture in thermally insulated metallic roof structures ( 1 ), whereby the roof construction ( 1 ) in its essential elements of an electrically conductive, connected to the building structure supporting shell ( 3 ), one on the tray ( 3 ) designed vapor barrier ( 4 ), one on the vapor barrier ( 4 ) designed insulation ( 5 ) and one on the insulation ( 5 ) resting roof skin ( 7 ) and the roof outer skin ( 7 ) with the tray ( 3 ) via electrically insulating support elements ( 8th ) is spaced apart, characterized in that the roof outer skin ( 7 ) a first electrode of a plate capacitor and the tray ( 3 ) form the second electrode of the plate capacitor and the dielectric of the plate capacitor from the insulation ( 5 ), the vapor barrier ( 4 ) and the support elements ( 8th ), and the plate capacitor formed in this way has a reference value for the impedance in the dry state, wherein the value of the impedance when moisture enters the roof construction ( 1 ) is changed compared to the reference value and the change in the impedance is detected and evaluated. Arrangement for detecting moisture in thermally insulated metallic roof structures ( 1 ), whereby the roof construction ( 1 ) in its essential elements of an electrically conductive, connected to the building structure supporting shell ( 3 ), one on the tray ( 3 ) designed vapor barrier ( 4 ), one on the vapor barrier ( 4 ) designed insulation ( 5 ) and one on the insulation ( 5 ) resting roof skin ( 7 ) and the roof outer skin ( 7 ) with the tray ( 3 ) via electrically insulating support elements ( 8th ) is spaced apart, characterized in that the roof outer skin ( 7 ) a first electrode of a plate capacitor and the tray ( 3 ) form the second electrode of the plate capacitor and the dielectric of the plate capacitor from the insulation ( 5 ), the vapor barrier ( 4 ) and the support elements ( 8th ), the plate capacitor formed in this way has a reference value for the impedance in the dry state, and the value of the impedance when moisture is introduced into the roof construction ( 1 ) Can be changed in comparison to the reference value and the change of the impedance means for detection, location and evaluation can be fed. Arrangement according to claim 2, characterized in that the roof outer skin ( 7 ) in a plurality of mutually electrically isolated Dachaussenhautsektoren ( 7 ₁ to 7 _n ), each of the roof outer skin sectors ( 7 ₁ to 7 _n ) as a partial, electrically self-acting partial electrode through the roof outer skin ( 7 ) formed first electrode of the plate capacitor, which with the through tray ( 3 ) formed second electrode of the plate capacitor is in operative relationship. Arrangement according to claim 2 and 3, characterized in that the roof construction ( 1 ) a gutter ( 10 ), which consists of an inner shell ( 11 ) and an outer shell ( 12 ) with an interposed electrically insulating insulation ( 13 ) is formed, wherein the inner shell ( 11 ) Part of the first electrode of the plate capacitor and the outer shell ( 12 ) Is part of the second electrode of the plate capacitor, wherein the outer shell ( 12 ) with the neighboring roof skin sections ( 7 ₁ to 7 _n ) via an electrically insulating intermediate construction ( 17 ), and the gutter ( 10 ) in their longitudinal extent in a plurality of mutually insulated gutter sectors ( 10 ₁ to 10 _n ) is divided. Arrangement according to claim 2 to 4, characterized in that the between the Dachaussenhautsektionen ( 7 ₁ to 7 _n ) on the one hand and the tray ( 3 ) On the other hand, existing capacities via corresponding electrical connections (B ₁ to B _n ) or (X) via a floating or grounded multiplexer detection and evaluation of the measured variables are supplied. Arrangement according to claim 2 to 4, characterized in that between the outer shell ( 12 ) of the gutter sections ( 10 ₁ to 10 _n ) on the one hand and the inner shell ( 11 On the other hand, existing capacities via corresponding electrical connections (D ₁ to D _n ) or (X) via a floating or grounded multiplexer detection and evaluation of the measured variables are supplied. Arrangement according to claim 2 to 4, characterized in that between the outer shell ( 12 ) of the gutter sections ( 10 ₁ to 10 _n ) on the one hand, and the adjacent roof outer skin sections ( 7 ₁ or 7 _n ) On the other hand existing capacity via corresponding electrical connections (D ₁ to D _n ) or (B ₁ to B _n ) via a floating multiplexer detection and evaluation of the measured variables can be fed. Arrangement according to claim 2 to 4, characterized in that between adjacent Dachaussenhautsektionen ( 7 ₁ - 7 ₂ to 7 _n-1 - 7 _n ) existing capacitances via corresponding electrical connections (D ₁ -D ₂ to D _n-1 -D _n ) via a floating multiplexer detection and evaluation of the measured variables can be fed.