planning:refurbishment_with_passive_house_components:thermal_envelope:airtightness
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| planning:refurbishment_with_passive_house_components:thermal_envelope:airtightness [2019/01/10 11:39] – [Calculation of the volume] cblagojevic | planning:refurbishment_with_passive_house_components:thermal_envelope:airtightness [2024/07/25 15:10] (current) – [See also] yaling.hsiao@passiv.de | ||
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| - | [[http:// | + | ====== Airtightness and airtightness measurement ====== |
| + | |||
| + | ===== Basic and airtightness in existing building===== | ||
| - | ====== Airtightness in old buildings ====== | ||
| ===== Airtightness – how and why? ===== | ===== Airtightness – how and why? ===== | ||
| - | There are many disadvantages of air flowing in through joints and gaps in the building envelope. A large percentage of building damage is caused by leaks in the building envelope. | + | There are many disadvantages of air flowing in through joints and gaps in the building envelope. A large percentage of building damage is caused by leaks in the building envelope. Sound insulation is reduced, drafts cause discomfort for occupants and there are high heat losses. That is why airtightness standards have been set for many years and why we still have them in current regulations. |
| It is still widely beleived that poor airtightness ensures good ventilation in dwellings. However air movement is greatly dependent on outside wind speeds and the stack effect within the building (where warm air tends to rise). There are substantial drafts in poorly airtight old buildings even at moderate wind speeds but during periods of mild and calm weather air flows are inadequate. The air flow rate is too variable to maintain a consistant hygienic level of air exchange and high ventilation heat losses are inevitable. | It is still widely beleived that poor airtightness ensures good ventilation in dwellings. However air movement is greatly dependent on outside wind speeds and the stack effect within the building (where warm air tends to rise). There are substantial drafts in poorly airtight old buildings even at moderate wind speeds but during periods of mild and calm weather air flows are inadequate. The air flow rate is too variable to maintain a consistant hygienic level of air exchange and high ventilation heat losses are inevitable. | ||
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| In particular, airtightness has the following advantages: | In particular, airtightness has the following advantages: | ||
| + | |||
| * prevention of moisture related building damage | * prevention of moisture related building damage | ||
| + | |||
| * prevention of drafts and cold feet | * prevention of drafts and cold feet | ||
| + | |||
| * prevention of high heat losses due to infiltration | * prevention of high heat losses due to infiltration | ||
| + | |||
| * improvement of sound insulation | * improvement of sound insulation | ||
| + | |||
| * improved indoor air quality (e.g. prevention of pollution with radon from the ground) | * improved indoor air quality (e.g. prevention of pollution with radon from the ground) | ||
| An adequate level of airtightness is the basis for: | An adequate level of airtightness is the basis for: | ||
| + | |||
| * the use of a variable demand-oriented ventilation (functioning with directed air flows) and | * the use of a variable demand-oriented ventilation (functioning with directed air flows) and | ||
| + | |||
| * the effectiveness of the thermal insulation without air flowing through it | * the effectiveness of the thermal insulation without air flowing through it | ||
| Two similar terms should be clarified: the __wind__tightness of a building component protects it from external air flowing in through the thermal insulation, which would otherwise impair the insulating effect and lead to increased energy consumption. This should not be confused with __air__tightness that is being discussed here, which is used for the movement of air through the building envelope, from the inside towards the outside or vice versa. | Two similar terms should be clarified: the __wind__tightness of a building component protects it from external air flowing in through the thermal insulation, which would otherwise impair the insulating effect and lead to increased energy consumption. This should not be confused with __air__tightness that is being discussed here, which is used for the movement of air through the building envelope, from the inside towards the outside or vice versa. | ||
| - | __Wind__tightness is completely different from __air__tightness, | + | __Wind__tightness is completely different from __air__tightness, |
| - | \\ | + | |
| ===== Testing the airtightness ===== | ===== Testing the airtightness ===== | ||
| - | The airtightness of a building can be measured by means of an air pressure test (airtightness test or “blower door test”) which determines the overall remaining leakage of a building. | + | The airtightness of a building can be measured by means of an air pressure test (airtightness test or “blower door test”) which determines the overall remaining leakage of a building. A fan is installed into a door or window to create a negative pressure in the whole house. The fan has a measuring device which gives the air flow rate for the pressure being tested. Flow rates are recorded for pressure differences at several points between 10 and 70 Pascals (Pa) negative pressure. The value at 50 Pa is calculated from the range of readings. The whole process is then repeated using a range of positive pressures [[.: |
| - | \\ | + | \\ |
| - | |{{ : | + | |{{ : |
| - | |//**Figure 1: Basic measurement setup for testing airtightness; | + | |
| - | \\ | + | |
| - | The negative and positive air pressure test results at 50 Pa are then averaged to give a single result, the leakage rate n< | + | |
| - | Pressure test results of old buildings that have not been modernised are often in the range between 3 and 6 h< | + | |//**Figure |
| - | With professional planning and implementation of the airtightness measures using the appropriate materials, permanently high airtightness values of the building can be expected | + | Pressure test results of old buildings that have not been modernised are often in the range between 3 and 6 h< |
| - | \\ | + | |
| + | With professional planning and implementation of the airtightness measures using the appropriate materials, permanently high airtightness values of the building can be expected ([[.: | ||
| ===== Airtightness measurement in refurbishment projects ===== | ===== Airtightness measurement in refurbishment projects ===== | ||
| - | Depending on the refurbishment project (partial or complete refurbishment), | + | Depending on the refurbishment project (partial or complete refurbishment), |
| - | __Example: | + | __Example: |
| + | |||
| + | At the same time, the initial value of the project is documented which will then be used to ascertain the improvement after implementation of the modernisation measures. Even during the initial measurement for the planning, the building components that will represent the airtight layer must be specified. If specific areas prove to be airtight enough (e.g. intact interior plaster), they can be incorporated into the new concept. \\ | ||
| - | At the same time, the initial value of the project is documented which will then be used to ascertain the improvement after implementation of the modernisation measures. Even during the initial measurement for the planning, the building components that will represent the airtight layer must be specified. If specific areas prove to be airtight enough (e.g. intact interior plaster), they can be incorporated into the new concept.\\ | ||
| - | \\ | ||
| ==== Notes for implementation ==== | ==== Notes for implementation ==== | ||
| - | If a particularly low level of airtightness is expected for a building (many leaks) or if the building is particularly large, the pressure test can be carried out using several blower fans. In accordance with the [[planning: | + | If a particularly low level of airtightness is expected for a building (many leaks) or if the building is particularly large, the pressure test can be carried out using several blower fans. In accordance with the [[.: |
| In order to reduce the volume to be tested in large buildings it is possible to divide the building into several zones and test them one after another. It must be made sure that dividing the building is technically feasible. In most buidlings it will not be possible to achieve a perfect airtight separation of the zones. In this case the leakage between the zones will affect the measured value. To prevent this leackage the zones that are not tested at that time can be pressurized by another fan to the same preasure as the tested zone (guard-zone-measurement). Because of the huge extra effort dividing a building into several zones and testing them seperately this method is only recommended in special situations. | In order to reduce the volume to be tested in large buildings it is possible to divide the building into several zones and test them one after another. It must be made sure that dividing the building is technically feasible. In most buidlings it will not be possible to achieve a perfect airtight separation of the zones. In this case the leakage between the zones will affect the measured value. To prevent this leackage the zones that are not tested at that time can be pressurized by another fan to the same preasure as the tested zone (guard-zone-measurement). Because of the huge extra effort dividing a building into several zones and testing them seperately this method is only recommended in special situations. | ||
| - | Measurements should take place in the state of use. This means that during the preparation of the building for the test, only those openings should be sealed which would normally be closed tight. Supply air openings for a non-room-sealed fireplace (e.g. apartment heating or coal stove) may not be closed or sealed for the test. These openings are essential during operation and always remain open and therefore influence the airtightness of the building and its thermal assessment. | + | Measurements should take place in the state of use. This means that during the preparation of the building for the test, only those openings should be sealed which would normally be closed tight. Supply air openings for a non-room-sealed fireplace (e.g. apartment heating or coal stove) may not be closed or sealed for the test. These openings are essential during operation and always remain open and therefore influence the airtightness of the building and its thermal assessment. |
| + | |||
| + | During the measurement it is always advisable to carry out a series of negative AND excess pressures so that the building’s performance can be better represented and to increase the measurement accuracy. A major part of the time is required for the preparation of the building and for detecting leaks; in contrast, the actual test normally takes only about 30 to 40 minutes, therefore saving time here wouldn’t be appropriate. \\ | ||
| - | During the measurement it is always advisable to carry out a series of negative AND excess pressures so that the building’s performance can be better represented and to increase the measurement accuracy. A major part of the time is required for the preparation of the building and for detecting leaks; in contrast, the actual test normally takes only about 30 to 40 minutes, therefore saving time here wouldn’t be appropriate.\\ | ||
| - | \\ | ||
| ==== Calculation of the volume ==== | ==== Calculation of the volume ==== | ||
| - | The volumetric flow of the leakage V< | + | The volumetric flow of the leakage V< |
| - | <WRAP center 60%> | + | <WRAP center 60%> |
| - | < | + | |
| - | \Large{n_{50} = \dfrac{V_{50}}{V} \: [\dfrac{1}{h}]} | + | |
| - | </ | + | |
| - | </ | + | |
| This does not depend on the size of the building and can be used for comparisons between buildings or for comparisons before and after the modernisation. The actual heated volume of the building is the result of the heated living space multiplied by the clear room height. | This does not depend on the size of the building and can be used for comparisons between buildings or for comparisons before and after the modernisation. The actual heated volume of the building is the result of the heated living space multiplied by the clear room height. | ||
| - | The volume in a wall that results from the installation of a window or a door is not taken into account for the calculation of the building volume. For suspended ceilings only the clear measurement up to the suspended ceiling is considered. This always applies regardless of how airtightly the suspension has been carried out. Among other things, this stipulation according to [[planning:refurbishment_with_passive_house_components:thermal_envelope: | + | The volume in a wall that results from the installation of a window or a door is not taken into account for the calculation of the building volume. For suspended ceilings only the clear measurement up to the suspended ceiling is considered. This always applies regardless of how airtightly the suspension has been carried out. Among other things, this stipulation according to [[.:airtightness:special_features_in_modernisations#literature|[FliB 2002] ]] in addition to the [[.:airtightness:special_features_in_modernisations#literature|[EN 13829] ]] standard facilitates the test in old buildings for which no detail plans are available. |
| Beams, visible rafters etc. are not deducted. The actual size of the volumes under sloping ceilings etc. are taken into account. If there are staircases inside the airtight layer these are also added with their base area and clear height without considering the stairs themselves (i.e. as a simplification the volume of the steps is not subtracted from the building volume). | Beams, visible rafters etc. are not deducted. The actual size of the volumes under sloping ceilings etc. are taken into account. If there are staircases inside the airtight layer these are also added with their base area and clear height without considering the stairs themselves (i.e. as a simplification the volume of the steps is not subtracted from the building volume). | ||
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| The volume must be determined by the inspector himself and must be documented comprehensibly, | The volume must be determined by the inspector himself and must be documented comprehensibly, | ||
| - | For large buildings (greater than ca. 4000 m³) it is always easier to implement low n< | + | For large buildings (greater than ca. 4000 m³) it is always easier to implement low n< |
| - | <WRAP center 60%> | + | <WRAP center 60%> |
| - | < | + | |
| - | \Large{q_{50} = \dfrac{V_{50}}{A} \: [\dfrac{m³}{hm²}]} | + | |
| - | </ | + | |
| - | </ | + | |
| The q< | The q< | ||
| - | The calculation for the envelope surface is given in [[planning: | + | The calculation for the envelope surface is given in [[.: |
| - | \\ | + | |
| - | |{{:picprivate: | + | |
| - | |//**Figure 2: Interrelation of the q< | + | |
| - | \\ | + | |
| - | | ^V\\ [m< | + | |
| - | ^Building 1| | + | |
| - | ^Building 2| | + | |
| - | ^Building 3| 4 080 | + | |
| - | ^Building 4| 9 000 | + | |
| - | ^Building 5| 25 200 | + | |
| - | ^Building 6| 62 500 | + | |
| - | //**Table 1: Data for the 6 buildings shown in Figure 2.**//\\ | + | |
| - | \\ | + | |
| - | ===== Basic principles for planning airtightness | + | |//**Figure 2: Interrelation of the q< |
| + | ^Building 1| 200 | 210 | 1.05 | **0.6** | ||
| + | ^Building 2| 360 | 312 | 0.87 | **0.6** | ||
| + | ^Building 3| 4 080 | 1 568 | 0.38 | **0.6** | ||
| + | ^Building 4| 9 000 | 2 820 | 0.31 | **0.6** | ||
| + | ^Building 5| 25 200 | 5 500 | 0.22 | **0.6** | ||
| + | ^Building 6| 62 500 | 10 000 | 0.16 | **0.6** | ||
| + | |||
| + | There are two central planning fundamentals for implementing an airtight building envelope (based on [[.: | ||
| + | \\ | ||
| + | ^1. The “pencil rule”: it must be possible to trace the airtight layer of the envelope in the plan (for each building section) using a pencil without lifting the pencil – except for any planned ventilation openings. ^ \\ | ||
| + | \\ | ||
| + | ^2. There must be only one single uninterrupted airtight layer. Leaks CANNOT be remedied by another airtight layer before or after the first one (e.g. double lip seals at windows, vestibule door behind the front door). A comparison to illustrate this point: water won’t stop leaking from a bucket with a leak if the bucket is placed inside another bucket with a leak. ^ \\ | ||
| + | \\ | ||
| + | Besides the basic principles, the following guidelines are helpful | ||
| - | There are two central planning fundamentals for implementing an airtight building envelope (based on [[planning: | ||
| - | \\ | ||
| - | ^1. The “pencil rule”: it must be possible to trace the airtight layer of the envelope in the plan (for each building section) using a pencil without lifting the pencil – except for any planned ventilation openings. | ||
| - | \\ | ||
| - | ^2. There must be only one single uninterrupted airtight layer. | ||
| - | \\ | ||
| - | Besides the basic principles, the following guidelines are helpful for successful planning of the airtightness – whether for a new construction or for a refurbishment of an old building (based on [[planning: | ||
| * **simplicity**: | * **simplicity**: | ||
| - | * preferably **large uniform** areas with a simple basic construction | + | * preferably **large uniform** |
| * selection of reliable and proven basic construction techniques – it is not necessary to develop completely new or exceptional sealing systems | * selection of reliable and proven basic construction techniques – it is not necessary to develop completely new or exceptional sealing systems | ||
| - | * **adherence to common principles** when planning different connections | ||
| - | * in principle, any **penetrations** of the sealing envelope should be avoided or minimised\\ | ||
| - | \\ | ||
| - | ===== Planning basics ===== | + | * **adherence to common principles** |
| + | * in principle, any **penetrations** | ||
| When planning an airtight building, three construction elements should be specified and taken into consideration: | When planning an airtight building, three construction elements should be specified and taken into consideration: | ||
| - | - construction techniques for airtightness in **standard surfaces**, | ||
| - | - airtight **connections** of building components (along a “line”), | ||
| - | - airtightness of **penetrations** through building components or at the corners where more than two components meet together (at a “point”).\\ | ||
| - | \\ | ||
| - | ==== Airtightness in surfaces ==== | + | - construction techniques for airtightness in **standard surfaces**, |
| + | - airtight **connections** | ||
| + | - airtightness of **penetrations** | ||
| - | During the planning stage, the airtight layer for each external building component must be clearly specified. | + | During the planning stage, the airtight layer for each external building component must be clearly specified. It does not matter which layer of a component (load-bearing structure, interior cladding, etc.) is used as an airtight layer, but care should be taken that it can be connected as easily and securely with the airtight layers of the adjacent building components as possible. |
| - | The determination of the precisely defined airtight layer depends on the materials used, i.e. the structure of the walls, roof or floor. | + | The determination of the precisely defined airtight layer depends on the materials used, i.e. the structure of the walls, roof or floor. Common construction materials have varying degrees of permeability. Four material groups can be used to implement an airtight layer: |
| - PE sheets/ | - PE sheets/ | ||
| - Interior plaster | - Interior plaster | ||
| - Concrete | - Concrete | ||
| - | - Wood-based panels\\ | + | - Wood-based panels \\ \\ Airtightness concepts of all kinds usually consist of a combination of these materials. In principle it should be possible to use these materials without any joints or to seal the joints permanently without great effort. |
| - | \\ | + | |
| - | Airtightness concepts of all kinds usually consist of a combination of these materials. | + | |
| Interior plaster is normally used as the airtight layer in **solid constructions**. A continuous layer of plaster is necessary because an unplastered brick wall generally isn’t airtight. The uninterrupted interior plaster should be applied from the unfinished floor (before applying the screed!) right up to the unfinished ceiling and joined together tightly. It is important to ensure that “invisible” areas, like those behind stairs and prewall installations in bathrooms, are correctly plastered. This is necessary for an airtight application of the plaster and not for decorative reasons. For such areas, it has proved to be practicable if a smooth layer of cement is applied on the unfinished surface as a “preliminary layer”. Force-fitted interconnected concrete elements are the only supporting structures that are airtight by themselves. | Interior plaster is normally used as the airtight layer in **solid constructions**. A continuous layer of plaster is necessary because an unplastered brick wall generally isn’t airtight. The uninterrupted interior plaster should be applied from the unfinished floor (before applying the screed!) right up to the unfinished ceiling and joined together tightly. It is important to ensure that “invisible” areas, like those behind stairs and prewall installations in bathrooms, are correctly plastered. This is necessary for an airtight application of the plaster and not for decorative reasons. For such areas, it has proved to be practicable if a smooth layer of cement is applied on the unfinished surface as a “preliminary layer”. Force-fitted interconnected concrete elements are the only supporting structures that are airtight by themselves. | ||
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| For **lightweight or mixed constructions**, | For **lightweight or mixed constructions**, | ||
| - | A reliable solution for lightweight constructions is the “double use” of the vapour barrier [[planning: | + | A reliable solution for lightweight constructions is the “double use” of the vapour barrier [[.: |
| - | \\ | + | |
| ==== Linear airtight connections ==== | ==== Linear airtight connections ==== | ||
| - | If basic airtight constructions have been chosen for the different building components, the airtight connections between the building components must also be carefully planned, because this is where significant leaks are often found later on. Even a compact single-family house with a simple layout can be used as an example: depending on the type of construction, | + | If basic airtight constructions have been chosen for the different building components, the airtight connections between the building components must also be carefully planned, because this is where significant leaks are often found later on. Even a compact single-family house with a simple layout can be used as an example: depending on the type of construction, |
| - | In the publication [[planning:refurbishment_with_passive_house_components:thermal_envelope: | + | In the publication [[.:airtightness:special_features_in_modernisations#literature|[Peper 2008] ]], it was explained that good planning for airtightness begins with the identification of the airtight layers of the building components. The following example is given there to illustrate this point. |
| === Example: Installation of a window or door frame in an external masonry wall === | === Example: Installation of a window or door frame in an external masonry wall === | ||
| - | //**Common errors:**// the attempt is made to connect the frame “tightly“ with the bare brickwork using construction foam, filling, sealing tape or adhesive tape. This will not succeed; it is not a question of the materials used, but rather an error in the specification of the airtightness layers. In an external masonry wall, the brickwork is not the airtightness layer. The whole brickwork area is interconnected through a network of gaps and hollow spaces containing air – in other words, the brickwork is an air conducting layer. Therefore the airtight layer of a component abutting a brickwork wall cannot be connected to the bare brickwork; instead, it must be connected to the airtight layer – which is usually the interior plaster.\\ | + | //**Common errors: |
| - | \\ | + | |
| - | //**Correct method: | + | - Identification of the airtight layers of the components to be connected, these are for example: \\ For window frames: the inside surface of frames. \\ For external brickwork: the interior plaster extending into the reveal. |
| - | - Identification of the airtight layers of the components to be connected, these are for example:\\ For window frames: the inside surface of frames.\\ For external brickwork: the interior plaster extending into the reveal. | + | |
| - Airtight connection of these airtight layers with each other. | - Airtight connection of these airtight layers with each other. | ||
| - | Since the frame and plaster can move in relation to each other as a result of the different thermal expansion coefficients and mechanical strain (weight of window or door wing when opened), the airtight connection must be able to accommodate relative movements of up to 2 mm without tearing. Therefore direct plastering in of the frame is not possible. Better solutions would be: | ||
| - | **I.** Adhesive tape applied securely to the plaster which is stuck to the frame and can be plastered over later (fleece-laminated adhesive tape).\\ | + | Since the frame and plaster |
| - | **II.** A plastic plastering strip, one side of which has a a flexible airtight sealing insert with enough give (≥ 2 mm) which is glued to the window frame, the other side of which is rigid and is plastered over inside the interior plaster.\\ | + | |
| - | **III.** A plaster end-strip which is applied at a distance | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 3: The possibilities (see above (I) to (III)) for a permanently airtight\\ connection | + | |
| - | \\ | + | |
| - | Based on the basic principle given in the example described in [[planning: | + | |
| - | \\ | + | |
| - | ===== Penetrations of the airtight layer ===== | + | |
| - | It is obvious that after all the efforts for a continuous airtight layer, any penetrations must be avoided or minimised. In this context, it is often forgotten that this plainly constitutes a planning task. It should not be left to the construction workers | + | **I.** Adhesive tape applied securely |
| - | Therefore, in new constructions as well as in modernisations, | + | |//**Figure 3: The possibilities (see above (I) to (III)) |
| - | * Preliminary planning | + | |
| - | * Coordination | + | |
| - | | + | |
| - | | + | |
| - | \\ | + | |
| - | ===== Special features of modernisations ===== | + | |
| - | It has already been analysed in [[planning: | + | \\ Based on the basic principle |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 4: A continuous airtight envelope in an old building?\\ Where exactly can it be located? (Source: | + | |
| - | \\ | + | |
| - | In solid constructions requiring modernisation, | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 5: Problematic area in an airtight layer on the inside: the wood beam ceiling;\\ subsequent sealing is only possible by including the planks at the edge – with\\ | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 6: Absence of interior plaster in the exposed area of the wood beam\\ ceiling in a modernisation project [[planning: | + | |
| - | \\ | + | |
| - | During the complete refurbishment of a building built in the Wilhelminian style, some of the beam heads had to be replaced. For this reason the floor near the external | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 7: completely exposed floor construction | + | |
| - | \\ | + | |
| - | ==== Integration | + | ===== Penetrations |
| - | The refurbishment project with interior insulation shown in //**Figure 7**// is an example for the integration of beam heads: | + | It is obvious that after all the efforts for a continuous |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |{{ : | + | |
| - | |//**Figure 8: Airtight integration of the beam heads implemented as steel braces\\ when using calcium silicate interior insulation boards.\\ __Above:__ incorrect bonding to the calcium silicate board which does NOT\\ constitute the airtight layer.\\ __Below__: correct method connecting the steel brace with the airtight layer of\\ plaster ([[planning: | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 9: Beam heads implemented as steel braces before (left) and after (right) installation allready shown in Figure 8.\\ The airthigt layer and calcium silicate interior insulation boards | + | |
| - | \\ | + | |
| - | ==== Interrupted airtight layer ==== | + | |
| - | Problems arise when the airtight layers of the different areas – usually the different storeys – cannot be connected with each other. In this case, as mentioned before, good values for the airtightness CANNOT be expected | + | Therefore, in new constructions |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 10: Interruption of a continuous airtight layer by the wood beam ceiling. For the connection between the airtight layer of\\ the roof area and the wall area, either a connection “through” the ceiling can be chosen, or the whole roof area must be borde-\\ red airtightly from above and below, up to the opening for the stairs for example [[planning: | + | |
| - | \\ | + | |
| - | There are also attempts for solving the problems by extending the membrane from the roof area (or the knee wall) in the floor build-up for a certain distance into the room (see //**Figure 11**// and //**Figure 12**//), instead of directly connecting the two layers. The purpose is to sufficiently decrease the air permeability of the wall/floor area so that the necessary level of airtightness can be achieved. The longer distance is expected to increase the air permeability resistance. Even if screed is later applied which weighs down the membrane in the floor build-up, there will still be countless leakage paths in the area of the uppermost ceiling (see blue arrows in //**Figure 12**//). Because the brickwork generally has inadequate airtightness, | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 11: Airtight membrane laid in the area of the knee wall during the\\ modernisation of a Wilhelminian building in Hamburg. The membrane is\\ extended 50 cm into the room in the floor build-up [[planning: | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 12: Detail of the knee wall area in Figure 11. The red arrows show the\\ two airtight layers which are not connected. The blue arrows indicate the air\\ flow paths that remain (leaks) [[planning: | + | |
| - | \\ | + | |
| - | ==== Alternative: | + | |
| - | In the case of exterior insulation, no-one wishes to make changes to the inside of their home, therefore any measures in the area of the wood beam ceiling are usually undesirable. In order to achieve | + | |
| - | * new plaster all over the old plaster. | + | * Preliminary planning |
| - | * Overall application of the adhesive for attaching the compound insulation system on the old exterior plaster | + | |
| - | By placing the airtight layer at the exterior face of the brick walls, the envelope can enclose the wood beam ceiling area without problem. | + | * Coordination |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 13: | + | |
| - | \\ | + | |
| - | ==== Wall-to-basement connection ==== | + | |
| - | Near the rising brick wall of the basement, an area remains where the airtight layer is not continuously connected (//**Figure 14**//). What counts here is, how airtight the masonry is (checked area). Perfect results should not be expected. For the actual project in Nuremberg, the critical area being considered here turned out to be astonishingly airtight in practice. However, this result certainly cannot be transferred to modern masonry (with open joints) and vertically perforated masonry. For old solid brick masonry the cumulative airtightness effect through several metres of the wall may be sufficient.\\ | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 14: A possible weak spot in an external airtight\\ layer at the transition of the external wall to the base-\\ ment ceiling ([[planning: | + | |
| - | \\ | + | |
| - | ==== Wall-to-roof and wall-to-uppermost ceiling connection ==== | + | |
| - | + | ||
| - | Above in //**Figure 4**//, the course of the airtight layer can be seen on the old building surface. In the roof area the knee wall must be enclosed in the airtight layer.\\ | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 15: | + | |
| - | \\ | + | |
| - | If the uppermost ceiling is executed as a concrete ceiling it will usually be sufficiently airtight. However, a wood beam ceiling is extremely non-airtight. It is quite difficult to strengthen the ceiling soffit on the inside of the airtight layer, even for the uppermost ceiling. | + | |
| - | + | ||
| - | Achieving an uninterrupted airtight layer is made difficult by the comparatively complicated penetration details in the uppermost ceiling that are typical for old buildings. | + | |
| - | + | ||
| - | An example of such a penetration is shown in //**Figure 16**//: reinforcing braces for the roof rise from the uppermost ceiling. If the airtight layer is situated on the floor boards, these braces will penetrate the airtight layer. Since the beams also have cracks in them, it will not be easy to ensure an airtight penetration here. //**Figure 16**// also shows a drawing for the solution to this problem and pictures of the details. The following instructions were devised for the demonstration project in Nuremberg: | + | |
| - | \\ | + | |
| - | **I.** The surrounding area of the penetration should be cleaned. | + | |
| - | + | ||
| - | **II.** A strip of membrane is placed loosely around the penetration, | + | |
| - | + | ||
| - | **III.** 10 mm high battens | + | |
| - | + | ||
| - | **IV.** Wide cracks in the floor boards, beams and between the beams and floor boards or walls are plugged with fibres (or paper) so that the plaster used for (**V**) does not flow away. | + | |
| - | + | ||
| - | **V.** The areas prepared thus are poured with liquid gypsum, minimum height 5 mm. The materials used to plug the cracks (**IV**) should not stick out of the gypsum. The gypsum should easily infiltrate all the cracks in the wood beams etc.. It must overlap the membrane strips by at least 30 mm. | + | |
| - | + | ||
| - | **VI.** If the battens in (**III**) are in the way, they can be removed again after the gypsum has set; but they can also remain as they are. | + | |
| - | **VII.** The airtight membrane that is laid on the ceiling | + | |
| - | **VIII.** Thermal insulation must be applied on the upper side of the airtight layer.\\ | + | ====== See also ====== |
| - | \\ | + | |
| - | The advantage of using gypsum is that it does not shrink when it hardens, it expands slightly instead. In place of gypsum, other hardening sealing materials can also be used which are initially fluid and are either elastic or do not shrink.\\ | + | |
| - | \\ | + | |
| - | |{{ : | + | |
| - | |//**Figure 16: Sealing in of braces penetrating the airtight layer of the topmost ceiling.\\ Above left: initial state with a brace penetrating the ceiling. Above centre: poured\\ gypsum is ready. Above right: The gypsum flows into all cracks. Below: drawing\\ showing this (principle [[planning: | + | |
| - | \\ | + | |
| - | This method represents a good and practicable solution for an airtight connection in a horizontal airtight layer. However, a very thin layer of plaster may break. Another possibility is to connect the membrane with the beam using an elastic sealing mass which can also be injected into large cracks and gaps of the beams.\\ | + | |
| - | \\ | + | |
| - | ===== See also ===== | + | |
| - | [[planning: | + | [[planning: |
| - | ===== Literature ===== | + | [[.: |
| - | **[EN 13829]** EN 13829: Wärmetechnisches Verhalten von Gebäuden. Bestimmung der Luftdichtheit von Gebäuden. Differenzdruckverfahren\\ | + | [[.:improving_thermal_bridges_and_airtightness_in_existing_buildings|]] |
| - | (Thermotechnical behaviour of buildings. Differential pressure method) (ISO 9972:1996, modified), German version EN 13829:2000, DIN Deutsches Institut für Normung e.V., Beuth-Verlag, | + | |
| - | \\ | + | |
| - | **[EnSan 2008]** EnSan (Energetische Verbesserung der Bausubstanz) Abschlussbericht vom Projekt „Hamburg, Kleine Freiheit 46-52\\ | + | |
| - | (Energy-relevant improvement of building substance) “Final Report of the “Hamburg: Little Freedom 46-52” Funded project ID 0329750S. funded by PTJ. Steg Hamburg mbH, 2008.\\ | + | |
| - | \\ | + | |
| - | **[Feist 1995]** Feist, Wolfgang: Die Luftdichtheit im Passivhaus; | + | |
| - | (Airtightness in the Passive House) Passive House Report No. 6, Institute for Housing and Environment, | + | |
| - | \\ | + | |
| - | **[Feist 1997]** Feist, Wolfgang: Das Niedrigenergiehaus, | + | |
| - | (The low-energy house, a new standard for energy-conscious construction) C.F. Müller Verlag, 4th edition, Heidelberg, 1997.\\ | + | |
| - | \\ | + | |
| - | **[Feist 2003]** Feist, W.: Wärmebrücken und Verbesserung der Luftdichtheit im Altbau. In: Einsatz von Passivhaustechnologien bei der Altbau-Modernisierung\\ | + | |
| - | (Thermal bridges and improvement of the airtightness in oild buildings. In “The use of Passive House technologies for the modernisation of old buildings”); | + | |
| - | \\ | + | |
| - | **[Feist/ | + | |
| - | (3-D Airtight connections) Passive House Institute, Darmstadt, 2005. Not published.\\ | + | |
| - | \\ | + | |
| - | **[FliB 2002]** Fachverband Luftdichtheit im Bauwesen e.V.\\ | + | |
| - | (Specialists’ Association for airtightness in constructions) Supplementary Sheet for DIN EN 13829. Kassel, November 2002\\ | + | |
| - | \\ | + | |
| - | **[Kaufmann/ | + | |
| - | (Modernisation using Passive House components. | + | |
| - | Passive House Institute Darmstadt, February 2009.\\ | + | |
| - | \\ | + | |
| - | **[Peper/ | + | |
| - | (Airtight Planning of Passive Houses) CEPHEUS Project Information No. 7, Passive House Institute, Darmstadt 1999.\\ | + | |
| - | \\ | + | |
| - | **[Peper 2000]** Peper, S.: Luftdichtheit bei Passivhäusern - Erfahrungen aus über 200 realisierten Objekten\\ | + | |
| - | (Airtightness in Passive Houses – Experiences gained from over 200 realised buildings); Conference Proceedings of the 4th Passive House Conference, Passivhaus Dienstleistung GmbH, Kassel and Darmstadt, 2000.\\ | + | |
| - | \\ | + | |
| - | **[Peper 2005]** Peper; S.: Beratung zur Qualitätssicherung beim Projekt: „Hamburg, Kleine Freiheit 46-52, Energetische Verbesserung der Bausubstanz“.\\ | + | |
| - | (Quality assurance for the project “Hamburg, Little Freedom 46-52: Energy-oriented improvement of the building substance”) within the framework of the PTJ sponsoring programme EnSan.\\ | + | |
| - | \\ | + | |
| - | **[Peper 2008]** Peper, S.: Luftdichtheit – unverzichtbar bei Passivhäusern.\\ | + | |
| - | (Airtightness – indispensable in Passive Houses) in: Passive House Component Catalogue, Ecologically evaluated constructions. IBO (Österreichisches Institut für Baubiologie und -ökologie) Publiher: Springer Vienna New York. Second extended edition Wien 2008. ISBN 978-3-211-29763-6\\ | + | |
| - | \\ | + | |
| - | **[Peper/ | + | |
| - | (“Existing Passive Houses”: building refurbishment in Ludwigshafen/ | + | |
| - | \\ | + | |
| - | **[Peper/ | + | |
| - | (On the durability of concepts for airtightness in Passive Houses, field measurements) Research Report within the framework of the IEA SHC TASK 28 / ECBCS ANNEX 38. Passive House Institute, Darmstadt, June, 2005.\\ | + | |
| - | \\ | + | |
| - | **[Schulze Darup et al 2005]** Schulze Darup, Burkhard (Herausgeber): | + | |
| - | (Jean-Paul-Platz 4 in Nuremberg – energy-relevant modernisation of buildings with a factor of 10. Final Report of the scientific monitoring), | + | |
| - | \\ | + | |
| - | **[Zeller et al 1995]** Zeller,J.; Dorschky, S.; Borsch-Laaks, | + | |
| - | (Airtightness in buildings – measurement of airtightness by means of the blower door in low-energy houses and other buildings), Institut für Wohnen und Umwelt, Darmstadt, 1995. | + | |
planning/refurbishment_with_passive_house_components/thermal_envelope/airtightness.1547116748.txt.gz · Last modified: 2019/01/10 11:39 by cblagojevic