I am trying to simulate the behaviour of a sandstone wall with insulation on the inside. Due to heavy rain towards the western wall, the sandstone becomes more and more moist.
I want to hydrophobize the sandstone.
How can i simulate this in WUFI 5.0 Light?
Simulating sandstone wall after hydrophobizing
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Andreas Hauser
- WUFI User
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- Joined: Wed Oct 27, 2010 7:49 pm -1100
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Christian Bludau
- WUFI SupportTeam IBP
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- Location: IBP Holzkirchen, the home of WUFI
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Hello Mr. Hauser,
to simulate the hydrophobizing effect of a painting, plaster etc, you have to add a hydrophobing layer on the sandstone, thickness 1mm and change the a-value [kg/m2/sqrt(h)] of the layer.
Unfortunately Wufi Light doesn´t allow to create a new material or change the values.
To try out the effect, use a lime cement plaster (stucco) on the sandstone... it´s a-value is 1 [kg/m2/sqrt(h)].
Hpe that helps,
Christian Bludau
to simulate the hydrophobizing effect of a painting, plaster etc, you have to add a hydrophobing layer on the sandstone, thickness 1mm and change the a-value [kg/m2/sqrt(h)] of the layer.
Unfortunately Wufi Light doesn´t allow to create a new material or change the values.
To try out the effect, use a lime cement plaster (stucco) on the sandstone... it´s a-value is 1 [kg/m2/sqrt(h)].
Hpe that helps,
Christian Bludau
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Joseph Little
- WUFI International Support Team
- Posts: 13
- Joined: Wed Dec 15, 2010 6:25 am -1100
- Location: Dublin, Ireland
- Contact:
a-values
Hi Christian,
Where do you change the a-value (in WUFI 5) and what are a sensible range of values for it?
I feel the Online Help could definitely have more about this.
Many thanks.
Regards, Joseph
Where do you change the a-value (in WUFI 5) and what are a sensible range of values for it?
I feel the Online Help could definitely have more about this.
Many thanks.
Regards, Joseph
-
Christian Bludau
- WUFI SupportTeam IBP
- Posts: 1160
- Joined: Tue Jul 04, 2006 10:08 pm -1100
- Location: IBP Holzkirchen, the home of WUFI
- Contact:
Hello Joseph,
you can change the a-value the following way. Cut of a layer of you external material (eg. 1 cm, the thickness the hydrophobic liquid may suck into the material. Then you edit the material data. Unlock the material, than choose for both of the liquid transport coefficients “generate”. A new input-field will appear on the left side, allowing you to enter the water absorption coefficient. Please be carefull with the units, it is in kg/m²s^1/2.
We have a German guideline from the WTA*), which postulates that the a-value for hydrophobizing layers on surfaces have to be lower than 0.1 kg/m²h^1/2.
Best regards,
Christian
*)
Hydrophobierende Imprägnierung von mineralischen Baustoffen
Referat 3 Naturstein
WTA Merkblatt 3-17. Stand Juni 2010
Hrsg.: Wissenschaftlich-Technische Arbeitsgemeinschaft für Bauwerkserhaltung und Denkmalpflege e.V. -WTA-, Referat 3 Naturstein, München;
2010, 18 S., 4 Abb., 2 Tab., Geheftet
Fraunhofer IRB Verlag
ISBN 978-3-8167-8312-1
you can change the a-value the following way. Cut of a layer of you external material (eg. 1 cm, the thickness the hydrophobic liquid may suck into the material. Then you edit the material data. Unlock the material, than choose for both of the liquid transport coefficients “generate”. A new input-field will appear on the left side, allowing you to enter the water absorption coefficient. Please be carefull with the units, it is in kg/m²s^1/2.
We have a German guideline from the WTA*), which postulates that the a-value for hydrophobizing layers on surfaces have to be lower than 0.1 kg/m²h^1/2.
Best regards,
Christian
*)
Hydrophobierende Imprägnierung von mineralischen Baustoffen
Referat 3 Naturstein
WTA Merkblatt 3-17. Stand Juni 2010
Hrsg.: Wissenschaftlich-Technische Arbeitsgemeinschaft für Bauwerkserhaltung und Denkmalpflege e.V. -WTA-, Referat 3 Naturstein, München;
2010, 18 S., 4 Abb., 2 Tab., Geheftet
Fraunhofer IRB Verlag
ISBN 978-3-8167-8312-1