WORTH KNOWING
Prevention Of Mould And Mildew In Skylights
Three factors affect the growth of mould and mildew:
• Presence of organic matter
• Temperature
• Air humidity
If the indoor temperature is higher than 5 °C and the relative air humidity is higher than 70-80%, mould and mildew will usually grow. Rising temperatures and air humidity will only increase their growth. For such conditions, the inside of the upstands should be made of a non-organic material.
• Presence of organic matter
• Temperature
• Air humidity
If the indoor temperature is higher than 5 °C and the relative air humidity is higher than 70-80%, mould and mildew will usually grow. Rising temperatures and air humidity will only increase their growth. For such conditions, the inside of the upstands should be made of a non-organic material.
Princip for ventileret karm
Wooden upstands need to be ventilated
In order to avoid mould and mildew on upstands it is important that unintentional moisture in the upstand construction can evaporate and escape to the building exterior. For this to happen, proper ventilation is essential.
Our solution
In co-operation with DTU (Technical University of Denmark) Primalux developed an insulated wooden upstand with a vapour barrier and ventilation which minimize the growth conditions for mould and mildew.
DTU has calculated that the upstand must be ventilated for half of its length, with a maximum of 80 mm between the air gaps.
The vapour barrier is necessary to prevent moisture from entering the construction from the inside. The barrier must not be a hygrodiode. Experiences with hygrodiodes in roof cassettes show that it is very important for all surfaces to get a certain amount of sunlight if the hygrodiode is to function properly. This is not possible for the part of a skylight upstand which faces north.
Furthermore we find that by painting upstands on the inside, moisture is prevented from entering the upstand.
Therefore, our solution is a diffusion tight vapour barrier and a ventilation of the upstand construction. These two measures prevent or evacuate the moisture that would otherwise cause mould and mildew to grow.
In order to avoid mould and mildew on upstands it is important that unintentional moisture in the upstand construction can evaporate and escape to the building exterior. For this to happen, proper ventilation is essential.
Our solution
In co-operation with DTU (Technical University of Denmark) Primalux developed an insulated wooden upstand with a vapour barrier and ventilation which minimize the growth conditions for mould and mildew.
DTU has calculated that the upstand must be ventilated for half of its length, with a maximum of 80 mm between the air gaps.
The vapour barrier is necessary to prevent moisture from entering the construction from the inside. The barrier must not be a hygrodiode. Experiences with hygrodiodes in roof cassettes show that it is very important for all surfaces to get a certain amount of sunlight if the hygrodiode is to function properly. This is not possible for the part of a skylight upstand which faces north.
Furthermore we find that by painting upstands on the inside, moisture is prevented from entering the upstand.
Therefore, our solution is a diffusion tight vapour barrier and a ventilation of the upstand construction. These two measures prevent or evacuate the moisture that would otherwise cause mould and mildew to grow.
