Interstitial Condensation Warm Roof

Inside the roof wall or floor elements.

Interstitial condensation warm roof. Interstitial condensation is condensation which occurs between layers of the construction i e. Inside the roof wall or floor elements. Interstitial condensation can create structural dampening that occurs when moist air penetrates inside the hidden space within an enclosed wall roof or floor cavity structure. Condensation happens when warm air comes into contact with your cold timbers.

Condensation risk analysis cra. Interstitial condensation can penetrate the walls floors and ceilings of a structure. Interstitial condensation commonly occurs when moist air permeates through elements of the building fabric across which there is a temperature difference typically but not always when warm moist internal air moves towards the cooler outer parts of external walls or roofs driven by a pressure difference. Let us use roof timbers as an example.

The incorporation of adequate insulation and ventilation in the roof void of a cold roof construction or sufficient insulation and vapour control layer in a warm roof construction will prevent the formation of interstitial condensation in the normal range of environmental conditions experienced. When that moisture laden air reaches a layer inside the interstitial structure that is at dew point temperature it condenses into liquid water on that surface. Interstitial condensation is a form of structural damp that occurs when warm moist air penetrates inside a wall roof or floor structure. Interstitial condensation is a form of damp that occurs when warm moist air from inside a structure moves into a wall and reaches the dew point and condenses within the core of the wall to form water.

Interstitial condensation happens on the inside of a structural material whereas condensation happens on the outside. The position of the insulation means that the roof deck and most of its structure has no protection from low temperatures during the winter. Interstitial condensation is condensation which occurs between layers of the construction i e. Upon contact the warm air cools reaches its dew point and forms water droplets on the outside of the.

It is important to ensure an element is designed to avoid interstitial condensation or to create an adequate ventilation solution to remove any condensation that forms. The standard of roof ventilation varies widely but the current building regulations specify that 270mm mineral wool should be used to insulate your a roof space at a minimum. The moisture laden air can penetrate into hidden interstitial wall cavity through the exterior in a warm humid outdoor period and from inside the building during. Interstitial condensation can cause deterioration or even failure of the components of the assembly potentially shortening their useful lifespan.