The roofs have the fundamental function of protecting the house from external elements, guaranteeing high performances of water impermeability, wind resistance and thermal insulation in order to obtain the minimum energy dispersion.
For this reason it is particularly important to provide the roof that is capable of all these qualities. We are going to explain Ventilated Roofing as explained by Macomb County roofers.
Roofs: technologies compared:
Each roof has a certain number of elements depending on the different type of functioning of the roof. These functional layers can generally lead to four types of roofing:
- non-insulated non-ventilated roof
- non-ventilated non-insulated roof
- insulated non-ventilated roof (warm roof),
- Ventilated insulated roof (cold roof).
An uninsulated and unventilated roof is a type of roof where neither heat-insulating elements nor a ventilation layer is added. Given the lack of insulation, it is used in limited cases where no thermal insulation of the system is required (such as roofing of agricultural buildings).
A ventilated uninsulated roof is the same as the previous one but with a ventilation layer underneath the sealing element, with the aim of improving the behavior of the roof in the summer as the ventilation reduces the effects of the heating due to the solar radiation. This solution is also generally adopted in agricultural construction.
The warm roof (that is an insulated but not ventilated roof) is constructed by heat-insulating layer but does not have a ventilation layer. A roof of this kind is therefore made up of the following layers: supporting element or roofing support (concrete cast in situ or mixed brick, precast concrete panels, wood panels, metal sheets, etc.), vapor barrier, thermal insulation, waterproof coat, ancillary works.
The cold roof (that is, an insulated and ventilated roof) has a composition similar to that of the warm roof but a ventilation space is inserted, which separates the layers of roof.
In the warm roof almost always the waterproof roofing is applied directly on the thermal insulation, which is its support, while in the cold roof the waterproof roofing is laid over the over-roofing which is almost always made of wood.
Generally hot roof is more widespread, especially in industrial buildings, while the cold roof, or ventilated roof, is mainly constructed in the case of wooden roofs, pitched roofs and residential buildings.
Ventilated roof: stratigraphy:
From a technological point of view, the ventilated roof must provide, from the inside to the outside:
– vapor tightness layer, when it is decided to insert it;
– thermal insulation element;
– ventilation layer (obtained by creating a gap with a constant thickness between the roofing elements and the underlying layer);
– roofing mantle, with foreseen ventilation openings at the ridge and the eaves.
Cold roof: how it works:
In the cold roof the ventilation layer greatly improves the thermal insulation of the roof; thanks to the ventilation the water vapor produced in the house are expelled outside the roof, thus preventing condensation.