How To Vent A Warm Flat Roof

Firstly there are two types of flat roof.

How to vent a warm flat roof.

In the summer differences between your roof temperature and the outside air can still cause condensation especially interstitial condensation or water trapped in the layers of your roof. In the warm flat roof construction there is insulation packed into every possible space where air can flow. The roof itself is therefore kept warm. The major difference between the warm flat roof and the cold flat roof has to do with the air flow between the roofing timbers known as joists that help to hold up the roof.

I am skeptical that soffit vents on each end of a rafter spacing. He has come across just about every type of flat roof in existence. But unlike a more steeply pitched roof there is no low soffit vent and higher ridge vent to set up a convective ventilation current. That s not to say that roof ventilation is only valuable in the winter.

In general the roof structure is better protected from the more extreme scales of hot and cold weather. Unvented flat roofs a technical discussion flat roofs have often been built with the insulation all on top of the vapor closed drainage plane as this avoids dew point condensation issues inboard of the roofing. Vents ensure that a roof will be the same temperature as the air outside of it. They work with multi layer and three layer roofing systems helping to reduce the build up of moisture.

A warm roof and a cold roof. In general it is suited to external outbuildings. A warm roof is defined as being when the all or the majority of the insulation is above the joists or deck. The lower cost of installing a cold roof is usually one of its main advantages.

From asphalt to zinc. This video shows the key features of a flat roof cold deck construction and how to draw the details to a scale of 1 10. Klober breather vents can be installed in both cold and warm flat roofs if needed and their design enables them to ventilate between the layers. Roof is flat fibreglass so no over fascia vents like you would do with pitched roof.

I only know that during the last building regulation inspection. Steven has been working on london s flat roofs for over 30 years. On flat roofs with an overhang it is possible to install continuous soffit vents tied into a continuous ventilation baffle between the rafters. However in many situations the insulation may need to be primarily or entirely below the flat roof membrane and between the roof joists if so what are the best options.

If you have any questions or need any advice feel free to drop a comment below and he will endeavour to reply. The fascia wood is screwed directly onto the end of the roof joists and there are no soffits to put a vent into.