How To Vent A Warm Flat Roof

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.

How to vent a warm flat roof. It will also prevent warm air from drifting into the roof void. The fascia wood is screwed directly onto the end of the roof joists and there are no soffits to put a vent into. I need to vent the 50mm gap above the ceiling insulation on a cold deck flat roof. 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.

Roof is flat fibreglass so no over fascia vents like you would do with pitched roof. In general the roof structure is better protected from the more extreme scales of hot and cold weather. That s not to say that roof ventilation is only valuable in the winter. 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.

He has come across just about every type of flat roof in existence. I am skeptical that soffit vents on each end of a rafter spacing. From asphalt to zinc. If you have any questions or need any advice feel free to drop a comment below and he will endeavour to reply.

By majority the rule of thumb is that in a domestic house not flats approximately a third of. Steven has been working on london s flat roofs for over 30 years. 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. The roof itself is therefore kept warm.

Firstly there are two types of flat roof. A warm roof is defined as being when the all or the majority of the insulation is above the joists or deck. I only know that during the last building regulation inspection. In the warm flat roof construction there is insulation packed into every possible space where air can flow.

They work with multi layer and three layer roofing systems helping to reduce the build up of moisture. On flat roofs with an overhang it is possible to install continuous soffit vents tied into a continuous ventilation baffle between the rafters. 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. Vents ensure that a roof will be the same temperature as the air outside of it.

A warm roof and a cold roof. In general it is suited to external outbuildings.