Venting A Cold Flat Roof With Parapet Walls

When thermal insulation is placed below the deck the ventilation must.

Venting a cold flat roof with parapet walls.

Used to provide ventilation where flat roofs abut masonry. What is flat roof ventilation. Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings. Cold roofs by the way are not recommended for high humidity areas see the blog on how to insulate.

I have a cold flat roof ventilated by soffit vents on one side and no ventilation on the other side. The 25mm batten space creates a clear airpath to the roof void below so reducing the possibility of condensation and mould growth. There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation. The rav fl promotes air entry where a flat roof abuts a vertical masonry wall.

On the unventilated side there is no overhang just a solid facia board flush with the wall. The disadvantage of this method is wasteful cutting of insulation to install between the joists labour required to install the material and increased electrical cables required to prevent overheating that run within the insulation. It is supplied with pre drilled fixing holes and an integral insect resistant grille. Where there is a parapet or an external wall abutment to the flat roof the fv250 ventilator can be used above a 150mm timber upstand battened off the wall by 25mm as shown below.

In this way the roof itself is kept cold. Each unit is 1 2 metres in length and the heavy duty profile incorporates an integral pivothold hinge. How do i add ventilation on this side to create through air movement. A cold roof system sees the insulation placed immediately above the ceiling between the joists with ventilation space above the insulation.

You only need ventilation in a cold roof. Venting of flat roofs. Vparawallcr ventilated parapet detail cold roof installation of a typical ventilated parapet detail with the dryseal flat roofing system on a cold roof construction. No insulation is on top.

Venting in building construction as a technique of cooling by air flow and of controlling or removing moisture has been in use for many years.