The simplicity of a warm flat roof makes it one of the most popular designs providing an effective and easy way of insulating a building.
Warm or cold flat roof construction.
When we talk about a warm roof vs a cold roof what we re really talking about is the insulation of the flat roof.
In the case of a flat roof insulation is usually either a rigid board above the deck or a mineral glass wool quilt immediately above the underdrawn ceiling depending on the type of roof design and construction.
Ventilation is required for these roofs.
The cold roof although not recommended today and actually banned in scotland until recently cold flat roofs were fairly common.
It is the most acceptable type of construction for domestic possessions and belongings as it avoids the need for aeration of the roof construction.
In case of warm roofs they have an insulation above the roof deck in this way it keeps the deck warm.
Warm roof designs will make the entire structure of the building warm in order to avoid cold bridging an element of the building that allows heat or energy loss.
On a flat roof this could be air in at.
Hot tar and gravel.
Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.
The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof.
The 3 most common materials used for flat roof construction.
Installing a warm roof can be extremely straight forward and simple to do.
Basically there are two options to choose from when insulating a flat roof.
There are several methods and materials for the design of the exterior surface of a warm or cold flat roof.
Others would treat even steeper pitches as flat roofs.
Flat roof constructions are generally classed as either cold or warm roofs depending on the position of the thermal insulation.
A cold flat roof insulation requires more work taking off old boards and replacing them and the roof surface.
Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold roof.
The recognised flat roof build ups for best design practices are.
Cold roof construction requires that a suitable ventilated air space exists above the insulation layer within which the air is constantly mobile being replenished by fresh incoming air whilst the air resident within the void space is being expelled via a natural vent action at another point.
The breakdown warm roof vs cold roof.
For that reason cold flat roof construction needs to keep in mind the need for unblocked airflow.
