Any roof that has a pitch of less than 10 degrees and is horizontal is known as a flat roof. There is no loft space that is associated with pitched roofs so there will no loft hatch in the ceiling. Therefore, to prevent heat from escaping or coming in your property, insulating materials are laid between the ceiling and the roof membrane.

There are a number of factors that needs to be taken into consideration:

• Ventilation: It is to ensure that no construction material is deteriorated and to maximize the performance of the insulation. This is dependent on the positioning of the insulation board as it is sometimes necessary to ensure a ventilation gap.
• Loading: it is very important for the insulation to be of appropriate strength in order to adhere to the anticipated load and follow the building regulations. The strongest kind of boards are called Rigid insulation boards and are designed specifically to bare to all types of loads.
• Condensation: there may be a possibility of your environment being cold most of the times therefore cold roofs are more prone to condensation and might not have adequate ventilation leading to distortions and erosion of the materials.

Hence it is essential to consider the above mentioned factors before choosing the roof insulation.

Furthermore, there are different approaches to installation depending on the two main types of flat roofs:

• Warm Flat Roof: insulation material is placed at rafter level in order to keep the deck warmer.
• Cold Flat Roof: insulation material is placed at ceiling level leaving the deck cold.

According to the building regulation, as a general rule most of the flat roofs require minimum of the 100mm insulation to ensure the right levels of insulation. With regards to cold deck, 50mm of ventilated cavity is required typically for the air to flow and prevent from moisture being build up.

Effective insulation does not only make things easier for the property owners but also has an impact on the environment. Therefore government building regulations highlight the right level of roof insulation to avoid high levels of fuel to keep the building warm. Since these high levels will in turn have deteriorating effects on our surroundings. For this purpose there have been building regulation standards of insulation known as R values.