What is Flat Roof installation

what is flat roof installation

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.

How to insulate flat roof in Newyork?

flat roof insulation in newyork

It is always advised to get a professional installation company to carry out the roof insulation and is considered vital to get a professional contractor for your insulation needs. Before that, it is important to understand the types of flat roofs and their insulation requirements. There are two types of flat roofs; Warm Flat Roof and Cold Flat Roof. The positioning of the insulation is what makes the real difference.

In certain regions cold flat roof constructions are not allowed due to the damage they cause overtime on the structure.

Warm Flat Roof: In warm flat roof constructions, the process starts by placing a minimum of 100mm of rigid board insulations on top of the weatherproof roof membrane. This protects the layers underneath from extreme weather conditions. The positioning of the board is the important part since it plays a significant role in the insulation performance. Once this layer is added, a top layer of asphalt is added to finish the job. After this the roof is ready to be utilized for different purposes as well like adding soil and growing a mini nursery. Warm roof is considered the best way to insulate the flat roof since it prevents condensations issues. Warm deck construction is the most acceptable insulation method in new building ventures.

Cold Flat Roof: In Cold flat roof constructions the insulation boards are placed below the timber joists leaving appropriate ventilation between the roof and the insulation, this leaves the deck cold. This method is usually used in old buildings or refurbishment projects. The insulation material is carefully placed leaving a gap of 50-60mm between the roof and the insulation material, enabling air flow through the structure. At times there is a possibility that the contractor might need to take down your ceilings. In case of shallow joists, spray foam is the best option to use to insulate the space and is likely to be advised by the contractor insulating your roof. Normally cold roof is not preferred because the spread of air is multidirectional and with reduced ventilation it can cause moisture build up leading to condensation. Achieving the right level of ventilation is very difficult to achieve and the added pressure on the head heights make this option the least recommended one. Cold roofs in cold weathers can make condensation a bigger issue causing decay of the building structure due to lack of ventilation.

How to select flat roofing insulation material?

flat roof repairing

As flat roof insulation is an important component of your property to help maintaining th temperature, it is essential to know the types of flat roof insulation and their R values. As all insulation have R value assigned to it the greater the value the more efficient the insulation will be.

Following are several types of flat roof insulation:

  • Wood Fiber: in many cases people look for organic alternative in order to insulate their flat roof, if this is the case then your best choice would be wood fiber. They are wood boards made up of mixture of fibers with various fillers and binding materials and is purely organic. Its surface might sometimes be coated with asphalt in order to enhance the water resistance. Wood fiber insulation has a R value measured at around 2.7 per inch. This type of flat roof insulation may be considered as the cheapest option however it is not suitable in many situations. Many roofers believe it is not a good choice if one is living in humid or rain prone area as the insulation material is at a greater risk of damage.
  • Perlite: also belong to the organic family as it is a glass made by pressed and refined volcanic ashes, these are then combined with organic fibers and binders to turn into boards. Insulation for the flat roof takes place in a very unique way as compared to other types of insulation through air bubbles as soon as the air bubbles are trapped inside the perlite. To further enhance the quality of perlite it is often painted with asphalt coating. This type of insulation is also considered to be one of the economical choices.
  • Polystyrene: this type of insulation exists in two forms which can be expanded and extruded. Expanded polystyrene flat roof insulation is produced through mixing the foaming agent with polystyrene. On the other hand, extruded polystyrene is formed by heating and expanding the polystyrene. It is believed that this type of insulation consists of excellent energy conserving qualities leading to a positive impact on the energy consumption for the owner of the property.
  • Glass cells: glass is crushed and heated while in the mold. It is available to bought in flat or tapered blocks to be used for insulation on flat roofs.  It is often regarded as a good choice.
  • Polyisocyanurate: this is placed between organic and non organic felt within the flat roof. This type of insulation is expanded by using foaming agent called pentane to expand the foam resulting in better standard of insulation. Polyisocyanurate has an R value of 6.0, thus is considered to be the best option while spending the money on insulation.