Building Regulations

In April 2006 the Government of England and Wales implemented changes to Building Regulations Approved Document L (Conservation of fuel and power). These revisions have a significant affect on homeowners and domestic roofing contractors. 

The regulations were changed to implement the EU Energy Performance of Buildings Directive (EPBD), which aims to reduce energy use in domestic buildings by 20% compared to the 2002 regulations. 

There are essentially two designs used in the construction of a flat roof to include insulation. 

Cold deck (fig 1) 

This is the most common construction and can be the least thermally efficient. This roof design can also be prone to the manifestation of condensation within the roof void. From the room ceiling up the build is as follows: the ceiling is attached to the roof joists that support the roof construction. A polyethylene vapour barrier is laid into the roof void and mineral insulation is loose laid between the rafters. The roof deck is then fixed to the rafters and the water proof membrane is then installed. In some cases this construction may have to be ventilated to avoid condensation.

Warm deck (fig 2) 

This is the most modern method of construction and should be used were possible (although not all situations are able to accommodate this design). 

From the room ceiling up the construction is as follows: The roof joists support the roof construction the internal ceiling is attached to these. On top of the joists the roof deck is fixed. A vapour barrier is laid on to the deck and the appropriate thickness of insulation is fixed to the roof deck. The waterproof roof cover is then installed. 

This method of insulating the roof alleviates the formation of condensation in the roof void, and complies with the current building regulation.

OPTIM-R Roofing System 

Roof Technology are experienced installers of the next generation of insulation products for flat roofing 

Kingspan OPTIM-R is a rigid vacuum insulation panel, encased and sealed in a thin, gas-tight envelope, giving outstanding thermal conductivity and the thinnest possible solution for flat roofing insulation. Ideal for situations where low u values are required, & design constraints mean that insulation depth is an issue. 

Kingspan OPTIM-R Roofing System provides an insulating performance that is up to five times better than other insulation materials. 

OPTIM-R installation is specifically designed for each installation. 

The vacuum insulated panels are installed with rigid thermoset (PIR) insulation infill panels which can be cut to fit around problem areas such as roof lights or ventilator kerbs. 

The Kingspan OPTIM-R Roofing System is designed for use where there is a requirement for low U-values and the thinnest possible roof build-up. It is particularly suited for applications where there may be little space for installing new roof insulation, for example in buildings with planning height restrictions, terraces, balconies & flat roofs with low window thresholds. 

Roof Technology are able to provide design & costs for any application where these high preforming products might be of benefit.

Read more 

• What does this mean for homeowners? 
• Can I avoid the extra expense? 
• What happens if you do not comply with the new regulations? 
• Building Regulations Approved Document Part L Exceptions