Flat Roof Insulation Requirements

A note to consider before construction.

Flat roof insulation requirements.

U value of a flat roof to comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Continuous insulation zones ashrae 90 1 ashrae 189 1 igcc ibc iecc 2004 2007 2010 2013 2016 2009 2011 2014 2012 2015 2009 2012 2015 0 25 1 15 20 2 15 20 25 3 15 20 25 4 15 20 302535 5 15 20 302535 6 15 20 3035 7 15 20 3540 25 8 20 3540 25 minimum r value non residential above roof deck. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

If the old roof has hvac equipment gas lines fans skylights soil stacks antennas or other equipment on the rooftop. If insulation is installed below the flat roof deck this is called a cold roof. Consider geography budget and use for the roof to determine the best option. Insulation can also help to limit condensation and contribute to acoustic insulation depending on the type of insulation used.

In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay. Insulation material is placed on top of the roof rather than in between the ceiling and the decking. Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling. From there the flat roof system you choose will determine the materials you apply.

Insulation is placed in between the joists underneath the roof surface above. There are many different types and installation methods out there along with a lot misinformation about which products offer the greatest energy savings. Both these variants require different approaches to insulation which will be covered in this guide. Cold roofs and warm roofs.

Our guides to building regulations in wales adl1a 2014 building regulations. There are two types of flat roof. Here we share the most common mistakes people make when installing flat roofing insulation. Wales new dwellings.