Posted by roofcoadmin November 5, 2018
As high as 90 percent of roofs upon commercial structures comprise of low slope designs that have rigid insulation connected with decks of concrete or steel. Within those systems, insulation may play 3 roles:
- Working platform
- Thermal barrier
Maximizing every role of the insulation will increase the ROI of your roof.
Breakdown of Thermal Functionality
Heat will travel through roofing in 3 ways. Each will have a different effect upon building performance, as well as options that are obtainable to control it.
- Conduction will happen inside solid materials, as well as between solid materials within physical contact. It’s the most intuitive heat transfer path.
- Convection happens inside liquids and gases as a result of heat conduction inside the liquid or gas and movement of those substances. For roof insulation, it’ll mean air gaps, latent or entrapped moisture and negative pressure/wind uplift.
- Radiation will happen independently of liquids, gases, and solids, like when the sun heats roofing or heat will radiate outward from the structure in the evening.
For conduction, the roof insulation’s unit R-value and overall unit R-value of the full roof assembly ought to be increased. In order to raise R-value, the quantity and selection of roof insulation are key factors. More insulation will mean more unit R-value. But various materials provide various unit R-values.
“R-Value” displays the unit R-value of a variety of insulation types. XPS and Polyiso provide the greatest thermal values per inch.
In order to raise the overall unit R-value of the assembly, give consideration to every element’s unit R-value, as the value for each one is going to be different. The values for every component within an assembly are additive.
All thermal “shorts” or bridging across elements are going to have to be controlled because they are set to reduce the assembly’s overall value. A mechanical fastener is a constant bridging cause. Choices to control these types of shorts involve fastening every layer in adhesives and utilizing non-thermal bridging fasteners. A monolithic roof insulation, which includes a lightweight concrete and spray foam, also can be utilized to get rid of shorts.
Control Convection Strategies
Owners have 2 strategies to get rid of the convection waste upon their roofs:
- Control moisture condensation and movement
- Control air movement
Ensure Insulation is Adequate Working Platform
Your roof and its insulation, over its lifetime, is going to serve as a working platform for a number of trades during maintenance and construction. The roofing insulation might require temporary protection before your roof system is finished, as well as permanent protection after system completion.
Utilizing cover boards over roof insulation is a good practice. Additional choices involve selecting a roof insulation that has suitable compressive strength, as well as installing walkways. Observing roof traffic and access – what trade is on the roof, as well as when – also is critical.
Roof insulation only is a single component of the roof system; however, it performs several functions which you may optimize for your structure.
For more information on our Winnipeg roofing company contact Roofco today!