Scissor Roof Truss With Energy Heels

Energy trusses have raised.

Scissor roof truss with energy heels.

The heel of a conventional plated roof truss where the bottom chord intersects with and bears on the perimeter wall plate and is fitted with a vertical member that literally raises the top chord of the truss. 347 framing and bracing a truss roof system. The extra height of a raised heel truss roof provides additional space for uncompressed attic insulation and the full depth of insulation to be extended right to the outside of the top plate. Most standard residential trusses can achieve r values r value referring to a rating that represents the insulation s capacity to resist heat transference from heated to non heated areas and vice versa of 11 or 13 near the sidewall.

Even in earlier versions of the irc code min for zone 4c was r38. The option 1 figure to the right shows a raised energy heel. Aka high heel or energy trusses reduces the temperature and pressure. A raised heel truss is much like it sounds.

This is created by designing the truss with a heel height tall enough to meet the r value requirements. The cost of additional insulation is very little and depending on your climate zone and the local energy code you may require less insulation if your. Termed an energy truss or advanced framing this can be achieved by using an oversized truss or raised heel truss as shown in commentary figure n1102 2 1 2. With this type of energy heel the wall sheathing will usually need to extend up the outside of the truss.

356 framing a skylight well with trusses. 353 framing with scissor trusses. To create a truss with an energy heel a vertical member is added over the supporting wall and the bottom chord stops there rather than extending into the overhang. Because raised heel trusses are high enough to leave the insulation value intact the energy code allows for use of less insulation for the entire ceiling system when raised heel trusses are used.

Energy trusses are designed to allow greater insulation depths at the heel. Raised heel trusses do not compress the attic insulation over the top plate which compromises the insulation value. The costs of insulating at the roof deck compared to at the truss chords is in most cases a much bigger up charge than the cost adder for energy heel trusses. In this situation the eave soffit is now higher up on the outside of the.

The solution for roofs framed with trusses is something called the raised heel truss also called an energy heel truss or energy truss.