Raised Heel Attic Truss Design

Use of wood structural panels for energy heel trusses.

Raised heel attic truss design.

Though extra material is used to create the trusses raised design the extra cost can be offset by the need for less insulation without compromising energy efficiency. According to the 2012 international residential code for seismic zones or zones designated for winds of 100 mph raised heel trusses more than 15 25 have to be blocked and braced. If prompted that the layer framing roof trusses is not displayed click yes to turn on the display of this layer in the current view. Raising the truss higher has two big advantages.

To build the energy heel truss click build framing roof truss from the menu. It is raised higher with a heel that extends up from the top of the wall and elevates the truss at the building s edges. Design a raised heel. While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses.

Also the raised heel trusses are assumed to have a heel height of between 9 inches to 15 inches. The cost of additional insulation is very little and depending on your climate zone. With this type of energy heel the wall sheathing will usually need to extend up the outside of the truss. This is created by designing the truss with a heel height tall enough to meet the r value requirements.

Using the select objects tool select the roof truss and then use the open object edit button. Raised heel trusses for efficient cost effective comfortable homes form r330 provides guidance on building with raised heel trusses for designs that meet these categories. It greatly simplifies attic ventilation and it leaves ample room for insulation. The guide can be downloaded for free from the apa s website.

On the general panel of the roof truss. Just as there are many types of roofs with many roof parts there are many different types of roof trusses this extensive article explains through a series of custom truss diagrams the different truss configurations you can use for various roofs. A raised heel roof truss design can improve the efficacy of the. Raised heel truss truss heel height the vertical depth of the truss at the outside face of the bearing.

Standard truss figure 2. Click and drag to draw a roof truss. A raised heel truss is identical to a conventional truss except for one difference. Raised energy heel typical truss heel height is about 12 but may be designed to most any height per the building designer specification.

We installed raised heel trusses with bottom chord overhangs on our house. Basic wind speeds of 110 mph or less ultimate design wind speed vult of 140 mph or less. Standard heel typical truss heel height is about 4. Raised heel trusses 9 1 4 to 15 1 4 inches in depth for other wind or seismic categories or raised heel truss depths consult the irc ibc or apa system report sr 103.