This is the least expensive form of insulation for the attic floor.
Raised heel attic truss.
The raised heel truss below shows how a vertical member is added to the roof truss to raise the top cord at the eave.
With raised heel trusses it may be possible to put hvac ductwork in the attic without the system losing too much heat.
Builders don t need special tools or know how to build with them.
The guide can be downloaded for free from the apa s website.
It greatly simplifies attic ventilation and it leaves ample room for insulation above exterior wall top plates.
Building is designed in accordance with the irc.
Raised heel trusses 9 1 4 to 15 1 4 inches in depth.
Combined with a properly designed attic ventilation system and some well placed air sealing a roof framed with raised heel aka high heel or energy trusses reduces the temperature and pressure differences between the conditioned living space below and the unconditioned attic area thereby reducing thermal transfer or heat loss between those spaces.
Truss heel height the vertical depth of the truss at the outside face of the bearing.
This allows us to install full depth insulation across the entire ceiling attic.
Ventilation eave baffles if needed for air flow.
More importantly the raised heel provides the opportunity to increase energy efficiency to meet new energy code requirements.
Which in turn improves the overall energy efficiency of the home.
The raised heel provides additional space for cheaper attic insulation and for the full depth of insulation to be extended right to the outside of the top plate.
Standard heel typical truss heel height is about 4.
Raised energy heel typical truss heel height is about 12 but may be designed to most any height per the building designer specification.
Easy to build with.
A raised heel truss is identical to a conventional truss except for one difference.
With a raised heel truss you have enough space to utilize cheaper insulation methods such as blown cellulose or fiberglass batts.
Raised heel trusses are installed the same as conventional trusses.
When insulation is compressed its r value is reduced.
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.
Also the raised heel trusses are assumed to have a heel height of between 9 inches to 15 inches.
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.