Manufactured Roof Trusses Designed for Extra Energy Efficiency
Raised heel trusses sit higher above the top wall plates to make extra room for attic insulation
In the early stages of planning for the Model Remodel, Ben was hoping to salvage the roof because the client had just put on new metal about five years ago and they were hoping to not have to replace a roof that they spent a little extra cash on so it would last a lifetime.
But a finished single-story gable house doesn’t photograph very well when there are two ridge heights, one of which is a swayback. The house had been added to four times since 1930, and the roof line showed it.
Ben says some of the remodeling was done “with better intention than knowledge,” which is a diplomatic way to describe what other remodelers may be tempted to call a ‘clusterf*ck.’
Editor’s note: ‘With better intention than knowledge’ is a phrase worth tucking away in the ol’ bag of customer-language tricks; it could be a good way to describe what they are asking you to put lipstick on.
Fortunately, Valspar and Huber came in as sponsors, so new metal roofing and roof sheathing were covered. This made removing the old roof a lot easier to embrace budget-wise.
That left the roof framing, which in this case, is manufactured trusses—which are a fast way to get the roof ready for sheathing. Rather than choose a standard truss, Ben specified what’s called a ‘Raised-Heel’ truss, which are also known as high heel trusses.
They are not called high heel trusses because you have to wear high heels to install them. That is optional.
They are called raised heel, or high heel trusses because the heel height above the top plate is raised up high to make more room for insulation.
Standard trusses have a heel height of about 4-½ inches above the top plate.
If you subtract an inch for ventilation space, that means 3-1/2 inches of insulation is mashed into that itty bitty corner.
Thin insulation at the roof/wall intersection can cause ice dams if you live in a snowy place. If you live in a hot place, it just makes your AC unit work harder than it should have to.
Raised heel trusses can take a couple of forms. Sometimes the truss manufacturer wedges a scrap of 2x6 between the bottom chord and the top chord, which can give better clearance for insulation.
The trusses engineered for the Model Remodel have a short length of vertical 2x4 to raise the top chord 14 inches above the top plate.
This translates to about 13 inches of space for insulation at the outside edge of the roof/wall connection after space for roof venting is deducted.
Raised heel trusses are an easy way to dramatically improve the energy efficiency of the homes you build and remodel without adding any labor or materials charges.
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