Engineered truss vs framed rafters

Started by dougpete, February 10, 2010, 09:58:15 AM

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dougpete

Greetings -

We are planning extending the Universal house out to 24 x 34 with two stories and attic over a full basement.  I have gotten some nice engineered truss documents from the local truss mfg and was planning on using them.  However, in thinking through the big picture it seems that framing the roof would be way easier to insulate using the method in the plans. 

The best way I can see to get a good seal with the trusses would be closed cell spray foam.

So, stick framing with rafters, while being harder, would probably work out to much less expensive, even if I hired some outside help to get the rafters up right.

Any thoughts?

Doug

John Raabe

Trusses are easy to layout and if you want, the truss company can build raised heel energy trusses that allow full depth blown in insulation all the way to the outside edge of the walls. Then, if you do an air sealed drywall ceiling (gaskets at the framing, hatch, and any lights and wiring penetrations sealed), you would have a high efficiency lid.

Spray foam is great too and does the airsealing with a high-R value insulation. You could do this with standard framing in the attic and then include this space in the house volume if you wanted. It would cost more of course.
None of us are as smart as all of us.


dougpete

Thanks John -

I think I will go with rafters, as they are quite a bit less expensive than trusses.  I would then have the option to use spray foam.  With five children, my family is probably on the larger size for the universal, so we need all the space we can get!

Doug ;)

John Raabe

Sounds like a plan!

Put good egress windows (and possibly a throw out ladder) in the gable end of the attic space if you will use it for sleeping.
None of us are as smart as all of us.