Small Straw Bale Cabin. Advice?

Im building my first timber frame this summer here in western Massachusetts. Its basically the garden tool shed from Timber Frame Construction by Sobon and Shroeder with a few slight adjustments. A big change I'm doing (which wont affect the frame itself too much) is that I'll be insulating (ie, wrapping) the frame with straw bales to make a genuine non-load-bearing straw bale house. Cool, right?

My question for the day is this: We want a porch on the long wall. What are my best options - timber framed or stick framed - for connecting the porch to that end wall?

Also, as the exterior footprint is larger than the interior by a number of feet because of the bales, the floor system needs to be modified/expanded. Does a deck (stick framed) make the most sense and forgo the sills and just lay the posts on the deck? Or would some sort of funky cantilevered system work better? I guess its important to say the foundation will be 10" piers.

Finally, any thoughts on roof insulation? Not only is insulation something to think about, but strawbales require 3-4' overhangs on all sides, including the gable ends, so I'll need some roof system that can go on top of the rafters and give me my overhang. I know the ISP and TGI joists are options, but I would prefer salvaged materials rather than buying new. Any ideas?

OK - I hope this doesnt offend anybody (sometimes you odnt know with forums). In the hope, but not expectation, that someone out there does have an answer or two for my questions I'm going to keep posting them.

My 3 big questions still remain. In regards to the deck. How can I frame it so its strong enough, and also in relation to the pier foundation. Should the piers be at the corners and edges of the deck, or can I cantilever the deck past the piers so that the piers can be directly below the posts? Also, we want to extend the deck on the east side (gable end) to make a small "walkway" (no extra roof, not screened in, somewhere to sit in nice weather, etc.) How can this be built and supported, plus then there would be no space between the wooden "walkway" and the bottom of the bales. Is this OK?

So many questions, and the answers will come to me somehow. I know it!

Cantilever the joist out past the frame across a sill sitting on the piers. They should be sized to the load and length of the cantilever. The post mortice into the sill on the piers. Drop the walking deck below this level to allow water and snow to not effect the wall system. I would say it is not OK to keep it at the same level.

Why no extra roof? Don't forget your gutters. Might as well collect it for the gray water system.

Tim

Do you have a "rebuild it" or "restore" type salvage materials operation in your area? There are lots around here (NW). They always have leftover bits of insulation from other jobs that would be good for a small project such as yours. If you go new, consider denim insulation. Great product. New, but "salvaged" from land fills.

How are you going to support the roof that is over the bales, and the overhang?

HI Dan. Sorry I didn't see this posting until now, but here goes. I don't know if you've already built your structure or not...in any case, a straw bale building doesn't require a 3'-4' overhang; most buildings that we build have between 24" and 36", depending on the design. A small shed such as you are (did?) planning on building could get away with a much smaller overhang. The plastered bale walls can be further protected by a silicate dispersion paint manufactured by a small Canadian Company, Eco-House. This paint, while still being permeable (critical to a bale wall) repels water- like gore-tex for bales!

Hey Tina,
No structure yet. Thanks for that great advice. I think I will still keep a fairly significant overhang (3’4’) on the long ends, and maybe I’ll bring it down to 24”-30” for the gable ends. If I use SIPS for the roof insulation, the doublechip panels can cantilever that amount.

What do you think about Tim’s recommendation above? For the deck, I could keep this “walkway” at the same height as the rest of the building, or I could maybe drop it a few inches below for the sake of the bales. I would like to keep the house as close to the ground as the bales and plaster walls will allow (18”?), as with using piers I don’t want a house that appears to be floating.