Ideas needed for canvas roof support

I built this structure as a combination hunting stand and summer play house for my kids but I'm needing some ideas to improve the roof before snow season. Time has been the limiting factor so far since I'm still trying to get some things finished on our actual house, but hunting season is here (archery anyway) and it needed to be enclosed ASAP. We did not purchase any wood for this project, the legs are 50 year old black locust posts that we repurposed from the half of the old pole barn that we had to take down, the steps and floor framing is rough milled lumber (mostly cherry) also probably about 50 years old that was milled on the property and has been stored in the pole barn for decades, plywood subfloor & 5 - 4x4 posts came out of the house renovation, and the 6th post and the horizontal beams are small trees that we took down to finish up this project and clear a shooting lane. Since time was such a factor, I ended up using 4x4 brackets on the tops and bottoms of the posts.

The plan for the roof was to extend the roof line about a foot to a second horizontal so that we have a 1ft overhang on each side and it uses the full length of the canvas tarp roofing material so that it is easier to pull it really tight so we don't get sagging with rain and snow. I'm not sure how to attach that second horizontal beam, but I was thinking we could also run some ribs from the peak to the eaves to help support the canvas come snow season and also maybe use them to attach the horizontal, but I don't know if that would be a strong enough joint to handle the tension we'll be putting on it with the canvas tied tight (I'm not sure if that even makes sense) or how I would keep the peak smooth if I have ribs setting on it. I have a whole pile of 1x2s or 2x2s that I could use as ribs (saved from the house renovation). Thoughts?

And I'd also welcome any ideas for the window/top half of the walls. We just strung some canvas drop cloth up there for now and he can pull it back like a curtain to see out, but it blows really bad in the wind so we definitely need something better. We'd like to do what we can with materials on-site, and something that won't take a ton of time because I'm still trying to finish the house.

*Also, I'm guessing that the bark on the locust posts wasn't an issue in the barn for 50 years because the posts were protected from moisture... now that they are outside in the elements, I'm guessing we should really try to de-bark them, is that correct? We also didn't have time to de-bark the posts we cut down, on all but 1 the bark was very thin... being up against the canvas roof, would it be wise to try to de-bark them at some point?

You could run your 1x2 or 2x2 ribs (rafters) flush with the top of the ridge pole instead of resting them atop it. You could use 1x2s attached to each side of the ridge pole as cleats to support your rafters and ensure they are properly placed so as to be flush with the top of the ridge pole.  

At the eave, maybe run 1x2 or 2x2 spacers between each rafter at the ends of the rafters, then attach a 1x2 running the length of the eave as your fascia.

Sam Benson wrote:You could run your 1x2 or 2x2 ribs (rafters) flush with the top of the ridge pole instead of resting them atop it. You could use 1x2s attached to each side of the ridge pole as cleats to support your rafters and ensure they are properly placed so as to be flush with the top of the ridge pole.  

At the eave, maybe run 1x2 or 2x2 spacers between each rafter at the ends of the rafters, then attach a 1x2 running the length of the eave as your fascia.

Thank you for the great ideas! It hadn't even occurred to me to run extra boards along the ridge pole but doing a cleat like that would completely solve my worry that attaching the ribs flush with the ridge pole wouldn't be strong enough. I'll update when we get the time to sturdy up the roof... probably won't be for a few weeks. And hopefully I'll have some ideas for better windows too.

Melissa said, "And I'd also welcome any ideas for the window/top half of the walls.

When we build our deer stand blinds we make a type of shutter above the window that is the same size as the window which is something like 1' x 3' of the same plywood.  We put hinges on it so it is easily raised with a block of wood like is used to hold a chicken house door open. Even a tree limb of the right size might work.

Your structure looks well made and is something that will last for years

My neighbor who has a mill and does a lot of wood working strongly believes that the bark should always be removed. Many insects bore into the type of plant cells that are in the layer beneath the "bark" and they will start the rotting process. Removing the bark removes their ability to hide there.

I've used many tarp roofs over the last 20 years.
1. The less they can "flap", the longer they'll last, so I would use more supports that are the equivalent of your red lines in your photo than you might think are strictly necessary.
2. I think I understand what the green line is for - to keep the bottom of the red lines in alignment under tension. However, I would add that to the underside of the red lines, so that if the snow bows the tarp between the red lines, you don't get a dam effect. A car shelter we have that has horizontal supports on the top side of the pipes, catches the snow in that location, stretching the tarp, and making the process worse. The shelter that I took 4" wide strapping and ran it down between the pipes in two spots taking a 7 ft span down to 2'4" span, even though it's a pretty wimpy fix, copes better with snow and allows us to clear off the snow much more easily.

Personally, I'm glad you used 4x4 brackets to hold this thing. All your time will be wasted if the first windstorm destroys it. Much of the reading I've done on simple building, stresses the use of "hurricane ties", although in my area they are more for earthquake safety. Yes, in a perfect world you use techniques with the lowest embodied energy as you can, but I've had a version of those brackets that allowed me to disassemble a small shed, then reuse all the parts rebuilding it in a different location that was more suitable for our long-term plans.