Post-Frame Shed Build

[deezler]

Wow, what a well structured approach (and thread!).

As an engineer myself I can really appreciate your thought process. But to build a scale model of a freakin pole shed!?!? hahaha! That's wayyyyy too much time (and $$) into just the planning stage. I am using google sketchup to design my own shed that I'll build this summer, for free.

Looking forward to the rest of the thread and results!

 

[MtnManSK]

Standing the Posts:

The next morning, we had to un-stack and re-stack the lumber to get to the treated posts which were on the bottom (intentionally, since the dirt won't hurt them).

We have (12) 6"X6" posts, (8) at 14' long, and (4) at 20' long. My wife and I could handle the 14 footers with moderate effort, but simply picking up and carrying the 20 footers was about all she could do (and worked me pretty hard as well). We're pretty small folks . . .

Around lunchtime, my wife hauled the Dingo back to the rental shop and went to a Dr.'s appt. in town while I stayed up at the cabin with our daughters (age 3 and 5) waiting for the footers to set-up a little longer.

When she got back that afternoon, we set to work standing the posts. After the difficulty we had moving the posts around, I knew we were going to need some mechanical advantage to raise them up vertical and slide them down into the holes. So, I set up a pretty ridiculous-looking rig with a 10-foot heavy-duty stepladder as a crane positioned over the hole. I tied the back-side of the ladder off to our ATV as a counter-weight, and we laid one of the 14' posts down perpendicular to the ladder on the opposite side. A 2X6 scrap served as a "slider" board at the back of the hole for the post butt to slide down as we raised it. Then, we connected a come-along winch from the top of the ladder to about 2/3 the way up the post.

Again, I wish I had gotten a picture of this, but we were so focused on what we were doing, that we forgot to pull out the camera.

This contraption actually worked pretty well for the first 14' post. Raising the post only took a few minutes, vs. the 10-15 min. it took to set up the rig. However, the next post we tried was a 20 footer. Those extra 6 feet made a HUGE difference, and we barely got it upright. The "crane" was a little too short, and we ended up having to muscle it up most of the way, which was not very safe or easy for one short man and his wife.

Here's where the story gets a little better. Apparently, two of our neighbors had been watching from the next house while we stood those first two posts. One is jack-of-all trades who isn't much bigger than me, but has done LOTS of construction work. The other is ex-military, and probably has nearly a foot and about 100 pounds on me. They claimed that they couldn't stand to watch us struggle any more, and between us three guys, we simply walked-up the rest of the posts in a matter of about 15 minutes.

This is what I love about these small mountain communities. Folks show up without being asked to help with the "heavy lifting" and don't ask for anything in return. We took them both a six-pack of their favorite beverage later anyway, but I can't tell you how much we appreciated their help just when we needed it most!!

 

[sfloggie]

Really enjoyable and interesting. Beautiful area..Thank you, Jim

 

[MtnManSK]

Plumbing and Setting Posts:

We decided to set the four corner posts in place first, and follow-up with the intermediate posts, installing some framing as we went so that we could remove and re-use braces.

We had a 58" carpenter's level that worked okay for plumbing the posts, but our neighbor with construction experience came to the rescue again with a much better tool. He had an extendable level that must have gone out to about 16' at its full extent. This allowed us to check the posts from top to bottom instead of just a few feet near the bottom, eliminating possible error due to slight curvature of the post.

He also let us borrow a set of "turnbuckle braces". These can be nailed to the end of a brace and staked to the ground so that the braces become infinetely adjustable in length. By installing two of these perpendicular to each other on a post, we could finely adjust them until the posts were virtually perfectly plumb. Again, we greatly benefited from someone else's generosity with tools and expertise. We can only hope to return the favor someday.

With plumbing them made so easy, it turned out that positioning them was the tough part. We knew where they needed to go based on our string lines, but once they were stood up, they DID NOT want to slide around on the concrete footings. We ended up having to wiggle and "walk" them close prior to bracing, and then use the back of a 6 lb maul to "bump" them the last little bit. We still weren't able to do better than about 1/4" precision.

Once they were positioned and braced, we dumped another bag of concrete (dry) in around their bases, and backfilled the rest with native soil, tamping VERY thoroughly as we went. This was long, hard hand labor, but we were able to get them set really tight.

This process took an entire day, plus another hour or so to get all 12 posts. As you can see, the weather was a little moist for part of that time, but we just "slogged" through it.

 

[MtnManSK]

Sidewall Framing:

The sidewall framing consisted of a treated 2X6 skirt board and 2X6 girts on 24" centers around the enclosed side of the shed. We also put a single run of 2X6s just under the eaves on the open side.

As you can see in the previous post, we did some of the framing concurrent to setting the posts so that we could move the braces and re-use them.

The first step was to set a "zero" elevation for the entire structure. This would ideally be done with a spinning laser level that could hit all of the posts at once. However, we didn't have access to one and didn't want to invest in one powerful enough to work outdoors just for this project.

So, we simply went to the post with the highest natural grade (back corner), and tacked on a treated skirt board about 1.5" above grade (sitting on a 2X6 block, to be exact). Then we set the long level mentioned above on it sideways, adjusted until it was level, and tacked it onto the next post. We continued this process of tacking, leveling, and nailing the skirt boards to all of the posts around the enclosed side of the shed. As a cross-check, we laid the level on the skirt boards across the middle of the enclosed side on the opposite end of our starting point. This verified that we had not drifted off of level on one side vs. the other.

Next, we measured up and marked for the height of the eave girts and nailed them on. For the open side, we had to again use the level to position them on the posts. Once we had one skirt board or girt on each post (and all were level), we had a reference point for all other framing.

For the intermediate girts, we cut two blocks at 18.5" each, and used them to space out each run without measuring every post. That went really fast.

Working our way up from the bottom, we could climb the framing while carrying the boards up and nail them in place. We didn't even need ladders.

 

[MtnManSK]

Rafters:

Most Post-Frame buildings these days utilize pre-fab trusses for the roof support (I have a shop at home that was built that way). However, with a run of posts down the middle of this shed, I didn't think it was necessary to use trusses, especially when I was pretty sure we would need a crane or other high-lift device to set them.

Since our span is only 12' on each side, I used deck beam tables and determined that double 2X12s could provide a load rating of 50 lbs/ft2. With a steel roof on a 6:12 pitch, I'm quite certain that the snow will slide off LONG before it gets that heavy. 50 lb/ft2 would be the upwards of 9.25 inches of snow-water equivalent stacked up on the roof. The area only gets about 25 in. of precip. in an entire YEAR!

We weren't sure how difficult it might be to raise the 2X12s manually, so we decided to cut and nail blocks onto the posts to support the rafters while we nailed them in place (so we wouldn't have to rely on our muscles for as long!).

A little trigonometry and a few miter saw cuts later, we had the blocks installed (you can see them in the previous post's photos).

We didn't order any extra 2X12s, so we were VERY careful about measuring and cutting them. Incidentally, the calculator said that each rafter should be 13' 5". Actual measurements (by stretching a flexible tape from the peak block to the eave block) came in within a 1/2" of that (except for the rear set, where the peak ended up nearly an inch off to one side). Not too bad for a couple of amateurs, if I may say so myself.

On the second try, we figured out a pretty easy way to hoist the rafters into place. We would stand them up next to the peak post and Mrs. MtnMan would climb to the top and guide them as I lifted the entire thing vertically. Once the top end was sitting on the block, I would carry the bottom end across and up toward the eave-post, then carry it up the ladder and set it on the lower block. The eave girt prevented it from sliding down and away. Then I just grabbed the nail gun and tacked it on. We could measure, cut, and install one every ten minutes that way.

After they were installed, I used a long boring bit on a heavy-duty drill (borrowed) to drill 1/2" holes in each post-rafter assembly. Into these I installed 1/2" bolts to firmly secure the rafters to the posts.

Lastly, she cut and installed some short knee-braces on the open-side posts to add a little stiffness. I think they look pretty cool, too.

At that point, we had run out of time for the long weekend. We were pretty happy with the progress, though, and will be back up there in two weekends to work some more.

Next steps: cutting the excess off the post tops, start roof framing. I'll update in a couple of weeks.

 

[ustmd]

Sidewall Framing:

The first step was to set a "zero" elevation for the entire structure. This would ideally be done with a spinning laser level that could hit all of the posts at once. However, we didn't have access to one and didn't want to invest in one powerful enough to work outdoors just for this project.

So, we simply went to the post with the highest natural grade (back corner), and tacked on a treated skirt board about 1.5" above grade (sitting on a 2X6 block, to be exact). Then we set the long level mentioned above on it sideways, adjusted until it was level, and tacked it onto the next post. We continued this process of tacking, leveling, and nailing the skirt boards to all of the posts around the enclosed side of the shed. As a cross-check, we laid the level on the skirt boards across the middle of the enclosed side on the opposite end of our starting point. This verified that we had not drifted off of level on one side vs. the other.

Nice build and thread.

What you did works great, but next time you run into this problem, may I recommend you invest in a roll of builders twine and a line level ($2.99 for a pack of 2). Not as sexy as a rotary level, but does the job.

[ame=http://www.amazon.com/Kapro-440-08-Line-Level/dp/B001N3H1P0/ref=sr_1_2?ie=UTF8&qid=1338322604&sr=8-2]Kapro 440-08 Line Level: Amazon.com: Industrial & Scientific[/ame]

 

[flusher]

Excellent job and thanks for the documentation in your thread. I build a 20x28 ft post frame shed a few years ago and went through the same process you used. Fun and games

 

[MtnManSK]

Rafter Blocking:

After a two-week hiatus, we were back at the Cabin last weekend and made a little more progress on the shed.

The first step was to haul the chainsaw up to the top of the posts and cut off the excess. I left enough to nail 2X6's to and tried to angle them with the roof pitch. However, not being a logger by trade, running the chainsaw sideways, at an angle, on a ladder, AND at about shoulder level proved difficult for me. I wasn't able to cut them exactly on the marks, but luckily it doesn't really matter because they will all be covered and nothing rests directly on the tops.

Next we needed to install the rafter blocking. These are 2X6s sandwiched between the rafter pairs and sticking up so that the purlins can be nailed to them and held upright and on edge. They needed to be 16" o.c. and approximately perpendicular to the rafters. Add to this the fact that most of the 72 blocks would need to be installed while on a ladder, and I knew that we would need something to ease the process. Thus, I built a simple "jig" that would hold the block in place (16" away from the one above, and perpendicular to the rafters) while we nailed it from one side. Then, the "jig" could be moved one block down for the next one. (see photo below) Last, we came back and nailed the blocks from the other side of the rafter pair.

This worked for all except for the top and bottom blocks, which had to be held in place by hand. However, those were a little easier because we had posts/framing to hang on to. In all, the blocking took an entire afternoon and didn't really look like much when it was done. But, it made the next step much easier . . .

 

[MtnManSK]

Purlin Installation:

Building this shed in "snow country", we decided to go a little on the overkill side with roof framing. So, planned for 2X6 purlins standing on edge, 16" o.c., spanning less than 8 feet. The only downside to this is that we're adding a little more dead-load than is necessary to the rafters, but I REALLY didn't want the roof metal sagging if we got a big snow that didn't slide for a few days.

We started with the middle bay and simply nailed the 2X6X8' boards onto the blocks, working our way from the bottom up. As we went up, we created a framework we could crawl/sit on to work. This went REALLY fast.

Since our roof metal comes in 3' coverage panels, we decided to make the total width of the roof (gable to gable) 27'. This would give us 18" overhangs on each end and prevent us from having to "rip" a panel lengthwise. We were trying to minimize cutting the steel panels.

Thus, for the front and back bays, we needed to measure and cut for each purlin so that the total roof dimensions would be correct. This took a little longer, but with both Mrs. MtnMan and myself working on it, we knocked it out the course of about half a day. We helped ourselves a little by measuring and writing down all of the lengths for a bay in one trip up onto the roof/ladder, then cutting them all, then installing them all. That required a little more organization, but reduced the amount of climbing significantly.

The result wasn't perfect, but with a little trimming in place with a circular saw, I think the facia boards will go on okay (and relatively straight).

That was as far as we got in a regular weekend (with some more rain and a few other obligations). We probably won't be able to do any more significant work until the weekend prior to the 4th of July. Next steps: outriggers and facias.

FYI: I thought I would mention here that two tools have proven themselves ABSOLUTELY indespensible in this project so far:

1) A Porter Cable FR350 framing nailer. We picked it up used (barely) for $90, but I'd have paid double that if I couldn't find a used one. It's extremely reliable, easy to use, and saves a LOT of hammer-swinging. It doesn't even use much air, running just fine on my small pancake compressor. The only downside is it's just a little heavy.

2) A Chicago Electric 10" sliding compound miter saw. We ordered one of these from Harbor Freight (made-in-China superstore) for $100 with a coupon. The first one showed up broken, so we exchanged it at the local Harbor Freight store, and this one has been flawless. It makes regular square cuts SO much quicker and easier than a hand-held circular saw. It also had enough capacity to cut our 2X12 rafters at the 26.5 deg. miter angle necessary. We set it up on planks and saw-horses under a shade canopy, and it has been VERY nice.