Wall framing complete!

Rob and I finished framing out all the walls yesterday! We had quite a few pieces to add since our last post… studs we had left out to make screwing easier, window supports, the other gable end, the loft etc.

We also added a couple of pieces of sheathing last weekend, with the help of our friends Casey & Eric (who is a screwgun master). This weekend, we finally figured out what the jigsaw is perfect for — cutting out the window rough openings in the sheathing.

Our painted subfloor is holding up great! It’s been raining almost everyday, but there hasn’t been any lamination or warping.

Up next, roof rafters (I’m a little scared)!

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Finally, it looks like a house!

Look!! We have some walls!!

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Rob and I have been working on framing the walls in the comfort of our garage for the last few weeks. This past weekend, we were finally able to put them up! They are a bit heavy, and it’s difficult impossible to manage measurements and placement with only two people. Luckily, we were able to find some magical internet friends!

Thanks a lot /r/321!! With the help of Cheryl, Price, Amanda, Ellen, Mike, Casey, Eric, Ronnie, Adam, and David (I hope I got those all right… and I can’t forget Brandon, Jade, and Bear), we got all four walls standing and braced. We also celebrated a birthday, and our dog Proton made a friend!

I’m so excited — it really seems like a tiny house now!

Steel Framing

I’ve had a lot of people ask me why we went with steel instead of wood… it definitely has advantages and disadvantages, but overall, I’m very happy with our decision.

The good…

  • Ease of use: The steel is soooo nice to work with — none of the pieces are warped or twisted like with wood, and it really seems like you can get things exactly right if you’re willing to do careful measurements. We were amazed how well everything fit together when we put the walls up.
  • Recyclability: Steel studs are made of largely recycled materials, and the scraps (or the entire structure eventually) can be recycled. [1]
  • Termite resistance: Termites are a big deal down here — we didn’t want our entire house structure to get eaten.
  • Strength & weight: A steel stud is lighter than a similarly sized wood stud. The difference isn’t huge since we’re using 18 gauge steel (some people use the lighter 20 gauge, but this doesn’t meet wind load requirements for our area), but the steel has more strength for its weight.

The bad…

  • Price: I’ve heard that steel and wood are comparably priced — let me tell you, that’s not true around here. I found only one local company selling 18 gauge steel studs, and they were about twice as much as lumber. The fasteners are also more expensive.
  • Possible rust issues: Things rust super fast down here… we don’t think this will be an issue with the galvanized studs, but it could be. Everywhere we make a cut or hole, we use a cold galvanizing spray to protect the bare metal.

Besides that, steel just seemed really cool! I worked on iron and steel for my entire PhD and postdoc, so it’s somehow more personal to me! If you’re considering steel, check out some of the references at the bottom of this post, and definitely consult the Prescriptive Method for Residential Cold-Formed Steel Framing [2] for load tables and lots of helpful diagrams.

Another consideration for steel framing is insulation. Steel acts as a much better thermal bridge than wood, which means that standard “between-the-studs” insulation isn’t very effective. [5] The best method to deal with this is to use continuous insulation on the outsideĀ of the steel. This changes the design a little bit from the typical tiny house, but it leaves the space between the studs free for easy plumbing, wiring, and even shelving. More on that in a few weeks…

Leveling & attaching the scissor jacks

We finally got our scissor jacks on the back of the trailer so that it could be leveled before the walls went up. We decided to attach them using bolts instead of welds — that way, we can remove them for transport to get better ground clearance.

In order to have the bolt heads be accessible (so they don’t turn while you’re tightening the nut), we had to go through several layers — the trailer itself (a 6 inch hollow piece of steel), the floor framing, the subfloor, and the bottom layer of track of the wall. This required super long special-order 3/8″ bolts:

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When they arrived, we saw they were only threaded on the bottom bit, and they were a bit too long (you don’t get to be very specific in lengths when you get to foot long bolts), so we added some spacers too. Since the holes we had cut in the steel track were rough & large (so they’d fit over the entire nut), we went back and added steel plates to strengthen things, then we caulked around the edges to prevent water penetration. When the walls go up, we’ll still be able to access the bolt heads from inside the storage area in the couch.

We do plan to add two more scissor jacks in the front — those corners are noticeably bouncier than the back ones now.

We have a little bit more framing to do (some studs we left out for ease of screwing, loft, etc), but luckily we got most of the heavy pieces in place! More importantly, we made some local friends that I hope we’ll see a lot more of šŸ™‚

 

References

[1] SSMA — Green Building

[2] Prescriptive Method for Residential Cold-Formed Steel Framing

[3] Highly recommend this book: Steel Frame House Construction (also includes a copy of the Prescriptive Method)

[4] Buildipedia article

[5] IMPROVING ENERGY PERFORMANCE OF STEEL STUD WALLS, ORNL

Subfloor v2.0

In my last post, I detailed a few problems we were having with our subfloor…

The tarp-tent was a total fail, and we took it down after a few days… the wind kept blowing down our cement bucket poles, and small holes meant that water was still getting in (side note: never buy a 30’x50′ tarp, it’s completely unmanageable)… the wood couldn’t dry when the rain stopped, because the tarp trapped it in. The last straw was the termite family we saw munching the veneer in one of the corners. We decided to try our luck with the open elements, but the waterseal didn’t really stop the delamination which occured from being rained on everyday, and eventually it got so bad that we realized we just couldn’t salvage this floor:

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This time, we’ve used some of the plywood we had designated for our sheathing. It’s rated Exposure 1, which theoretically means it can weather being rained on quite a bit… but we’re now paranoid, and we know that if this second subfloor fails, we might really just give up.

So, we decided to go a bit farther, painting it with Olympia Rescue It! wood & concrete resurfacer. It’s pretty thick stuff with a nice gritty texture. It can even fill holes up to 1/4″, which was nice since some of the plywood had some big knots. Although we’ll eventually be covering it with something else, it requires a tint to mix properly… so we chose an exciting color that should make us feel energized to look at. Can you believe they call it Muted Mesa?

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After getting all the screws out of the old subfloor, we had to pull it up. This was initially a bit of a challenge, since we conveniently glued it to the framing. To cut between the layers, first we tried the jigsaw…

Yeah… no. We keep trying to use the jigsaw, but we haven’t found it’s magic application yet.

Our old friend the circular saw came to the rescue!

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And then it electrocuted me…

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Just a little bit. There was a worn part of the sheathing on the cord, and it zapped me in the lower leg. I felt a bit tingly for a few minutes, but I’m alive…

Luckily, beyond the first board, we didn’t have to do much cutting. Usually if we cut the glue onĀ  one side, we could pry up the rest of the board. The glue was apparently working well on some parts, but (luckily) not so well on others.

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Everything looked pretty decent underneath, although there was some water sitting on the insulation in a few places — all near the breaks in the subfloor, where warping had allowed water to flow in. Bad… but not that bad. We let it dry for a few hours in the sun.

Finally, we got the new boards on! They are only 15/32″, instead of the 3/4″ we had before. There is a noticeable difference in sturdiness & flexibility, but since we’d used 16 OC joists, it’s still workable.

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We also learned that we’re supposed to leave a 1/8″ gap between the sheets to allow for a little bit of expansion & contraction (we didn’t do this on subfloor #1)… but again, we’re paranoid, so we also filled in that gap with Rainseal caulk. And then we filled in every other gap and screw head everywhere with it as well. That will hopefully stop water from getting into the framing & insulation at all.

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We’ve been very hard at work on framing the walls, from the comfort and safety of the garage (yay ceilings). We’ve got those mostly ready to put up, but they are a bit much to manage with only 2 people. So, we’re hosting a house raising BBQ next weekend! We don’t have any nearby friends yet, but we’ve managed to recruit about 15 people from our friendly, local subreddit, r/321! I’m really looking forward to meeting everyone next week and getting our house to the point where it actually looks house-like!

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