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Tiny House Subfloor: Part 2: Mediocre Flashing Job

Shitty McShit Shit

Shitty. That’s how I feel about my flashing job. It was the first thing I put on the trailer too! I was too excited and too determined, and I didn’t have Michelle to problem shoot with…so it didn’t turn out very well.  Learn from my mistakes…let there be a positive side to this! When everything was said and done, it ended up not being as shitty; maybe even decent.

Inspector Charlotte: "Not your greatest work Chris...but the shade is nice."
Inspector Charlotte: “Not your greatest work Chris…but the shade is nice.”

Materials:

*Would recommend using butyl rubber flashing tape (the stuff for windows) instead of UL tape.

Tools: 

  • Wiss Multi-Purpose Snips
  • Drill with 5/8 or 3/4 inch Drill Bit

What’s the Purpose?

Do you want mice and creatures eating your subfloor? Do you want an added layer of moisture protection when parked or driving down the road?What about an initial layer of protection from road debris? If the answers are yes, metal flashing is a great solution. Some tiny house builders have used just 3/4 inch exterior T&G plywood with strong marine exterior paint.  We decided to utilize a combo: exterior plywood with metal flashing. Ryan Mitchell’s article is a great resource for this step, too.

Laying Down the Metal

Before you begin, check out the “Reflections, Hindsight, and Alteration” section because I would have just boughten five 5 ft x 10 ft galvanized flat metal sheets for $100-120 dollars on craigslist, which would have been better protection, a lot less hassle, and cheaper, but I digress…I’ve seen a couple of approaches to applying the flashing. Some tiny house builders will have enough space to lay all the metal down on a large floor as if it was on the trailer. Then they’d tape the metal or fasten it to their plywood while it’s on the ground. How nice to have such a space! Or, others have their flatbed boards on their trailer. This allows them to fasten the metal flashing with staples or galvanized nails to the wood. How nice! For this no space, no boards, and anxious to build guy–it was laying the metal on across the top and hoping the 3/4 inch plywood would flatten it out.

Not ideal but on.
Not ideal but on.

Shit Show Special

I had to buy more metal flashing twice (final count is the one above). Marking the holes for the bolts and drilling into the metal wasn’t ideal, but it worked out.

 I thought the UL listed tape would totally hold the wavy seams, but it was breaking a part as much as my heart!
I thought the UL listed tape would totally hold the wavy seams together, but it was breaking a part as much as my heart!

Should have used butyl rubber flashing tape. I overlapped the seams by 2 inches (that’s just how the overlap worked out when dividing my 8.5 ft trailer by 20 inches). Before applying the tape, I would silicone between the flashing sheets for an extra layer of moisture protection in addition to the tape. I added 1-2 inches of metal overhang off the ends and sides, thinking I’d attach it up to the subfloor. Then, I found out that this would be stupid because it would trap water and bring water in-between the flashing and 3/4 inch plywood, so I ended up cutting it off with the angle grinder (which was a slight pain, so save yourself the trouble).

Adding Work: Needless overhang that had to be cut off.
Adding Work: Needless overhang that had to be cut off.

Cover Up!

The tar paper went quick. The tar paper will be added moisture protection. If you use aluminum flashing, it’s crucial to separate the aluminum from your pressure treated plywood with tar paper; otherwise, they will negatively react. One of my friends recently mentioned that it might have been good to add some liquid tar between the galvanized metal and trailer–preventing them from corroding. I didn’t do this, but I hope the paint on the trailer adds that needed layer of protection.

Adding More Work

As you can see, adding the 3/4 plywood didn’t solve my wavy problem. Frustratingly, I needed to take care of these gaps.

IMG_2590
Wavy on the Bottom

IMG_2589
Up to 1/2″ gaps with those waves. Yikes.

My solution to the waves was adding more silicone and using really short Tek roofing screws (#12 x 3/4 in. Fine Metallic Steel Hex Drill Point Roofing Screw) so I wouldn’t go too far into the 3/4 plywood. I had to buy five things of silicone and five boxes of screws (an extra $85 in the end).

SSS Approach: Screws and Silicone Salvage
SSS Approach: Screws and Silicone Salvage

IMG_3177 IMG_3178 IMG_3179

Even though it was a rocky road, I have achieved the flashing’s purpose: moisture, road, and rodent protection. Definitely a lot of lessons learned on this step.

The reins are ours,

Chris

 

Reflections, Hindsight, and Alterations:

  • Use flat 5 ft by 10 ft sheets. Would be stronger and thicker metal protection. Wouldn’t have to worry about wavy metal with my trailer setup. Would have been even cheaper in the end with prices I saw on craigslist!
  • Use butyl rubber tape instead of UL Listed tape. Butyl rubber tape is a great moisture barrier and very sticky and a lot wider (usually 6 inches). This would have been the better choice.
  • One way to prevent the waviness could have been to create a metal joint by bending the metal edges. This would have eliminated the need for any tape or silicone at the seams, too.

    metal joint
    Metal Joint Solution
Categories: Building

Tiny House Subfloor: Flirtatious Beginnings: Wood Meets Metal

T&G: Tangible and Gnarly Plywood

After receiving our lumber, the plywood and wood needed to be acquainted, so we left the plywood on the trailer for a week to see if they liked each other…any gullible readers? I hope so. The first step was to correctly cut and lay out all of the plywood on the trailer without the obtrusive bolts complicating things (I’ll weld them on later). I mapped out two ways to lay the plywood efficiently. I did this before purchasing the lumber to help calculate my plywood count.  I ended up using a slightly adjusted “longitudinal” approach to make sure the plywood seams ended up on the trailer’s metal joists.

Trailer Dimensions:

Trailer Schematic
Trailer Schematic

Orientation Option 1:

tandg plan
Lateral Option

Orientation of Plywood Option 2:

Longitudinal Option

Confession: Permit-less Punks

If your trailer is a typical eight foot wide one, it’s a lot easier to lay out your plywood. Our trailer is wonderfully and awkwardly eight ft, four and 3/4 inches. With our roof overhangs we will be pushing the state’s limit of 8 ft, six inches. Because we rarely plan to move the house, we’re comfortable with pushing the width limit to gain as much interior space as possible. Will this “inch pinching” decision come back to haunt us? I hope not, gulp!

The Beginning of Endless Wood Cuts

Ignoring 100,000 demanding future cuts for the house, I emphatically engage with the initial large and heavy plywood puzzle.

Tools:

  • Circular Saw and Jigsaw
  • Powered Drill with Your Bolt Size Bit (5/8 in) *A little bigger
  • 4 ft and 2 ft Square
  • Cutting Guide with Clamps

Plywood Puzzle
Plywood Puzzle

Jigsawing the Wheel Well
Jigsawing the Wheel Well

It fits!
It fits!

Turmoil Already

Unbeknownst to me, after the wheel wells–the trailer starts to taper as you approach the angled hitch area! So, it wasn’t square and flush with my plywood’s factory edge pieces–which was really throwing me off. I thought the whole trailer might be out of alignment and warped. Panic anyone? Because my glass is half full, the trailer tapers only a half an inch on each side gradually over the last four feet–not so bad, so instead of moving the whole house’s frame inward, I tossed the dice, letting it hang over (the bottom plate will still be 85% on the steel frame and bolted to it). Surprisingly, the turmoil led to an idea.

Inch Pinchers Become Foot Pushers

“This overhangs. Why not gain some feet in the front? Extend the overhang!” exclaimed Chris.

“Wow. The extra feet would be nice! Would it effect turning and driving the trailer?” Michelle said.

“That’s what I was wondering about…I don’t know. If we only do two feet, it shouldn’t, but I don’t know. Should we go for it?” Chris said gazing at the hitch area while day dreaming about even more space.

“Yea!” Michelle said…day dreaming about more space.

Let’s hope our space ambitions really don’t haunt us–but yes, although in all of my tiny house research I have never come across any instances or examples of it, Michelle and I have taken the risk of expanding the house over the trailer two feet. This will give us 22 ft total. The angled steel framing near the hitch is four feet in length, so we’ll still have two feet–hopefully this is enough for all turning we’ll need to do on the road.

The Dice Keep Rolling: Extending the House
The Dice Keep Rolling: Extending the House

Bolt Holes

Finally, I drilled holes where I plan to weld the bolts. Had to buy a drill bit that was slightly larger than the 5/8 inch threaded rod. Initially, I was using a 5/8 inch bit and spinning it around to make a larger hole–not something my arm wanted to do sixteen times–doubt the drill liked it either.

Always ruining things with  holes!
Always ruining things with holes!

The reins are ours,

Chris

Reflections, Hindsight, and Alterations:

  • Although the extra space will be nice–the extra width may cause a lot of problems while driving–and it makes more wood waste because it’s over eight feet. Would have enjoyed an eight foot wide trailer for its simplicity.
Categories: Building, Design

Tiny House Trailer Bolts: Welding Went Well

Calling All Local Welders

“Yea, how much would it cost to weld threaded rod to a trailer for a tiny house? Like sixteen pieces.”  Tiny house enthusiasm ensues. Confusing welding terms are shared. Various prices are quoted.

quotesTenacity for Learning or Stubborn Frugality

The price sounded like it would cost around $250. As a growing DIY guy, I’m more and more reluctant to hire help. I’d rather learn the skill–and overcome my reservations and fears about trying it. Welding the rod to the trailer was a prime example of this tenacity for learning (the nice spin on the behavior).  The decision was finalized after talking with two friends who have welded before. They confirmed my pa’s MIG welder should do the trick–or at least I should try it and see how strong the welds would be.

Enter the MIG Welding Unit

Pa purchased a 90 Amp Flux Wire Welder by Chicago Electric from Harbor Freight for $115 awhile back. It states that it’s not suited for aluminum or stainless steel. I forget what threaded rod we used–but I hope it wasn’t stainless now! They have a stronger unit that does stainless steel for $199.  These units don’t require gas–they eject heated-up metal as they make their arc, which is when you use electricity to heat metal to bond the two metals. Like all welders–these puppies need to be grounded and emit dangerous levels of electricity–all precautions should be taken.

See what this little guy can do!
See what this little guy can do!

Welding Preparations

You shouldn’t weld over paint–nasty smelling and it will compromise the welds, so after grinding down my beautiful paint job, I marked lines on each side of the threaded rod after making sure the rods were straight up and down and level.  I also precut all of the rods. As stated before, I had 6 inches of steel tube framing and 6 1/2 inches of subfloor with the sill plate. I added another two inches for a buffer and to have enough for the Simpson Strong Tie HTT5 to fit over. I rounded up and went with 15 inch pieces, so I would need 20 ft of threaded rod ($60-70 depending on grade and type).  *I cut off around 2-3 inches in the end, so I had too much.

Simpson Strong Tie HTT5
Simpson Strong Tie HTT5

Tools:

  • Welder
  • Welding Gloves
  • Welding Mask (Automatic preferred) *Check batteries in it!
  • 10 Gauge Extension Cord. We used a 12 Gauge Extension Cord.
  • Stronger Welder Might Need 30+ Amp Plug. Our 20-amp did the deed.
  • Cheap Steel Brushes
  • Extra Welding Wire Spool. We used two spools.
  • Slag Chipping Hammer

Materials:

  • Cut Pieces of Threaded Rod

Advice from Ollie

One of my friends with welding experience gave me the following tips and expectations and also led me through a welding practice session at his workshop:

  • With the MIG welder, you’ll be using Flux Core Wire. This is messy. Will create slag (black glassy layer stuff) which you’ll have to chip off or scrub with a wire brush. Use non-flammable clothing because this stuff with spray you a bit. *Followed advice and got sprayed quite a bit. I didn’t need hammer to chip off slag; the steel brushes were enough.

  • Your welder has lower amperage, so you won’t be able to fine tune its setting as well as other welders. You’ll probably need it on max. Adjust the wire feed to get a nice bacon sizzle that doesn’t shoot off too much slag. *Yes, it was on max, and the wire feed was around 8. This was high because we had a large gap to fill in.

  • Make sure to have a strong extension cord. *Got one.

  • I looked at your welder’s manual. It has 220% duty cycles, so after every 2 minutes of welding, you’ll have to let the welder cool for 8 minutes at its max power setting. *We rested it for about 5 minutes. Pa wasn’t patient.

  • You can use zinc primer for the welded area. *Didn’t use. But after cleaning the welds, I did quickly use rust converter as a primer (otherwise surface rust would occur overnight).

  • Use a mask for zinc vapor, or you’ll get metal fever. *Yikes–I wore my respirator; never got a crazy fever.

  • Take a sledge hammer and hit the rod after. If it holds, you should be fine. *We did this—hit the rod multiple times to really test it. They were holding very well! Yay! Also, I had to sledge some of the rods a bit when putting the 3/4 inch plywood over them.
Pa Starting Off the Welds
Pa Starting Off the Welds

Threaded Rod Placement

I didn’t have to weld along the height of the whole steel tubing (6 inches), but I thought it was a nice overkill idea.  My friend Ollie explained that the more space in-between the metals, the more you can inject metal into that in-between area, bonding the metals while creating a stronger weld. For this reason, I chose to run the welds along the entire tubing instead of a butt weld (just placing the rod on top of the trailer framing–little surface area between the metals ). I heard butt welds can be sometimes finicky and unreliable, too….probably depends on the welder. For me, I was going for maximum strength; however, placing the rod along the tubing shifted the holes in my sill plate–they wouldn’t be in the center of the plate anymore, but it would still work out, so “I made my bed to lie in.” One alternative option would be to drill a hole in the frame. Place rod into the hole–weld around the top of it. You also could add an additional hole and welding point through the bottom of frame.welding rod info

Ugly but Strong Welds

Pa started off welding the first side of the trailer. He owned the welder and had a little experience.  He’d weld a small bead at the top and bottom while I held the rod in place. Then, he’d start filling in the entire length (my overkill request). His initial welds were pretty ugly tumors; sorry Pa. This was because we didn’t have a high enough setting on the wire feed for the large gaps we had to fill in. Also, Pa didn’t really get the welding gun in close enough for that nice consistent bacon sizzle. We’ll place the blame on his glasses. Regardless of looks, we banged on them with a lot of force with the sledge hammer–they weren’t budging or going anywhere! Success!

Tumor Welds
Tumor Welds
Tumor Style Welding Contiunes
Perfect Tumor Welding..
Wow. Our welds are ugly.
Wow. Pa won’t be getting any beauty points.

Round 2: Just Me and the MIG

We didn’t finish all of the welds on day one because it started to rain. On day two, it was just me. Before I got started, I noticed that surface rust already started to form on the bare metal areas. I should have applied a metal primer or the rust converter as a primer ASAP yesterday. Lesson learned.

Rust Already.
Rust Already.

After cleaning off the rust and putting on the rust converter, my welding debut commenced.  I read through the welder’s manual, and I made sure I followed all of the safety steps. Definitely make sure to ground the welder with the clamp. We would use the previous bare metal bolt to do this (a painted surface could weaken the ground connection).  I held the rod myself and got some beads on it. I found that if I got the needle closer and slowly weaved left to right, I could get some less ugly welds. I felt a little giddy during the process! I didn’t have to hire a welder and picked up a new skill. I hope to weld some furniture legs in the future (you can always grind down those ugly welds!). Don’t forget to prime and paint the new bolts! Here were some of my less ugly welds:

IMG_2577
Not as ugly welds.
IMG_2575
Not too shabby.
IMG_2574
A Welding Machine

The reins are ours,

Chris

Reflections, Hindsight, and Alterations:

  • It’s really helpful to reach out and see if you have any friends who can weld.
  • If you don’t want to invest in the welder or can’t find one to borrow, cut the threaded rod with an angle grinder with a metal cut-off blade. Having the rods prepared will cut down the cost of having a welder come over.
  • After placing the steel hold-downs over the rods, I ran into some issues. Because the rod wasn’t in the center of my sill plate, some hold-downs would stick out slightly beyond the thickness of the wall. I could either grind down the hold-downs or just carve the back of my pine siding to make it work.
  • One rod was in the middle of our door! I put a nut on the bolt and shaved the rest of the rod off. I was able to carve a piece out of the bottom of the door frame to fit it over the nutted bolt, allowing me to utilize that bolt to help me at least hold the subfloor to the trailer at that point.
  • Between a lot of welding overkill along the 6″ steel tubing and cutting off 2-3 inches at the top– I wasted a lot of threaded rod. Shit. Should have just welded 3-4 inches along the frame and trusted my measurements to and above the sill plate. Don’t forget to add the Simpson Steel Hold-down built-in washer and height of the nut. I’d add an inch of wiggle room beyond that get more.

 

Categories: Building, Uncategorized