Saturday, August 24, 2013

Tiny Home Building: Floor Specs

I managed to take some pictures of the supplies/accessories we used for the floor frame. 
These are the 3/8" carrage bolts we used for bolting the three frame pieces together. Plus the nuts and washers. I went with thick ones so that we could use fewer and I thought they would hold it better. 
These are the heavy duty angle connectors we used to secure the frame to the trailer. These were pretty much the strongest ones they had. 
And here are some of the nails/screws we used. The top left ones were used for the angle connectors, the top right ones were used for our angle brackets (see below), then you have the 3" nails we used to put the floor frames together, and the roofing nails that we attached the flashing to the frame with. I actually found some 1" roofing nails in my dad's garage that turned out to be a lot easier to nail in so I would recommend 1" ones as opposed to those 1 3/4" roofing nails. And the reason I chose these was because they have plastic caps that don't allow water to seep through the holes that are formed when you nail them in. I definitely wanted that because the reason to put the aluminum flashing down in the first place was to stop water! So I thought that was pretty important for the integrity of that protective layer. 
This is the subfloor adhesive we used to glue the plywood down to the floor frame. This creates a seal and helps to keep the plywood where it's supposed to be (which is also said to eliminate any squeaking you might have). We got the 28 oz ones because it was cheaper than buying more of the smaller ones... even with buying the larger size caulk gun included. 
And just some loot that I found in my dad's garage. I don't think he knew he had half of this stuff in there! I found a ton of insulating foam, nails, and a butt load of screws! Yay free stuff! (P.S. I made sure to ask before I took all of this stuff..... just to be clear that I didn't steal it all!)
And here are the angle brackets. I don't think I mentioned this in my last posts about putting together the floor frame but we used these at every corner of the frame just to give it some extra stability. You can see below. 
(3" screws, two per floor joist. Don't forget to drill pilot holes when using screws to avoid splitting the wood!)
Here you can see the flashing we used. We went with a 20" wide x 50' long aluminum flashing. We used three rolls and it was juuuuuuust enough. To seal the edges together, we used Loctite roof and flashing sealant
You can see the angle connectors at work here, holding the floor frame to the trailer. One for each joist, alternating sides. 
And the bolts that we used to connect the pieces of the frame together. We used a super long 1/2" bit to drill holes first and then used a regular old wrench to tighten them. 
Here is the second method we used to attach the frame to the trailer. So our trailer had these little cavities on the side of it as you can see below. Instead of removing them, we decided to use them to our advantage! All the credit goes to my dad for thinking this one up, he's kind of a genius. 
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You can see how they are hollow on the inside. So the idea that my dad thought up was to cut a piece of metal that would cover the hole right there. Then screw a lag screw up into the piece of metal and into the frame above. 
However, because the frame went out further than those pieces that rested on the side of the trailer and those pieces didn't line up the the floor joists, we had to put in some extra pieces of wood right above them as you see below. 
The pieces of wood lay in between the joists and are placed just above the edge of the trailer, directly above the cavities. And there are 4 of these on each side.... this floor frame isn't going anywhere! 

The 1/2" rigid foam insulation has an r-rating of 3.2. The Ecotouch Fiberglass insulation is r13 so that equals r16.2 which is a good rating for the floor. We used 5 sheets of the rigid foam insulation and 4 rolls of the Ecotouch insulation. 
Also, a little trick I picked up while applying the plywood was to mark on the side of the frame where the joists were. So when you put the plywood on top, you could see where the joists were and screw the plywood down into each one. I marked where the joists were on both sides of the frame and then once the plywood was on top, I snapped a chalk line all the way across the top of the plywood. That is what I was doing in the pictures below. 

24' Custom Trailer $2704
3 rolls of 50'L x 20"W Aluminum Flashing $124.02
7 Sheets 3/4" Plywood $105 
1 lb 3" Steel Screws $9.37
30 2 x 4 x 8 Yellow Pine Lumber 77.10
6 2 x 4 x 12 Yellow Pine Lumber 27.24
1 lb Roofing Nails $6.98 (I got 1 3/4" but suggest getting 1" instead)
12 Gusset Angles $8.88
#9 Connector Screws for Gusset Angles $10.63 
4 2 x 4 R13 Ecotouch Insulation $51.2
5 sheets 4 x 8 x 1/2" Rigid Foam Insulation $49.9 
15 Z-Max 12 Gauge Angle Connectors $37.95 
2 #8 Strong Drive Screws for angle connectors (one half off) 13.47 
13 1/2" x 4" Galvanized Hex Bolts $24.44 (return extra)
15 1/2" Washers 4.95 (return extra)
15 1/2" Nuts 5.7 (return extra)
U-bolt 1.7 (return)
3 Liquid Nails 28 oz Subfloor Adhesive $13.68 
28 oz. Caulk Gun $8.97
8 3/8" x 5" Lag Screws  $20
6 Loctite Roof and Flashing Sealant $35.1 
2 Gaps and Cracks Insulating Sealant $7.96
Total: 3348.24
4 Construction Pencils $.76
Utility Glove $9.97
2 1/2" deck nail $4.78
2 drill bits $5.94
Chalk line $7.87
3 aprons $2.94
mini peanut butter cups (bribe for eliza) $1.88
Mechanics Gloves $14.99
Total: 49.13
Tax: 48.08
Total: 3445.45

Floor Layout
Things to consider when building the floor: 
  • Will you be building around the wheel well? 
      • If so, how far past the edge of the trailer are you building and will that be stable? 
  • What kind of insulation and what r-rating do you need for your floor? Since air can move underneath you trailer, you will need adequate insulation on the bottom. 
  • Are the joists going to be 16" or 24" on center? 
  • What thickness will you need for the subfloor sheathing?
  • How will you attach the floor to your trailer 
  • In my research I've found that it's best to put your flooring perpendicular to your flooring joists. So you have to decide which way you want your flooring to run. 
  • Consider plumbing and where your bathroom will be. 
  • Are you going to build the bottom in three sections? 
  • Make sure there is a strong seal on bottom so nothing can come up through floor.
  • Make sure to cover it well between building days so rain doesn't leak through the floor and into the insulation. 
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