Today the first Nature’s Nest tiny house trailer was delivered from Tiny Home Builders. The arrival of the trailer has made planning much easier. I am looking forward to putting on the first layer of materials. Currently I am between two options for my subfloor sandwich. (If you’re looking for more information view this article.) The two options are as follows:
*Bottom to Top*
- Treated plywood (To hold KFlex sheets in place)
- KFlex Insult-Sheets HVAC Insulation (Will serve an extra R8 underneath the trailer’s subfloor.)
- Aluminum Galvanized Flashing stapled into subfloor framing
- Subfloor Framing: 2×4’s with Owens Corning Insulation (R22).
- Cabinet plywood (will serve as a floor for a while until later).
*Bottom to Top*
- Aluminum Roofing
- Subfloor Framing: 2×6’s with Wool Insulation (R25) or 2×4’s with Owens Corning Insulation (R22)
- Cabinet plywood (will serve as floor until later).
Both options will be fastened to the trailer using a lag bolt. (Just a note, I will also be using Simpson Strong Ties to connect the wall framing to the trailer, in addition to using these lag bolts for the subfloor.) What is holding me up in this decision is deciding what I choose for my aluminum flashing, what to choose for insulation, and if I am going to use a product called KFlex.
I was thinking of using this product called Kflex insulation with the galvanized rolls of flashing (it won’t work with the roof because of the roof’s ridges). KFlex is an insulation used on outdoor heating and cooling systems. After talking to the company, they said that the product would work, I just need to attached it to the aluminum with an adhesive and put a protective coat on the underside, or, put a piece of plywood above the cross members that will allow the Kflex to sit in the bed of the trailer.
I am still unsure about using this product because I want the aluminum to have the capacity to breath in case water gets in there. Also, I would the aluminum to serve as the protective barrier, rather than plywood.
What is holding me up about option 2 is how the roofing will fit in the bed of the trailer with its ridges and what to use for insulation. What I decide to use for insulation will determine what I frame the floor with. I am trying to decide whether or not I should comprise two inches of headroom in the interior space by using a 2×6 for the floor framing which would allow me to gain an extra R8 I need to meet an R30. I am leaning towards using a 2×4 because I’ve heard that it doesn’t matter your Rvalue or what you use, it all depends on how well you insulate it.
Tomorrow I am attending a home show in my local area to have these questions answered. Please leave a comment if you have any suggestions for how I should make my subfloor sandwich!