Questions before i start my house build

[thefarmer]

I want an ultralite fish house to use as a utility trailer in the off season, I can't find the design I want at the weight I want so I am gonna attempt a build. I had a few questions before I get started.

The trailer I am considering using has .040 aluminum on it. If I spray foam it will it get wavy? I am considering using board foam to prevent this and also as a backing for the thin Maynard's tongue and groove.

Any concern with the 5/16" t&g if I don't have backing behind it? Worried it might be too weak? Planned on furring strips 24" o.c. over the aluminum walls.

Thanks for the input.

[Hawg]

I don't have backing on my 5/16 but a toy hauler will take a worse pounding than just a house. If you were to build the house finishing the inside first like some guys do and foam the inner wall, then sheet the outside I wouldn't have any worries. You would be solid as a rock then.  Utility trailers/toy haulers sometimes take a heavy pounding.

[thefarmer]

Thanks hawg, should have mentioned I plan on buying a shell, yetti, firebrand, but most likely a ridgeline. The inside out approach would be ideal I think but I don't have that option unless I could find a skeleton frame.

[Moon Lake Refuge]

6 minutes ago, thefarmer said:

Thanks hawg, should have mentioned I plan on buying a shell, yetti, firebrand, but most likely a ridgeline. The inside out approach would be ideal I think but I don't have that option unless I could find a skeleton frame.

Do you have a garage or shed to build in or are you doing it outside?  If inside definitely build inside out.  If outside and you can find a solid week or two with little to no rain and have a tarp for days that does I would still build inside out.  We foamed right onto our sheeting and have very slight ripples at the studs but to be honest, the greater insulating and structural hold of sprayfoam vs foam board makes it a no brainer for me.  Sprayfoam every time.  Just reread that your buying a shell... Could potentially just ask them to frame it up and let you do the sheeting and insulation if  your worried about ripples.  They may cut you a deal on it?

Edited March 11, 2016 by Moon Lake Refuge

[Hawg]

Even 5/16 is pretty solid when it's T&G. I guess it just depends on how heavy and abusive you are on a trailer. Handlebars on a 4 wheeler would probably mark it up pretty good if they hit a weak spot.

[Moon Lake Refuge]

You could fix some threaded plates in a few spots on the walls to attach OSB in the off fishing season for protection against utility work and have fresh walls each winter?  Would likely need some kind of barrier between them to prevent scratches.  May be more work than its worth but depending on what you need a utility trailer for could mean many things.

[thefarmer]

Dealers are pushing to move their in stock inventory so I am kinda stuck with a shell that is on the lot to get a decent deal. 

I talked to a trailer sales guy and he claims they put tyvek or rosin paper in the bays to prevent the waves from the foam. Seems like it would eliminate most of the structural element of the spray foam. Plan b would be board foam sealed with can foam and also double as a backer for the t&g. 

It will only be a 6.5 by 12 or 14 so it shouldn't take much to heat but I hate drafts.

[Moon Lake Refuge]

If your putting a ramp on it your likely to get some drafts anyhow unless you possibly do a good semi permanent seal for the winter.  You still get structure even if it doesn't stick to the sheeting, just between the studs helps.  One of the guys who quoted our foam said 1/4 inch folding foam board helps prevent waves.  Don't know how much truth to it but may be worth investigating.

[thefarmer]

I have insulated window covers in my big house, they button on and even keep ice castle windows from being drafty!  Figured I get one big enough to cover the whole drop door.

Edited March 11, 2016 by thefarmer

[Lip_Ripper Guy]

5 hours ago, thefarmer said:

I want an ultralite fish house to use as a utility trailer in the off season, I can't find the design I want at the weight I want so I am gonna attempt a build. I had a few questions before I get started.

The trailer I am considering using has .040 aluminum on it. If I spray foam it will it get wavy? I am considering using board foam to prevent this and also as a backing for the thin Maynard's tongue and groove.

Any concern with the 5/16" t&g if I don't have backing behind it? Worried it might be too weak? Planned on furring strips 24" o.c. over the aluminum walls.

Thanks for the input.

The siding will get a little bit of texture to it, but it won't be terrible. I would not do tyvek or any sort of poly to prevent this, even though it will help.  1/4" fan fold or 1/2" foam board will work well. Glue it to the siding, and spray foam over.  This method will still help give additional strength. 

Make sure you run your furring strips horizontal, and I would recommend 16" rather than 24". Have the face of the studs sprayed over in between furring strips. With the 5/16", leave at least a 3/8"-1/2" expansion gap on all sides. It will be covered by a trim piece, and will help out with expansion and humidity  

The other thing I'm going to suggest is something new you'll see on my next build. 1/2" foam board on the inside of the furring strips. It should cut down even more on thermal transfer from the metal studs. 

[thefarmer]

4 minutes ago, Lip_Ripper Guy said:

The siding will get a little bit of texture to it, but it won't be terrible. I would not do tyvek or any sort of poly to prevent this, even though it will help.  1/4" fan fold or 1/2" foam board will work well. Glue it to the siding, and spray foam over.  This method will still help give additional strength. 

Make sure you run your furring strips horizontal, and I would recommend 16" rather than 24". Have the face of the studs sprayed over in between furring strips. With the 5/16", leave at least a 3/8"-1/2" expansion gap on all sides. It will be covered by a trim piece, and will help out with expansion and humidity  

The other thing I'm going to suggest is something new you'll see on my next build. 1/2" foam board on the inside of the furring strips. It should cut down even more on thermal transfer from the metal studs. 

So your gonna put 1/2" foam board between the aluminum stud and your furring strips? Making for a finished wall of 1/2" foam 3/4 " fur strip and 5/16" t&g? Have you felt cold spots in your last house without the foam backed strips?

[Moon Lake Refuge]

16 minutes ago, Lip_Ripper Guy said:

The other thing I'm going to suggest is something new you'll see on my next build. 1/2" foam board on the inside of the furring strips. It should cut down even more on thermal transfer from the metal studs. 

Never thought of that... Would also give you more room for different types of outlets/fixtures without having to cut out to much insulation.  You think that will structurally hold as sound as going straight to the studs?

[Lip_Ripper Guy]

4 hours ago, thefarmer said:

So your gonna put 1/2" foam board between the aluminum stud and your furring strips? Making for a finished wall of 1/2" foam 3/4 " fur strip and 5/16" t&g? Have you felt cold spots in your last house without the foam backed strips?

No. The foam board will go on top of the furring strips, between the furring strip and the 5/16 t&g. 

No cold spots, just trying to make it as efficient as possible. 

4 hours ago, Moon Lake Refuge said:

Never thought of that... Would also give you more room for different types of outlets/fixtures without having to cut out to much insulation.  You think that will structurally hold as sound as going straight to the studs?

It should be fine. I'll glue the foam board to the furring strips, and probably glue the 5/16 to the foam board. Haven't decided just yet. I'll see how it looks when it starts going together. 

Edited March 12, 2016 by Lip_Ripper Guy

[thefarmer]

29 minutes ago, Lip_Ripper Guy said:

No. The foam board will go on top of the furring strips, between the furring strip and the 5/16 t&g. 

No cold spots, just trying to make it as efficient as possible. 

It should be fine. I'll glue the foam board to the furring strips, and probably glue the 5/16 to the foam board. Haven't decided just yet. I'll see how it looks when it starts going together. 

I assume your spraying from the outside in so you don't end up with a moisture problem in the hollow space?

[Lip_Ripper Guy]

There shouldn't be any hollow space. The spray foam fills the wall cavity, and goes over the metal studs to be flat with the top of the furring strips. The board foam goes over the top of that. 

[YettiStyle]

If you plan on using it as a utility trailer I would recommend NOT getting a Yetti.  Don't get me wrong, I finished off an 8x16' Yetti this year and love it.  Wouldn't get anything but a Yetti for my needs.  The reason you wouldn't be a fan of Yetti is their axle weight limits.  For an 8x16', their axles are only rated for 4,500 lbs.  Now it really depends on how much you add to the inside but after finishing mine out it weighs 4,200lbs loaded and ready to fish - that doesn't include the weight of any of my portable gear though like rods, bait, grill, food cooler, beer cooler (yes two separate coolers, we drink like fish), and auger.  Mine is pretty decked out on the inside but you might be more interested to going with a ridgeline or firebrand just for the increased weight limits. 

Edited March 14, 2016 by YettiStyle