Another under 200sf cabin

[John Raabe]

Today I visited a property where the owner had put up a nice small cabin to stay under the 200 sf permit triggering level. He actually used the roof area as the determining factor so it is a bit smaller - at about 9'x18' - than would be required in most areas where area is measured to the outside of the walls.  (It could be 11'x18').

This was put up on the Little House post and pier foundation with cement board skirting. The owner used just 3/8" thick T1-11 blanks for sheating and siding and put it up with minimal framing using recycled windows and doors.

You could use the 12x18 Little House plans here: http://www.jshow.com/y2k/listings/29.html - and then adjust to fit your materials.



It is pretty unassuming and shed like on the front, but really opens up to the woods behind on the inside.



Not a bad place for storing things or spending a night or two in "upgraded camping".

PS - As I look at this a bit more closely, the builder has used OVE - "optimum value engineering" techniques where you align the rafters and the studs and eliminate one of the top plates. Very sophisticated!  

[DavidLeBlanc]

The loft beam looks like serious overkill?

Is that a ridge beam I see at the top of the rafters?

[JRR]

That beam may actually be more "bed rail" than "beam".   Quite possible there's a set of springs under the mattress.

[John Raabe]

Actually that loft is quite elegant, in my opinion.

The beam is a rough 2x12 that is screwed into the studs on either side and serves both as the support beam and as the bed rail. Underneath and on the backside is a ledger that supports the flat 2x4 slats under the sheathing (I might have sacrificed a bit of headroom and turned those 2x's 90º). This all supports the mattress and springs.

I like the window there right at bed level - nice thing to wake up to  .

Did you notice also the way the window header on the left is supported by a less than full length cripple stud? Good use of material at hand and a few extra nails will handle the shear. Practical OVE engineering (by the seat of the pants!)

The ridge board is an old tough 2x with the rafter tails strapped to the top plate. Plenty strong!

[DavidLeBlanc]

Didn't mean to imply that the loft wasn't nice looking, just that the beam looked like far more than what's needed (except for the added purpose of making sure the mattress wasn't going to slide off the loft).

"Window on the left cripple" - do you mean the board on the right edge of the window that stops a few inches below the window ledge?

Are the walls 2x6" oc?

What's really scary is that I can almost see myself living in something that small - and liking it!

I NEED LAND!

[Amanda_931]

I do know at least one person who built a place about that small on "not his land."

He was working on the property owner's house way out in the country, and it was a lot more convenient to get something up so he could live on site.

It worked for well over a year.

[DavidLeBlanc]

Any ballpark estimate of what this tiny house would cost to build?

[John Raabe]

About $2,000. With used widows and doors. Metal roof if I remember right.

[Mike Teskey]

As a visual learner, I appreciate seeing the images of this cabin, especially the interior shots with the ensuing discussion.  Here is my question:

In terms of building the roof, is it acceptable to build the loft first, then frame the roof?  If so, then I can more easily see how I will safely do part of the rood myself.

mt

[John Raabe]

Yes, as long as you have tied all the four perimeter walls together with a double top plate or steel splice plates you could build the loft first and frame the roof from that platform.

[Lady_Novice]

As I've been debating trusses versus rafters, I'd love to figure out his roof. It looks simpler and easier than a typical rafter roof, but I hope my questions make sense?

It seems he did rafters with an exterior overhang yet without laborious birdsmouth cutting? The ends of the rafters seem to rest on angled top plates at the sides in the interior. Given their angles, I can't tell how the top plates manage to rest securely on the studs?

Since the rafters are within the interior, how did he get the exterior overhang? Maybe by just extending the sheathing outward, which is something I've thought of, but I don't know if plywood sheathing (without purlins or something) can take the strain of typical snow loads?

Did he not need collar ties? Perhaps the span was short enough not to require them, or enough rigidity was supplied by the Simpson-type connectors and the ridge board (guessing)?

Thanks for any info,
LN

[John Raabe]

Yes, in this little building the rafters are not notched. They are attached to the top plate with framing anchors. The builder has also used OVE (optimum value engineering) practices by lining the studs and rafters on the same layout (24" o/c) and using only a single top plate (spliced with a metal plate at the joints).

The top of the rafter pushes from both sides against the ridge board and no collar tie is needed for this span. All this is transfered into the wall with the framing anchor!

The 2x12 tie of the loft also helps to tie the walls together and resist the outward forces of the roof.

A minimalist effort that is more sophisticated than it might appear at first.

The rafters just extend out past the wall and carry the desired overhang with the same roof sheathing as the rest of the roof.

[hobbiest]

It seems he did rafters with an exterior overhang yet without laborious birdsmouth cutting?

there are rafter ties available that are diamond shaped, and connect to both sides of the rafter, in some photos from the company, I have seen them used in such a way.

The ends of the rafters seem to rest on angled top plates at the sides in the interior. Given their angles, I can't tell how the top plates manage to rest securely on the studs?

Not quite sure which ones you are meaning.  The bottom of the rafters are on the plates, which are level with the ground, and there are blocks in between the rafters, installed square to the rafter.  Normally, the birdsmouth, or seat cut, would bear squarely on the plate, and the blocks between would be far enough out so that there inside edge contacts the top of the wall.  Hope I cleared some stuff up, and didn't just confuse further.

Since the rafters are within the interior, how did he get the exterior overhang?

The rafters extend beyond the walls.

Maybe by just extending the sheathing outward, which is something I've thought of, but I don't know if plywood sheathing (without purlins or something) can take the strain of typical snow loads?

Definately would not use unsupported overhangs.

[jraabe]

Please be aware of the scale involved in this little building. Don't assume you can get away with these minimalist techniques in a larger building with wider spans and heavy roof loads.

Plans such as the Little House kit show much more conservative and standard construction techniques for building small houses. They are, for most people and most buildings, a better way to build.

I don't want people to see this analysis as promoting such construction shortcuts. This caveat is especially true for new builders who may not fully understand what they can and cannot get away with.

Remember it is always the cobbler's kids who have the rattiest shoes. Only he knows exactly how long he can go before he really has to fix them.  

[Lady_Novice]

Thanks to John and Hobbiest for your answers to my questions.

Sorry that a couple of my questions were based on an optical illusion perhaps due to shadows or whatever, i.e., the rafters appeared different on my screen than in real life. As y'all point out, in real life, the rafters extend beyond the inside of the cabin, the top plate is not angled, and so on. So it would seem the rafters are fairly standard except that the builder uses the anchors rather than birdsmouths. And now I see it makes sense that the loft (similar to the bottom of a truss) helps prevent the outward thrust of the roof.
LN