12x16 Mt Hood "Workshop Chalet"

DirtyLittleSecret · February 19, 2009, 12:04:20 AM

Greetings to forum members! First off, I've browsed and searched through the site, and am amazed at how much material is available...thanks to its community & members. This really is an asset.

My wife and I are about to begin an adventure by building a sub 200 sq ft "cabin" (12'x16') on our 2 acre lot up on Mt Hood (~3,000 ft elevation). It's been in my name longer than I've been alive, but even though I'm "grand father'd" we don't want to face all the permitting requirements, as we would like to build a larger residence later sometime, and while I've worked as a mechanic and welder, I have little experience in homebuilding besides some projects. Had plans to start last Summer, but the place needed to be cleaned up which took a good deal of time (okay...A LOT of time). Finally graduating after 12 years of University, and sprinting into the career marathon had some leverage on my spare time as well... Already have most the tools including saws, ladders, welders, generator, air compressors, common sense, etc.

Anyhow, we plan to use our "Big Enchilada" kit, and the 12'x18' plans. I swung by the county planning department to inquire about building a sub 200 sq ft "utility" building. Already figure'd out where to place the building, but still have about 2' of snow on the ground. Will be shooting for something like Bishopknight did with his cabin: http://countryplans.com/smf/index.php?topic=4569.0.

According to the Planning Department, my frost depth is 24", and the required snow load is 150 lbs with wind rating requirements at 94.5 mph gust. I am assuming that I will need to upgrade my materials to 2"x6" instead of 2"x4", and follow the "sonotube" or "cold climate" footings as per: http://countryplans.com/foundation/index.html. I am still considering whether it would be best to add a third row of footings for additional footing, and offset/increase the footings to nine (9) instead of six (6).

Also have to figure out how to meet the State of Oregon requirement that the middle/midline of the roof (between the crown and eaves) must be 10' from the bottom of the "finished floor"/bottom of structure. All three (3) planners had different definitions on this one, but I want to make certain that I'm staying kosher. Plan to use metal roofing, and figure that this will allow me to adjust angles/extend eves if necessary.

Any ideas, recommendations, or additional insight would be much appreciated! Thanking you all in advance!

Property Shots:

glenn kangiser · February 19, 2009, 12:32:43 AM

Let us know what you find out about that rule - it doesn't seem easy to understand - does that mean a low pitch roof - in a high snow load area?

I am originally from Lincoln City.

February 19, 2009, 12:46:10 AM

Yeah, all I could understand was that regardless of <200 sq ft, the mid line of the roof (from crown to eaves) could not be more than 10 ft from the finished floor. Nowhere in any of the county handouts (nor OAR's) could I find anything regarding this, but got numerous answers from the planning department from "finished floor", "ground", and "bottom of structure not including pillars".

MountainDon · February 19, 2009, 01:33:12 AM

That's a hard one to understand.

Are they really meaning that the 10 foot distance is a maximum distance from the floor to the roof, and not a minimum distance, or even an exact measurement. I could maybe understand if it was a minimum distance, and that would be easy to meet.

If it's a maximum that seems nuts; it would totally make it impossible to make a 10 ft high interior ceiling height for example. Plus it seems screwy in light of the need to build to 150 lb snow figures. Steep would be a good roof for those conditions.

Best of luck on sorting that out and I'm really interested in knowing the answer.

Don't ya just love red tape?

MountainDon · February 19, 2009, 01:41:51 AM

... and you have nice trees.

February 19, 2009, 07:33:29 PM

Beautiful lot . . .

DirtyLittleSecret · February 19, 2009, 08:50:39 PM

Thanks guys. Got alot to figure out, and am waiting for the snow to recede.

Any guidance as to my foundation post quandry? Was planning on doing another row of posts (9 instead of 6), but I dont want to just waste money. With a frost line depth of 24", I was going to go 36" with the 10" sonotubes, and then do the 6"x6" PTW posts to the crossbeams using Simpson brackets to "adjust height as necessary".

Am I on the right page with this reasoning, or is it advisable to simply level out the concrete posts directly to the crossbeams? It would be nice to allow some adjustability in case of settling...

diyfrank · February 19, 2009, 10:43:21 PM

Are you saying, put a short post between a sono tube and beam?

I think you would loose some strenght. Having it like that sound like a place to flex. Putting the beam directly on your sono tubes would be more secure. you could still use an adjustable connector if you think theres a need.

MountainDon · February 19, 2009, 10:47:01 PM

Number One; correctly done footings will not require adjustments. Leveling the tops of the poured concrete can be done if you take your time and properly brace the sonotubes so they do not move when you pour and tamp the concrete.

The number of footings and piers/posts required depends on the ability of the ground to bear the loads and the size of the beams being placed on the piers/posts. If your soil is average the way John has drawn the plans will be sufficient, depending on approval from the local permit department.

Footings 36 " deep should work fine.

February 19, 2009, 11:32:32 PM

Glad I asked. I was already reconsidering that idea as it seemed somewhat counterintuitive, and began wondering why I couldnt just go straight to the concrete posts (plan to use 10" sonotubes, and make due with eight (

footings on two crossbeams). Just more concerned with the snow loads, etc. Any better ideas?

DirtyLittleSecret · February 20, 2009, 11:27:56 PM

Almost forgot...what am I looking at to meet the 150 lb snow load requirement? I'm assuming something more than 2x4 framing and perhaps more than 2x8 crossbeams, etc...Planning on 2x6 framing, but am unsure regarding the 2x8 crossbeams and rafters.

glenn kangiser · February 20, 2009, 11:43:36 PM

I'm going to guess that that loading will require and answer from a local pro - not sure if anyone here has had to deal with that.

Also the funny requirements there as to roof height may make that mandatory. A truss company may be the cheapest way to get that accomplished.

MountainDon · February 21, 2009, 01:08:00 AM

The AWC calculator...

http://www.awc.org/calculators/span/reversecalc/reversecalc.asp
or
http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

... indicates that for a gable roof, 12 foot wall to wall distance, 6 foot horizontal rafter span, 16" OC rafter spacing, deflection L/240, snow load 150 PSF, 10 LSF dead load....

S-P-F #2, 2x6 lumber will meet the specs. 2x6 is at the limit though, so 2x8 would provide a measure of security. 2x6 at 12" OC would also be better but not as good as 2x8 at 16" OC.

You still need to clear up that 10 foot number to see just what it is they mean.

DirtyLittleSecret · February 21, 2009, 01:32:46 AM

As the county planner described it on a napkin (I'm not joking):

What's funny, is that NONE of the public material mentions the 10' rule, and I searched the Oregon Code to no avail...I'm going to have to reconfim this with upper management who might be able to describe it on tissue paper for a more formal description.

Thanks for the great tool (AWC calculator)! I saw where it was referenced in a thread, but didnt see it linked.
Will have to think about the 2x6 vs 2x8 issue. 2x8 will eat up ALOT of space, and a metal roof it might help with the load as well. Any additional thoughts would be much appreciated.

Had'nt thought of a truss company, but its something I'll definitely look into it...as always it depends on costs! I do have access to a 5 ton military wrecker (crane) for mounting trusses if needed...did some backyard gardening last year with it.

February 21, 2009, 10:42:11 AM

With it being stated that it's a minimum of 10 feet, that should be workable without too much bother.

DirtyLittleSecret · February 23, 2009, 11:45:12 PM

Okay. Got clarification from 5 county planners today as I was driving back from Olympia.
The 10 foot "rule" states that the maximum distance from the "finished floor" (where one stands) and the "median height" of the roof...
So my concerns are a little alleviated, but will probably be forced to use 7' walls and low eaves to meet this requirement.
Any other ideas would be much appreciated.

Jens · February 24, 2009, 12:43:51 AM

11' on one side, 9 on the other, living roof with 2x12 rafters 12" on center. Build a loft that floats in the middle (doesn't touch the walls) so that the bottom space gets nice light. Those are my ideas anyway

DirtyLittleSecret · February 24, 2009, 01:11:28 AM

Quote from: Jens on February 24, 2009, 12:43:51 AM
11' on one side, 9 on the other, living roof with 2x12 rafters 12" on center. Build a loft that floats in the middle (doesn't touch the walls) so that the bottom space gets nice light. Those are my ideas anyway

Could you elaborate? Kinda lost me with the 11/9 thing...and 12" rafters?

MountainDon · February 24, 2009, 01:27:31 AM

Quote from: DirtyLittleSecret on February 23, 2009, 11:45:12 PM
Okay. Got clarification from 5 county planners today as I was driving back from Olympia.
The 10 foot "rule" states that the maximum distance from the "finished floor" (where one stands) and the "median height" of the roof...
So my concerns are a little alleviated, but will probably be forced to use 7' walls and low eaves to meet this requirement.
Any other ideas would be much appreciated.

That's a stupid rule!
There I feel better.

I really do have trouble understanding why it's a maximum distance?

Seven foot ceiling height is going to feel cramped, IMO. BTW, that is the bare minimum code height for finished floor to lowest projection from the ceiling. Sort of precludes the use of any ceiling fans and limits ceiling light fixtures too.

That 10 foot distance would also mean nobody could build a room with a ten foot ceiling height and that is a commonplace feature in many upper scale homes I've seen.

You have all my sympathies in dealing with that rule.

You can access online versions of the Oregon 2008 code (no print, no save) HERE.

Jens · February 25, 2009, 10:10:39 AM

Sorry bout that. Shed roof, one wall is 11', the opposite wall is 9'. Run 2x12 rafters, 12 or 16" on center, gives good support for a living roof, especially one with snow on it. BTW, I can't remember how much snow is common up there. Snow held onto the living roof, will actually increase the R value of the roof. Run a few ceiling joists at the loft height, probably 7' or so, and have the loft itself just sit in the center of the room, not touching the walls...just a thought. Or it could be a twin bed deep loft along the high side, more of a bunk. Then again, set a queen sized loft at one end, at 5-6', and have closet and seating underneath. IDK, just thoughts.

See the shed roofed idea here http://www.jshow.com/y2k/listings/29.html

February 26, 2009, 12:46:35 AM

Quote from: Jens on February 25, 2009, 10:10:39 AM
Sorry bout that. Shed roof, one wall is 11', the opposite wall is 9'. Run 2x12 rafters, 12 or 16" on center, gives good support for a living roof, especially one with snow on it. BTW, I can't remember how much snow is common up there. Snow held onto the living roof, will actually increase the R value of the roof. Run a few ceiling joists at the loft height, probably 7' or so, and have the loft itself just sit in the center of the room, not touching the walls...just a thought. Or it could be a twin bed deep loft along the high side, more of a bunk. Then again, set a queen sized loft at one end, at 5-6', and have closet and seating underneath. IDK, just thoughts.

See the shed roofed idea here http://www.jshow.com/y2k/listings/29.html

Got it now. Very good idea going with the shed roof, but I think my wife would kill me with the snowload being so high (150 lb). My original idea was to simply do a steep pitch and simply lower the eaves (say 2-2.5" eaves) to MAKE it fit the 10' maximum requirement. This would effectively lower the "center/middle" of the roofline while allowing for a fair loft.

Jens · February 26, 2009, 05:09:55 PM

you could put half of the house underground, put in a false floor, get it checked off, then remove the floor!

Jens · February 26, 2009, 05:11:21 PM

BTW, I can't imagine the described roof not taking that snow load. Not saying you or your wife want it, just that it shouldn't be a problem. Here is the chance for an engineer to chime in

MountainDon · February 26, 2009, 06:32:01 PM

The AWC calculator comes up with 2x12 of most commonly species being okay 12" OC with 150 lbs snow load, 15 lb dead load, L/240, in #2 or better. 12 foot span was used.

MountainDon · February 26, 2009, 07:25:52 PM

I was curious, to say the leastm about what that 10 foot rulw would mean for a 12 foot wide cabin. So I drew it out on paper. I show three different pitches, 4:12. 10:12, 10:12. I don't like the 12:12 as the extra overhang needed to meet that 10 foot rule drops the eves down too low, IMO. It gets in the way of the windows. It would appear the 10:12 would work.

Do FWIW, there it is.