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General => Owner-Builder Projects => Topic started by: ovidgsd on August 29, 2010, 05:29:44 PM

Title: 16x16 camp plans
Post by: ovidgsd on August 29, 2010, 05:29:44 PM
(moved and re-posted - I think I originally posted in the wrong forum tread)
This is my plan to build a single story, single room 16x16 camp in the deep freeze of north Maine in clay soil.  Building will be heated by wood stove with no traditional plumbing and most of the time will be unheated.  This is just the framing and foundation plan.

Foundation: 9 concrete piers at 4 feet deep and 12 diameter, using those big foot forms you can buy at Homedepot at the bottom and insulating around the piers with the guidlines in the frost protected shallow foundation guide - 12" gravel under 2-3 appropriate foam.  Piers are at the four corners, then every 8 feet around the perimeter and one in the middle of the floor - picture 3 lines of 3 - all spans for girders will be less than 8 feet.  Each pier sticks out of the soil by 6".  On top of each pier is 12" of pressure treat 12x12 post.  In galvanized metal in cement anchor for each post (type sold for decks at the homedepot).

P----<8'----P----<8'-----P
/               /                 /
/               /                 /
<8'             <8'             <8'
/               /                 /
/               /                 /
P----<8'----P----<8'-----P
/               /                 /
/               /                 /
<8'             <8'             <8'
/               /                 /
/               /                 /
P----<8'----P----<8'-----P

Girders:  On top of the 9 posts, a box of girders made of 2x12 pine 3 pieces thick (a 3 piece built up girder) that are the full 16 feet.  Then one up the middle that is also 2x12 pine 3 piece built up girder.  Result is two interior boxes of less than 16x8 feet for the floor joists to run across the 8' span of the girders.

Floor joists: using 2x10 pine spaced at every 12" on center - 16 feet pieces.  With the girders in mind, the span is less than 8 feet.  Will do 2x10 blocking every 12" between joists.

Subfloor: 3/4 inch OSB.

Walls:  2x6 walls spaced at every 12" on center.  The walls will use 12' foot high pieces - explaining the extra lumber used.  No need to discuss windows I think - I do have plan and know my header rules. Onedoor. Will do a double plate at floor and ceiling.  I'll build the walls in 8 foot sections to ease building it alone.

Roof:  Premade scissor roof trusses with 10/12 pitch.   Should make for a nice small loft inside. Plan on renting a one-man lift for installing those.  9 trusses with gable ends and 2 foot spacing.

I need suggestions on type of exterior sheathing.  I think the Truss instructions dictate the roof sheathing requirements.

Sticking to the framing and foundation issues only,  your thoughts and comments greatly appreciated! :)  d* ;D
Title: Re: 16x16 camp plans
Post by: Bob S. on August 29, 2010, 06:19:31 PM
Have you looked into parallel scissor trusses? It would make the loft biger and not cost that much more.
Title: Re: 16x16 camp plans
Post by: ovidgsd on August 29, 2010, 08:20:20 PM
Parallel ! Scissor trusts... wow, that is one that I don't know, but I will check it out :) Thanks  Bob!
Title: Re: 16x16 camp plans
Post by: MountainDon on August 29, 2010, 08:40:22 PM
 w*   ovidgsd     It would appear you might be over designing the foundation/girders, joists and walls. Nothing wrong with over designing or over building; it is preferable to under designing and placing your fate in the hands of 'good luck'.   :D

Piers/posts: a PT 6x6 on the concrete pier will support your load with no problem at all.

NOTE: Some of the below may depend on whether or not your soil can support your structure on just 6 piers. In some places more piers would be required to ensure their ability to carry the weight of the structure and contents.

Girders: With beams being built up from three layers of 2x12's you can dispense with the center beam. One of those triple laminate 2x12 down each side would work with a pier spacing of around 7 feet. A slight overhang at each end coupled with the 12 inch diameter concrete piers makes that easy to achieve.  The girders can be built from shorter lengths as long as the joints are over a pier.

The girders do not need to have the ends 'boxed'. However, the joists that sit on the girders would have rim joists nailed to the ends of the joists to create a joist 'box'.

On a building with trusses or rafters and a gable roof the building weight is carried by the sidewalls (parallel to the roof ridge) and the end gable walls simply support themselves. Usually the center beam can be eliminated in a structure under 20 feet wide, as long as the joists are sized correctly and the two girders are adequately supported.


Joists: Southern yellow pine, 2x10, grade #2 can span the full 16 foot width without a center beam; 16 " OC, 40# live load, 10 lbs dead load; even good for ceramic tile. Twelve inches OC would be stiffer, but not really needed unless you wanted it. See note below on insulation.

I'm not clear on what you mean by  "Will do 2x10 blocking every 12" between joists."   A row of solid blocking down the center, parallel to the beams/girders.  would be sufficient. With a center beam it is mandatory (IRC).


Walls: According to the IRC 16" centers with 2x6's is all that's required, even 12 foot tall. Twelve inch spacing will make it more difficult to insulate with products such as precut batts. Twelve inch centers also reduces the effective R-value as there are more studs per wall length and studs are less efficient insulators.    Winds over 100 mph or a location subject to special seismic loads may require following some special rules.

A double plate at the floor in unnecessary unless you have some special requirement because of some special thick flooring or something else unusual. Double upper plates make it easier to tie the wall corners together and allow for more versatility in rafter or truss spacing.


Question regarding the loft:  Are you planning the loft floor to be at the 12 foot wall height level?


Exterior wall sheathing: The structural layer could be OSB or plywood, 7/16" or 1/2" or thicker.  Then the weather resistant layer (building felt or house wrap) and then the cosmetic layer (lap siding, panels, stucco, etc.)


Title: Re: 16x16 camp plans
Post by: ovidgsd on August 30, 2010, 10:03:19 AM
Don,

Thanks so much for your time and comments - priceless.  I do like to over build but I think I'll have to do the walls 16" on center as you mentioned b/c I really should have good insulation at my location.  Same with the floor joists.  I have a framing book that recommends the same, but I did not consider the detriment to the insulation.

My loft will be very small (thinking 8 x 6) but will rest on the wall 10 feet, so I'll use extra studs there.

I was clearly thinking of way to much blocking in the floor joists ;) thx

Now time to grade the site and dig the holes......... hope it does not rain much on me this weekend, or that will have to be delayed. :(
Title: Re: 16x16 camp plans
Post by: ovidgsd on September 22, 2010, 07:51:17 PM
The build is underway!

6 concrete piers 5 feet deep with 28" square feet - a little over kill per the general contractor that helped me out with his excevator - but no problems (two rows of 3 along the roof line).  2x12 girders at 3 thick all around sitting on 2 - 6" high 6x6 posts.

        Lesson's learned - 1) a mini excevator just can't dig the needed foundation in super rocky, dry, clay soil.
2) back filling with a skid steer in muddy clay soil conditions is POINTLESS
3) cement truck delivered cement is a wonderful thing!!!!
4) don't drive a skid steer near your building (yes, you guessed it -  :(  )
5) make friends with good local people near your build that have experience to share and have the resources to help you when you screw up! because you will!

Time to build the floor and insulate it!  will use 2x10's at 16" o/c - hoping to do the floor, enterance stairs, insulation under floor and subfloor next weekend.

Build build build :)  d*