Will this work?

[PHU]

Just recently joined this site....and I must said...AWESOME site with incredible wealth of knowledge and information for the DIY. 

So as such....I've been designing beam ideas and this is what I have come up with so far.  Please view the attached drawings and give me your inputs? 

Short introduction....I'm in the process of "GATHERING" ideas/information as to how to build a cabin....so more questions will be posted for sure as I break ground next year early Spring, I hope.  I'm thinking of building a 16x24 size cabin.  Can this be accomplished with just 10K as budget?  No fancy log siding or modern conveniences other than just the "essentials". 

Thanks you for your time.

Jim

[rick91351]

For 10K logic tells me no.....  But really I would think if you are a careful shopper.  Live on Craigslist, and the other places that you can make a deal, it would sure be fun to try.  That said doing it yourself you would or should be able to save additional couple K while you are building.  Hate to tell you this but it does not happen over night or over a couple weeks.  How far is drive and is that worth it?  Inspections and building permit required?  Power and water in or?     

[Don_P]

That is one way to build up a beam, whether it is correctly sized depends on the load, species and grade. That is a very poor way to create a foundation. If the posts extend from the top plate of the walls down to the foundation they are then braced by the wall sheathing, the floor beams are then hung on the posts or supported on blocks that run from foundation to the underside of the beams.

[PHU]

For 10K logic tells me no.....  But really I would think if you are a careful shopper.  Live on Craigslist, and the other places that you can make a deal, it would sure be fun to try.  That said doing it yourself you would or should be able to save additional couple K while you are building.  Hate to tell you this but it does not happen over night or over a couple weeks.  How far is drive and is that worth it?  Inspections and building permit required?  Power and water in or?     

I realized my budget is a wishful thinking only.....how many owner's builder has changed their mind along the building process, whether a design change or material upgrades?  So the 10k is just a rough number to keep me on a budget conscious without going overboard other than just the "ESSENTIALS".     

Maybe go smaller 14x20? 

That is one way to build up a beam, whether it is correctly sized depends on the load, species and grade. That is a very poor way to create a foundation. If the posts extend from the top plate of the walls down to the foundation they are then braced by the wall sheathing, the floor beams are then hung on the posts or supported on blocks that run from foundation to the underside of the beams.

Hi Don...

As far as the foundation is concerned....no definite decision has been committed yet.  I'm still undecided at this point as whether to go with a post and beam, concrete piers, or concrete perimeter footing.  If post and beam is chosen.... The posts will be buried below frost line and protrude above grade at least 18" with supporting braces.   

Do you think i need a center support beam since I'm going to use 2x8 joist @ 16" on center? Too weak?

Thoughts?



Thanks,

Jim

[Mike 870]

Yea I would go with a center beam, I spanned my floor with 2 by 8s on a 16 inch center, the span was only about 11'4" and it was too squishy for my taste.  I'd also move your beams out all the way to the edge.  And don't cantilever on the gable ends either.

[PHU]

Yea I would go with a center beam, I spanned my floor with 2 by 8s on a 16 inch center, the span was only about 11'4" and it was too squishy for my taste. I'd also move your beams out all the way to the edge.  And don't cantilever on the gable ends either.

Thanks, Mike.  I have the same thought, but wasn't sure.  I guess....having it overbuilt is better than under.

Hmm....reasons behind that last comment in BOLD?

[MountainDon]

So ... ....I've been designing beam ideas and this is what I have come up with so far.  Please view the attached drawings and give me your inputs? 

At this point is there a definite plan as for how much building is go on this proposed foundation? One story, 1 1/2, 2 loft, no loft? Will there be any unusually heavy items placed inside? Water bed, large gun safe, water tank, ... ?? Those details influence the foundation. It may seem backwards but the foundation should be designed last, even though it is built first.

In addition to the above, in order to help best it is necessary to know the rough geographic area where the project is located; snow and wind loads have to be considered as well as seismic.

~~~~~

Don_P and Rick touched on these next 2 comments. Don commented on Ppiers and beams; pier and beam is used by many builders as you have likely seen; one reason is because it seems inexpensive at first glance. Sometimes they work and sometimes they do not. In many places it does not cost much more to build a better foundation.

Rick asked about building permits and inspections. Part of his reason for asking that was likely because in any area where there is code enforcement being done according to the book, the IRC code book, a pier foundation will be rejected if the authorities are doing their job by the book.

Piers are not mentioned in the code (IRC). The IRC is a prescriptive code; it shows what types of things are permitted without any input from an engineer. It is possible an engineer might approve a pier foundation in the manner most are built. But he has to be paid to find out yes or no. The reason piers are in this limbo area is that soils vary a lot. Some might be suitable, many are not. Soils also change with moisture content. So there is no guaranteed safe general method for using piers and beams as you have illustrated. They are used, just remember they are not on an approved for all situations/locations, and for good reasons.

Even if codes are not being enforced where your project is located many of us believe there are many good reasons to follow them.

~~~~~

Re the 2x8 floor joists. Spans depend on species and load as well as size and span distance. There are tables in the IRC. (We have an IRC reference section. ) There is also an online rafter and joist span calculator available from the AWC.

2x10 DougFir #2 could span 15'7" maximum, sorta just barely according to the AWC calculator. That might be okay if this is a cabin with lighter floor loads than what many typical homes need to contend with. Might be easier than a center beam and more foundation.

~~~~
Cantilever: A floor joist cantilever distance equal to no more than the depth of the floor joist is permitted by code. Any greater amount must be engineered to meet code.

G/L

[Squirl]

The beams for the foundation are also known as girders.  In framing they function almost the same way as a header.  They take an evenly distributed load and displace it over a greater distance to points.
Luckily, the building code has all this built in with charts on what sizes all the lumber should be.  It's all free online too.

Because the charts may be confusing to someone unfamiliar, I did a post to help people read them.
http://countryplans.com/smf/index.php?topic=10511.0
As you can see from the charts, what will be above and snow loads will heavily affect it.  Location is important.  A few weeks ago, someone from Florida was looking to build a pier foundation.  Florida and California have some of the strictest building codes in the country because of the severe weather.  I have never seen a foundation like that approved in that state.

I am not as critical about pier foundations for tiny cabins.  It is when they get very large that the loads can really multiply and I personally believe they are less safe.  Post and pier makes less sense the further south you go.  With less frost line, a concrete, block, or slab foundation can be the same price and is twice as stable and longer lasting.

10K is a little too low in my opinion.  There are many fixed costs that are regardless of size.  Bathroom, Water heater, septic, electric, water well.  I could build a box for 10K, but with nothing in it.  I guess it depends on what you call essential.  Drywall?  Insulation?  A roof?

[PHU]

Hey guys...Just an udpdate......I hope everyone is doing well.....I've been busy designing and planning the cabin.  Spring is just not coming any faster! lol.  I'm building this cabin in my head already....perhaps the most taunting task is laying out the foundation and making sure everything is SQUARE before the framing starts. 

Attached below are a few pictures showing where I'm currently at with design.


Some questions....

1.  Picture #1

How do you flash the porch to the wall?





2. Picture #2

What are some designs/layouts that maximize the loft area?  What show in the drawing is a simple design I've seen being done.




3.  Picture #3

What are some inexpensive materials to use for the bottom 1/3 of the walls? 

  I was thinking of using metal roofing to cover the bottom portion? Thoughts?






And lastly,  please give me your inputs on the general overall of the design? What could be done better? Basically, anything you can advise to make the cabin look better.  With this being said....I do need some iterior layout ideas. 

Thanks folks!

Jim

[MountainDon]

1.  Flashing is more difficult to do when the structure has only a single layer of siding like the T1-11 as shown. When there is a "sub" sheathing such as OSB, then house wrap or building felt, followed by a final finish siding it is much easier.

You would have the flashing under the building paper/felt on the wall and over the metal roofing so water would always be led to the outside of the wall/roof. No dependence on caulk as the main or only barrier to water.

Using sheathing first also gives you the opportunity to use 9, 10 or 12 foot osb panels vertically and tie the rim joists to the top plate together for maximum strength.


2.  The loft joists as drawn is a poor design. Doing it that way places extraordinary high loads on those joists/beams that the short loft joists connect to. The loft floor joists should cross the width of the building from one long wall to the other. That way they also connect one long wall to the other. The cat walk can be then hung of doubled joists or a beam depending on loads, spans, etc.


3.  The entire wall can then be lap sided top to bottom. Transition from one type upper to another lower can be done but watch the water flow... lead to the outside, out and over.

[PHU]

1.  Flashing is more difficult to do when the structure has only a single layer of siding like the T1-11 as shown. When there is a "sub" sheathing such as OSB, then house wrap or building felt, followed by a final finish siding it is much easier.

You would have the flashing under the building paper/felt on the wall and over the metal roofing so water would always be led to the outside of the wall/roof. No dependence on caulk as the main or only barrier to water.

Using sheathing first also gives you the opportunity to use 9, 10 or 12 foot osb panels vertically and tie the rim joists to the top plate together for maximum strength.


2.  The loft joists as drawn is a poor design. Doing it that way places extraordinary high loads on those joists/beams that the short loft joists connect to. The loft floor joists should cross the width of the building from one long wall to the other. That way they also connect one long wall to the other. The cat walk can be then hung of doubled joists or a beam depending on loads, spans, etc.


3.  The entire wall can then be lap sided top to bottom. Transition from one type upper to another lower can be done but watch the water flow... lead to the outside, out and over.

On #2....is this what you're referring to?  Just want to make sure I understand.

Thanks

Jim

[MountainDon]

Yes.  It is still not according to code because of the short walls extending up from the loft floors. That leaves the wall tops where the rafters meet the top plates without any actual rafter ties. According to code the rafter ties must be at or above the wall tops but not higher than 1/3 the way up the rafter triangle. This technique is seen often, but no matter how many times it appears a code official would not accept it if he/she was reading the book correctly.

The area of the catwalk is also without rafter ties. Nothing in that area to restrain the walls from outward rafter push.



It would be better strengthwise, to make the lower walls only 8 feet tall. Build the loft floors as a normal second floor. Then short walls, 4 to 5 feet tall with rafters and rafter ties raised to the 1/3 mark up from the plate. Make the short side walls as high as they would need to be to provide headroom from the loft floor to the raised rafter tie.

A second approach would be to include a structural ridge beam with column supports at the gables and maybe an intermediate point. Those would go down to solid foundation. Then there would be no rafter tail push out as the beam  / columns carry the roof load. Properly sized and supported that would meet codes as be solid.

[Don_P]

There's a problem at the catwalk to far loft in the latest version. Run the catwalk all the way to the clear spanning joists.. you have one of those "skyhook needed" situations going on. If that newel post is centerline above the mid girder and under the ridge I would run it down to the floor (with support clear to a footing) and up to the ridge thus breaking a ridgebeam span length.

Is the front girder checked for both house load and porch load? To pick up at least some lateral stability a block wall under that side of the house and rounding the corners at each end 4' or so would help a great deal.

Do notice how tall the chimney will need to be outside to clear the ridge, and if this is snow country it is at the base of the slide.

[PHU]

Hey Don-P...thanks for chiming in....I've done some modifications to the loft design. I hope this new design is a lot stronger than the previous version?


As for your question about the porch, YES...it's attached to the front girder.  I may use metal joist hangers and just run a 2x ledge across the front as additional support? Nonetheless, it's working in progress.

Needless to say.....i did a rough calculation of cost....OMG....things ADD up very quickly.   

Attached are rough drawings of the loft assembly....I hope this will give you an idea where I'm heading. 

Please feel free to comment.



Thanks.

[Don_P]

If you can put a winder or two and a step or two to the landing it'll help the stairs and allow the catwalk edge to centerline. Then those newel posts at each end of the catwalk can run up to the ridge making a ridgebeam up there relatively small and easy to install. As it's drawn there are no thrust resisting ties so the easy way is to hang the roof off a structural ridgebeam. Don't forget to box the risers.

Rather than short piers under the structure, poorly braced in one direction... and unbraced in the other, with unbraced girders sitting on top of those. This is a quick concept sketch of the main members of one way of incorporating the postframe method I was describing earlier. The continuous posts running from footing to top plate on the perimeter are braced by the wall sheathing.

[taiwin]

Looks like my 12x16

[suburbancowboy]

This might help you out visualizing what you are talking about.  I had a similar concept on my 20X36 that I build.  I built this with engineered plans that was to code.  The main beams across the width where three gluelam beams.



I used scissor trusses on the roof.

[suburbancowboy]

This might help you with the stairs.