Author Topic: Peaceful Ambitions - 14 x 24 House  (Read 938 times)

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Offline Peaceful Ambition

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Peaceful Ambitions - 14 x 24 House
« on: March 20, 2017, 01:45:24 AM »
Hey everyone I've been lurking and learning here for a LONG time and I'm very excited to finally be able to contribute a thread of my own!  We're going to be building the 14x24 Little house plan this summer and I'll be posting plenty of pictures and keep you all updated with hope that not only will you enjoy it but that many pairs of eyes checking my work could potentially save me some headaches!

A little background...I live in an area in the west which can get quite snowy, the snowload map for our property says snowloads can reach 40-60lbs ( thats if I'm looking at this snowload map right, It may be less). Wind gusts in the area can reach 75 mph although we have trees on our windward side so I don't know how much we actually get.
I want to build the house as strongly and safely as possible but after checking with the building dept for our original idea of 120 sq feet and after being told that not only was our house idea 'not big enough' but that permits and prerequisites and such could likely exceed the cost of the whole house ($10,000) I can not/will not deal with the permitting process >:( so we figured we might as well go with the bigger option as our area is well out of the way in an unincorporated area of a rural county and no neighbors. It's been our dream to build our own place for a while and I'm extremely glad a resource like this exists online. I am a complete newbie though so please forgive me for asking any rediculous questions. d*

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So here is where I'm at so far:
I am having a contractor/friend do the 16x16x16 footings and getting them square because If I mess up I really don't want to have to dig one of those suckers out.

Walls will be done with 2x6 studs and hopefully 10' tall if I can figure out the loft.

After reading about cantilevers and because the plans extend 2 feet out from the beams (and considering our potential snow load) I am probably going to be changing the joists to either 2x8 or 2x10s at 12'' or 2x12s at 16'' just for the extra peace of mind.
We will be doing a metal 12 in 12 roof so I doubt the snow load will get that high but I'd rather be safe than sorry. What would you suggest?

As previously stated we'll be going with the 14 x 24 little house plans, very inspired by the Nash house
http://www.countryplans.com/nash.html
specifically the amount of headroom in the large sleeping loft. But I'm confused when looking at the pictures of that loft, and comparing them to the plans and what I've read in many other threads on this website.

The plans call for two partial lofts (we'll probably just do the large loft) and a cathedral area in the middle, but from my understanding, unless you are tieing the walls together with a full length loft, rafter ties are required for the entire length of the house due to roof thrust.
It seems like in the LH plans the loft joists ARE the rafter ties. If this is so, how is the nash house able to safely use 10' walls with only collar ties over the open area? ??? Do the little house plans do this as well? I can't tell because the diagrams only show the rafters from the ends/corners.

I also notice the nash house has a beam right in the middle of the large loft to help support it, is this required or just there for some extra support? Does the beam go through the floor into a footing or is it just tied into the floor joists?

I realize thinking about the roof before I even have the walls up may be putting the cart before the horse but I really want to have a clear mental picture of what we'll be doing before I start.

We're waiting just a few more weeks for the rest of the mud on the road to dry before the footings will be done but I will post some pictures of the site soon!
Thanks for reading this far. See ya soon
« Last Edit: March 20, 2017, 02:10:18 AM by Peaceful Ambition »
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Offline Don_P

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #1 on: March 20, 2017, 08:39:20 AM »
 w*
Headache #1, well, I can be polite or I can be honest. I'll be honest but it is not with the intent of being impolite. When you choose to build illegally, don't spend more than you can lose. You inquired about a 120 sf house and plan on a 336 sf house, it may pass. If the house is "caught"... and I'm not sure how people expect to hide an elephant in their yard for a lifetime, the inspector will probably want to inspect it and anything not built right will need to be brought up to code, or he can simply have it removed and send you a bill for that. When I say "code" generally what I'm really talking about is rational design based on physics and experience. I'm not enforcement and don't have a dog in it, just seen people do it to themselves before. I've also seen contractors get caught in the middle of a situation like this, lose their license and their "friend" leaves them flapping in the wind. Not too long ago a friend of mine was busted, the homeowner had talked him into working on an unpermitted house. Another contractor that had bid the work turned them in. That guy is a jerk and there is a good old fashioned case of karma coming down on him but he was not wrong either, you never know where it is going to come from. There is an old saying "a wise man learns from the mistakes of others, a fool from his own". I don't think that needs further discussion, your call on how you proceed.

Actually most people put the cart before the horse by not looking at the roof first, that is the correct order to trace the load path. It sounds like you've read enough to know that this roof is not properly tied. You asked how this could be done safely and you know enough to know that what you are looking at isn't safe. One solution is to hang the rafters from a beam at the ridge. A 24' beam would likely be too massive to afford or handle. I would try to use a post from around the center of the ridgebeam down to a properly sized footing. It can also pick up a loft support beam if needed. Another way is to use trusses. You posted a footing size but as yet I don't think you know the loads on the footings, that is putting the cart before the horse.

A pier and beam foundation should be engineered, I've not spoken to an engineer who would sign off on the ones we see pictured here. A post frame also requires engineering but it is something that they can approve. The posts would not be inset in that case, they would be on the perimeter and would run unbroken from footing to top plate. Building prescriptively is another way.

Offline Peaceful Ambition

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #2 on: March 20, 2017, 08:03:48 PM »
Don, thanks for  your concern! I feel relatively confident that our situation (an understaffed, over burdened building deparment and extremely remote property location) will allow us to remain under the radar, but I understand that either way I am taking a financial risk and I am mentally prepared for that should the day come, I surely do appreciate your honesty.

Regarding the build process,  when you say that the roof is not properly tied, are you referring to the nash house or the LH plans as designed? I see a cathedral style ceiling in the LH plans as well although not with the extra headroom the nash house has.

I don't think I'm up for converting the roof to a ridge beam plan, so I may wind up looking at trusses or just leaving the plans as they are in that regard.
Would trusses would allow me the ability to notch in a ledger board and start the partial loft at around 8' on 10' walls  and then have the rest of the house be a cathedral style without creating outward thrusting forces? How are trusses generally lifted, with a crane or are they not too crazy heavy?

I am unsure as to the loading on the footings and I am just going with the contractors recommendation after showing him the plans, we have relatively rocky soil.

What do you think my idea for the floor joists? Do those seem sufficiently beefy for my needs? I'd rather be overkill than under. I understand the best you can do is speculate and an engineer would have the most accurate answers but unfortunately I'll be doing this without the guidance of an engineer.
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Offline Don_P

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #3 on: March 21, 2017, 02:28:24 AM »
I've brought in and set trusses up to about 24' by hand, as well as beams up to 40'. The truss shop printout will have the weight of the truss on it. A number of those shops also deal with post frame buildings and do the engineering as part of the sale. Equipment certainly makes things easier but the ancients were pretty sharp, simple machines work. The "I'm not up for" out of hand dismissals exist in a place between our ears, do recognize that. It limits our options when we start down those thought paths "I can't" vs "How can I". We've also put boom trucks and cranes in some pretty tight places in these mountains, those operators are good and generally not that expensive.

Check out post #88 here;
http://countryplans.com/smf/index.php?topic=14235.75
That is one way to tie the rafters using the floor joists. I would make the birdsmouth notches a good bit smaller than in the drawing to preserve more strength but that concept is much stronger than what you're looking at doing.

Scroll up to post 77 to see a post frame. With the posts extending from footing to top plate there is not a pinned hinge supporting the building, the support posts become braced cantilevered beams.

For floor joists you can check them in the code tables, remember those tables are minimums. I'm not going to check them at this point because the design isn't correct yet. Remember overkill in one part of the chain does not correct the weak link in another part of the chain.

Edit;
Running back up on the roof with that "how can it be done" attitude, lets see how big that ridge beam would need to be. I'll assume there is a post at midspan breaking the ridge into two 12' spans. The ridge will carry half the load of the rafters on each side of it, the eave walls will support the lower half of the rafters. So, the ridgebeam will support an area 12' long x 7' wide, 84 square feet. Assuming the weight of the materials is 10 psf + the 60 psf snow load = 70 lbs per square foot X 84 square feet=5880 lbs. Three 2x12's at 12' long would support this... easier than trusses in my book if you can handle the post all the way down.
« Last Edit: March 21, 2017, 03:46:17 AM by Don_P »

Offline ChugiakTinkerer

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #4 on: March 21, 2017, 08:12:07 AM »
I think this is the part that Don P is referring to: http://countryplans.com/smf/index.php?topic=14235.msg191124#msg191124

And here is how the loft joists are tied to the rafters:



That is for a full loft.  In the timber frame cabin I will build someday I am looking at a partial loft and cathedral ceiling.  For that my options are a structural ridge or scissor trusses.  If I were on the highway system I would have trusses delivered to the job site, and maybe even unloaded on top of the walls.  For my application a ridge beam will be much easier to accomplish.
My cabin build thread: Alaskan remote 16x28 1.5 story

Offline Peaceful Ambition

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #5 on: March 21, 2017, 09:32:29 AM »
Wow! What a lot of good information, thank you guys, this gives me a lot to chew on for a while, guess I have some more research to do. I really like the idea of extending the joists to the eave, giving more headroom AND a nice overhang at the same time without comprimising the roof.

I suppose I'll do some more research on ridge beams as well. My statement about 'not being up for' it wasn't so much an unwillingness or laziness to try as it was a concern that either my wife and I wouldn't be able to lift a beam that size (didn't know you could split it), or more importantly, my concern that because I don't have much knowledge about load paths, etc, and I'm not hiring an engineer I didn't trust myself to try and get too creative outside the plans. But I DO have time before I get to that point to try and educate myself a bit more.

Could you recommend a good resource online or otherwise for reading a bit more about ridge beams? I have some framing books but they don't cover that in much depth.

I sincerely appreciate you guys taking time out of your day to help with our little project. [cool]


Edit: What is the name of that style where the end wall studs reach all the way up to the rafters instead of ending in a wall top plate?
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Offline ChugiakTinkerer

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #6 on: March 21, 2017, 12:43:31 PM »
I don't know that the name strictly applies for those gable walls, but balloon framing is when the walls are built first and the second floor put in after.  The way I plan to build the loft is balloon framing.

it's nothing like a How-To manual, but the International Residential Code is the definitive resource on how to build a house according to code.  It takes a while to understand how it is all laid out but is a helpful reference on how to appropriately size joists and rafters, for example.  Where I am building there is no permit authority, so I can build whatever I choose.  It's important to me to ensure that the structure can withstand the forces that Mother Nature will throw at it, so I will be following code wherever I can.
My cabin build thread: Alaskan remote 16x28 1.5 story

Offline Don_P

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #7 on: March 21, 2017, 05:09:42 PM »
Full height framing is indeed called balloon framing as opposed to platform framing. The reason you would use balloon framing is to avoid having a weak hinge in a wall. The building code says that studs must run unbroken from points of lateral support. In other words from a floor plane to another floor plane, or from a floor to the roof. What the code doesn't delve into very well is that both the top and the bottom of that wall need to be well connected to the points of lateral support. People do a poor job tying the tops of those big walls to the roof pretty often.

Chapter 3 of the IRC, Building Planning, start here;
http://codes.iccsafe.org/app/book/content/2015-I-Codes/2015%20IRC%20HTML/Chapter%203.html
Notice R301.1.0-3
You can build prescriptively following the provisions in the codebook and as long as you follow those prescriptions you don't need an engineer to check it, we've done those things enough times the same way that we know they work pretty much anywhere. So that is what I mean when I say to build prescriptively whenever possible. The codebook then goes on to say that when you cannot build prescriptively you can look for a solution in several referenced standards and those are acceptable methods. Failing that, the parts of the building that cannote be built prescriptively need to be built according to accepted engineering practice.

That is the section where things such as minimum room areas are given, minimum sizes in baths, headroom, etc.

Chapter 8 is where you'll see the ridgebeam pop up;
http://codes.iccsafe.org/app/book/content/2015-I-Codes/2015%20IRC%20HTML/Chapter%208.html
Go to R802.3.1 "Where ceilg joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder... That girder is also known as a ridge beam.

Go to table R802.5.1(8), (there's the rafter span tables that would cover you) scroll to the footnotes under the table. Notice the small table there, what it is saying is that the rafter tie cannot be raised more than 1/3 of roof height above the plate. (notice the next table is the connection requirements between the rafter and the joist to resist thrust.)

So in the cathedral area the roof is not tied, it then needs a girder, a ridgebeam, to support the rafters. It is pointing to an engineered solution for the cathedral ceiling. When I roughly sized the ridgebeam I was using accepted engineering practice... beam equations from the AWC and wood design data and methods from the NDS, see section R802.2

That's probably enough for one bite  :D

Offline Peaceful Ambition

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Re: Peaceful Ambitions - 14 x 24 House
« Reply #8 on: April 06, 2017, 10:32:21 AM »
Don thanks for the link, that has been a great resource, TONS of info so I've been going through that, although the link seems to be a bit finicky for me.

Not much happeneing here yet unfortunately, the weather has been a big obstacle and this is probably the wettest winter, spring we have seen up here.
I did manage to get up and take a picture of what will be the build site, although not without getting my truck stuck in some SERIOUS soup along the way.





Our road seems to have multiple springs bubbling up so while some parts of the road are dry enough to be dusty, others are mucky as hell.

Luckily I know someone with a bulldozer who was able to get up and pull me out!  ;D
Until the road gets dry enough to get some concrete up here, I'm relegated to planning and research (which never hurts) although I was hoping to be started by now.

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