I have been browsing this forum for a few days and have become a member. I find it very interesting. I plan on building my own home on some land that my father-n-law is letting us build on. The thing is, we want to do it with-in our budget, around 40-60k in all. We will have plenty of help too. My brother-n-law is a contractor himself, I use to do low voltage wiring, and my father-n-law is an old time farmer, the type that uses inginuity all the time. We want a simple 1500 sqft home. What are some of the advantages and disadvantages of a gramble style roof ( barn )? The land is slightly sloped so we know we will have either a big crawl space or a partial basement. I can post pics later. I just want to head in the right direction. We want to do this with-in a 3 year span. Can it be done? I have 2 days off per week and during the winter 3 days.
Any help would be very greatful.
I'm building the Victoria's Cottage (with all the bumpouts) which is about 1180 sq ft. It has cost us about $60,000 so far and we're almost done - still need insulation and drywall. The Victoria's design is rather complex; three bumpouts and two porches, three different roof pitches, four different wall heights. I have 21 individual wall panels! I've been working on this almost full time (greatly reduced in the winter) for a little over a year, however my project is entirely solo with no contractor involvement.
Sounds like you have a great opportunity; land, a good budget, help, and some 3 day weekends. I would recommnd that you design around a basic square/rectangle (if this isn't too offensive to your visual sensibilities) . It could be 1 story, 1-1/2 stories, or 2 stories. Gambrel roof is a great use of interior space but with a little more complicated design and build (the added hinge-point needs to be engineered properly). Have you considered a walk-out basement?
w*
I agree on the gambrel roof. Something such as the 1 1/2 or 2 story with a standard roof would be easier to fit into your time frame and budget.
Note that it is easy to extend plans in length such as the 20x30 to 20x40, but widening changes the engineering and is not easy.
There are barn plans out there with gambrel trusses. I bought a set for the barn I'm going to build. This offers a free-span up to 36' upstairs in the loft. Of course, you've got to support the floor trusses, or spend a lot of money to have 36' free-span downstairs! A barn like that would make a great house- I was going to go that route, but the wife doesn't like the gambrel style in a house. Since these nice folks here are in the business of selling plans, and darn good ones at that, you'll have to PM me for the link to the barn plans.
The reason why I was thinking the gambrel roof was because of the second floor is your roof area. I was thinking a house about 24x40 2-story with a half basement. I want to put the wood stove and all the mechanicals down in the basement area. The second floor would be for the kids bedrooms and bathroom. I also was told that gambrel roof was actually cheaper to build because you also have your roof too. I had plan on using Lowes lumber for my structure and milled wood for my trim. The best of both worlds, one for the inspector and the other for my wife and I.
The wife and I like the barn style homes. We already live on a farm so it just made sense for us. I had plan on using floor trusses either way.
Sounds like a cool project and you are not limited to just using John's plans here. The forum is for learning and teaching - helping those who will help themselves.
All plans are welcomed, just need wife approval, lol. :) I actually showed my wife some of the neat homes that are on this site and forum. She did like a few. I think it is just a matter of her making up her mind on a plan and just getting it started. The thing that I have to make sure about is the building inspections. In my area, the county inspector has final say on anything. Somethings he will say ok on and some he won't. We were actually looking at buying a older home and dismantling it but we would have to plane all the wood and get the inspector and engineer's ok to do it. The engineer is about $1500 each time we need him.
Isn't that the craps that you are forced to live in a house that a government public servant likes rather than a house that you like? Where has America the free, gone? [noidea'
I find that remodels - or tear down and rebuilds tend to cost around three times what a new build does. Especially if you need to consider the value of your work and time. If you can get salvage stuff and incorporate it into your project where the time and cost is not excessive, that is great.
That is the truth! I actually had an inspector tell me that it didn't matter what was in the code book, it was his signiture that mattered.
Sorry for the rant there.
We do plan on using some reclaimed wood in our home, as well as milled wood. We would love a log home but again an engineer has to say it is ok to live in and approve any and all chages. We live in an area where many of the rich and famous have their vacation homes. As I said before, it costs alot to have a contractor build you a simple house here. I have met alot of them from my days of doing Audio/Video.
I love the power/ego trippers even more... [waiting]
Somewhere in there I know they mean well. All the inspectors from this end of the state got up and walked out of a meeting/training session I helped set up on grading and using sawmill lumber. I've noticed more states are getting native lumber laws, the "greening of america might help now. The tenderized spot on my head has almost healed up, might try through forestry/state engineering school next time. The bright spot in all that was I did watch a trainload of bootleg lumber move through the area under their noses after that. They shoulda been paying attention instead of scarfing up those free donuts ;D. What came to my job was on grade, the sawyer had simply avoided thousands in fees. West coast and canadian woods don't draw notice, my hardwoods stick out like a sore thumb.
For reuse/demo do be aware that a new round of lead laws kicked in this spring through EPA.
You mentioned basically getting a bonus by having living area under the roof. A gambrel is a type of mansard roof. The mansard evolved because houses were not taxed for space under the roof... in the "attic".
The structure isn't that complex, or needn't be, depending on size and load. Think of the steep roof as walls that didn't quite get plumb and build a simple truss on top, that is the simplest gambrel. My 24' wide barn is built that way, balloon framed with 2' kneewalls, the truss tie is at 8', thrust is very low due to the steep slope, alot to be said for it. The sloped wall space is odd and hard to window or utilize, there is the downside. Pay attention to how others have dormered them as you drive around. A long shed dormer extension of the upper roof works well. Small dormers get kinda funky IMO.
Yeah, I know about the new EPA laws. I do want to keep the sturcture design simple. I was mainly looking at the grambel because of the second floor being built when you build the roof. I have also notice the long shed roofs on many of them that are houses. That is pretty much what I am looking for anyways so it works out. I should be able to post pics of the half acre we are building on on Monday.
I can relate. I read that the state electrical inspector I'm going to be using is considered to be the "authority having jurisdiction". This means I have to comply with the inspector's interpretation of the residential electric code, not with what the code actually says. Hummm, I hope he/she is a straight up kinda person. This nugget of fine print could really be exploited with someone on a power trip.
The aesthetic advantage of a Mansard is that a tall, skinny structure can appear less so. I wonder how all that roofing affects cost?
Have you seen this? http://www.countryplans.com/redic.html
I believe it was done under the budget you have.
Don P., have I ever told you how to carve a grading stamp out of a potato? :)
Got up and walked out... they knew their owners would not like them to listen to what you had to say. They are truly owned by corporate America and the good 'ol boy system. [waiting]
Ohh.. I have a linoleum block around here somewhere :). My wood wouldn't slide under Glenn, nor would I do it. I have no problem standing on their toe and leaning in, but I won't commit fraud. For one, when I signed for my license I said I wouldn't, and two, it's wrong.
Actually their boss, the state head in charge of housing and community development was on my side, he tried to help get it through, helped set up the session, found the funds etc. The grading agency itself was not opposed, they came and ran the training session. The actual trainer was opposed and is a slob but that is a personal not a corporate problem. Our regional head is a by the book kind of AHJ and the rest toe his line. It was probably the sorriest behavior I have seen out of a building official in a public meeting but there were to my knowledge only 3 members of the public in attendance. The public is, I am sorry to say, basically apathetic and stupid. And let's face it grading lumber is booooring. It has nothing to do with corporate America in this instance, the building officials are truly not that bright. The book says it and they are gonna follow the book, it doesn't go much deeper than that. The most legitimate reason was that if there was a failure they felt their jurisdiction's would be dragged into the suit. I asked if that type of suit had ever succeeded, none could point to one. But even the exposure is going to make a county attorney tell them to forbid it unless it is allowed by state law. that is understandable if you think about it. The path is to change the law. The public would have to show enough interest to make that change. So far we, in my state, have not expressed that desire in any meaningful way.
There is also a flip side. To my knowledge I am the only small sawyer in the southeast that has trained. I might have a different feeling if there were many of us, qualified, standing there saying "let us in". It is arrogant to ask for a right one has not earned. Competence is not there, arrogance does not compensate for a lack of competence.
I would like to see it allowed, but I do feel this is serious stuff. If you screw up somebody can die. The system was built for the big boys, by the big boys. The government mandate specifically said this wasn't supposed to be the case. I think there should be oversight of the small mills by the same 3rd party grading agencies that oversee the big mills, and it should cost the same per board foot, not the same minimum fee per month. It could also be done by the land grant universities forestry and engineering programs, what a great hands on training opportunity. If a sawyer does show disregard they should pull his ticket.
I did have to wade through some junk today and the #3 will go back. southern pine with a canfor stamp (canadian stamp on southern wood)... I don't know the story there but it was crap and something is fishy. yes, I've seen stuff from the corporate end. I've also had lumber suppliers try to dupe me the consumer, even the box chains, that is national in scope.
I do have a nice pile of red oak timbers on the job right now. I cleared the site and he wanted to use them for the porch posts and beams. I informed him of the laws and what it would take to get the material graded, have the app forms on the computer, know the grader. It would run about $500. The homeowner is balking at the cost of grading and is now thinking of resawing the beams, which will waste tons of material now that they have dried as timbers and have some checking.
No solutions, just ranting past my nap time :).
Same old story, Don. If they go strictly by the book then they do not accept any responsibility or liability thanks to our litigious society always needing to blame someone.... we have been brainwashed into that BTW.. :)
Our rough sawn lumber is still as good as a lot of the graded crap we get nowadays anyway. We just didn't pay off the right people.
Lots of hundred or more year old buildings around here and not a stamp to be seen.... [waiting]
[Lots of hundred or more year old buildings around here and not a stamp to be seen.... ]
I couldnt agree with you more. I use to live in NH where there are still homes standing from the late 1700 and no stamp. Sometimes I think it is just another way for the state government to get money outta people.
I agree to an extent but I've seen both sides, and sorry to sidetrack us YRN, feel free to get back on track.
The state doesn't get much of the proceeds, the grading agencies cover their costs and the consumer pays for another layer of "protection". I've worked on enough old buildings around here that are framed in hardwood that was the culls from the furniture industry. If it wasn't structural enough to hold up a bedpost, they decided it could be a joist ::). The fed in the '20's decided that a standard was needed so that when an arch or engineer specified a #2 of some species the strength was there no matter who I bought that #2 from. The concept is sound. They gave the authority for implementing that to a quasi private/govt body to write the rules and implement it. These are the same "voluntary product standards" that give us plywood of certain properties or asphalt of different grades. industry does know more about its product than congress. Unfortunately it also does not incorporate the small time operator into the mix very well. Not neccessarily out of malice, it just doesn't fit into the machinery efficiently. Now that we realize it might be smart to do some of these things small and local we are bumping into their foot on our back. One downside in this is that lumber on the jobsite. I can make trim, siding or non structural stuff out of it and often do. It is only when I want to frame with it that we have a problem. But, to give one example, the forest products labs has tested trusses made of pine and red maple, an overstocked tree in my forest. Where in pine the failure is the truss plate pulling out of the wood, in maple the failure doesn't occur until the metal itself tears.
And to the comments I often see that houses are standing from many years ago, do think about the number that were standing and the number that remain... we bury the dead, one or two is not proof of something, we should wonder why the many failed. These are all human interpretations that we make without thinking all the way through sometimes.
And yes the inspector is required by our attorney to stricly limit our liability so that our taxes to cover his mistakes does not increase... at the root of all these problems, is the guy in the mirror :).
Thank you all for your insite. I will keep all this in mind when I hopefully try to break ground in March of next year.
Without sidetracks we would only learn about half as much, Don. :)
Just a few comments on gambrel roof;
Without any horizontal tie between the hinge points (where roof slope changes on each side of ridge), there is high risk of spreading the roof.........I have recently seen the results of this behavior with an owner-built gambrel here in New Jersey.
It is possible to design and install a "moment-resisting" joint at the slope-change location..........however engineered design should be considered for such approach.
Another idea.......use ridge beam and additional beams at each slope-change location. Of course this only works if you can accept columns for each beam ........unless length of the entire roof is only about 20 feet or less and design snow loading is not more than about 30 psf.
Good point John. I might have overly downplayed the thrust as negligible on the very steep roof of a gambrel on kneewalls. I had looked at the steep slope and discounted the thrust, probably unwise. I had not checked it.
If you don't mind I'd like to walk through the math to see if I'm understanding it correctly.
My barn has a 12/5 steep pitch, the inverse of the upper roof, 67.38 degrees.
tangent is the ratio of opposite side over adjacent side
tangent of 67.38= 2.4, or another way of saying that is, the vertical load will be 2.4 times the force of the horizontal thrust.
1/2.4= .416
If I multiply the vertical load on the roof times .416, that is the horizontal force pushing sideways on my kneewall.
My roof is framed on 1.33' (16") centers, the total load on the roof is 35 psf the barn is 24' wide, horizontal span of a rafter on one side of the ridge is 12'. Vertical force on that 12' span is 560 lbs
560 X .416= 233 lbs pushing horizontally on each stud of the 2' kneewall in my barn at design load.
I am taking all this in. [cool] I often wondered what the load was on roofs. Keep it coming.....I'm learning something.
Outward thrust (in PLF) for symmetrical gable frame roof with uniform load is calculated as..........(wL/4) x (12/s)............where w is uniform load in psf, L is total span of the gable roof (from wall to wall) in feet, and s is the vertical rise (inches) per 12 inches (standard way of describing slope).
See "Design Example - Outward Thrust Force" on the following web page; http://www.structural101.com/Structural-Ridge-Beam.html (http://www.structural101.com/Structural-Ridge-Beam.html)
For the data by Don P.........w = 35 psf..........L = 24 feet..........s = 5................Horizontal thrust (per linear foot of roof; PLF) = (35 psf x 24 ft /4) (12 in / 5 in) = 504 lbs / ft (PLF)
For rafters spaced at 16 inches.........Horizontal Thrust (lbs) = 504 PLF x (16 in /12 in/ft) = 672 lbs
You can of course eliminate the second step by starting with uniform load (w) in PLF, which would be 35 psf x 16/12 = 46.33 PLF
Basic formula can be derived by the usual analysis methods.........taking moments about the peak equal to zero since joint at the peak of gable roof is a hinge. You solve the moment equation for the horizontal thrust force............and then substitute value for ridge height from relation between ridge height and roof slope (simple proportion).
Basic formula can also be derived by considering the gable as a simple truss (which it is). For such analysis, point loads are applied to the three joints.
Many (probably the majority) of gable roof frames do not have adequate connection between low ends of rafters and attic floor / ceiling joists (rafter ties) to satisfy current design requirements using building code provisions. There are two main reasons that such roof remains standing;
(1) Full design load has not been applied (yet)
(3) Failure capacity of whatever connection has been made is much greater than design capacity
(2) Roof sheathing acts as a diaphragm to resist outward movement of the rafters
Over time however, connection capacity is reduced (for various reasons including cyclical loading from wind and snow & roof leaks that damage wood at low ends of rafters) and ability of roof sheathing to act as diaphragm is also reduced (due to loosening of connections). When design loading (something close) is finally applied, movement can then occur much more easily.
However.......based on my experience, most cases of gambrel roof spreading occur during construction, either before roof sheathing is installed or (more likely) as roof sheathing is being installed.
Can't be... I think I see the problem, my oddball notation. I called the steep pitch a 12/5, your math is for a 5/12 pitch. Let's convert it to standard notation... it's a 28.8/12 pitch. Doing it that way I'm coming up with ~116 lbs thrust.
(35 x 6) (.416) (1.33)=116.
Exactly half what I figured... ah, half each span's load is supported by the wall.
http://windyhilllogworks.com/Calcs/RafterThrust.htm
My calculation is for a 5 on 12 slope.........which is what I thought the slope is for upper (triangular, gable) part of the gambrel roof assembly. The basic formula is correct for any gable roof with rafter tie across low ends of rafters.............or without rafter tie but supports that can resist the outward thrust force.
As noted in the link referenced in my previous comments...........the force calculated per the formula is consistent with required nailing (rafter to attic floor / ceiling joist) listed in tables in the standard Wood Frame Construction Manual (WFCM). Derivation of the formula is based on standard structural engineering principles. When using the formula......understand that it is only for the stated conditions........uniform loading on a symmetrical gable.
The formula is not applicable at low end of the "wall" part of the gambrel roof assembly (with 12 on 5 slope or 28.8 on 12 slope, not sure now which it is; diagram would help)..........only the upper gable (triangular) roof part (on top of the sloped "walls").
Without any rafter tie (ceiling joist)........the relatively large (672 lbs per rafter) outward-acting horizontal thrust force would be applied (by low ends of rafters with 5 on 12 slope) to top of the "walls"...........which (in general) do not have capacity to resist such force. Of course, without snow on the roof, the outward force is much less since we are dealing only with "dead load" of the roof........not full design snow load. Typical result for a gambrel without rafter tie is for some horizontal movement (spreading) at the slope-change points. Such movement can be relatively large.......on the order of 2 inches..........resulting in noticeable sag in the ridge. This condition also sets the roof up for total collapse in the event of heavy snow load later.
Once again -thanks for the clear explanations and discussions, jfmann and Don_P.
It helps all of us who don't get around the engineering end much.
Thanks to all of you :)
jfmann, this is a quick sketch from memory. The upper tie is somewhat unconventional and dictated the width of the upper roof... 16' long tie. The joints are all in one flat plane with 1/2" ply gussets nailed over them, Ive shown the peak gusset, the pitch break and tie is also gusseted. It might be good to use this as something to dissect but I'd also like to know how to figure the forces and build this as a moment resisting frame... a more conventional hayloft.
(https://i180.photobucket.com/albums/x109/windyhilll/gambrel-2.jpg)
I will throw this into the mix for what it is worth. This is a revised version of a site built gambrel truss I first posted to the freee Download section in 2002.
As it says on the plans, consult a local expert for appropriate loading and engineering for your area (or have a truss company build it).
http://www.countryplans.com/Downloads/Gambrel.pdf
(https://i1009.photobucket.com/albums/af219/countryplans/Gtruss.jpg)
LOL, it seems I'm defending a balloon framed untied kneewall and John R has drawn his rafter feet down on the floor using it as a thrust resisting tie. This might be a good exercise in finding some limits [cool]
30/60 is a more typical gambrel, if we want to shift the discussion of forces to those pitches it might be easier. 6.93/12 and 20.8/12 would be the pitches.