After reading through EaglesS] A-Frame here over at: http://countryplans.com/smf/index.php?topic=9259.0 and talking to a few people about it, I am seriously thinking of building an A-Frame instead of the Little House. I love the looks of an A-Frame in the woods, there's just something about it - don't know what it is.
I've read and heard about the negatives of the A-Frame: No room in the corners, loss of square footage, light only comes in from the ends unless you have sky-lights. (Can anyone add some more?)
The positives that I like are: it seems easier, goes up faster, looks like it would be less expensive, less windows, and no snow accumulation. (Can anyone add some more?)
Would anyone happen to know where I can get some generic plans for an A-Frame? I wish John would have done at least one. I couldn't even find a book about how to build one.
What happens to an A-Frame that isn't built properly? Today, I took pics of a 25 year old A-Frame that is about ready to fall forward. I'm sorry that I didn't get any pics of the front and back of the home.
The piers have separated from the concrete and leaning, the whole house has shifted to it's end, the floor joists are 24" apart and that seemed to far to me. Also, I noticed that the beams were on the very edge of the top of the post. After seeing this, I really am going to give my pier holes and my pier system heavy thought and added strength - no matter what I build. Check out these pics closely:
(http://www.mrmachinist.net/aframe1)
(http://www.mrmachinist.net/aframe2)
(http://www.mrmachinist.net/aframe3)
(http://www.mrmachinist.net/aframe4)
Seems to be a great example of what not to do. Absolutely no bracing. Of course we have no way to know what the land is like so there's some chance that even diagonal bracing may not have saved it. Not all ground lends itself to successful piers. There are some wrinkles appearing in the roofing as well.
How big would you estimate it to be? How big do you estimate needing for your purposes? Upstairs loft?
I feel even with the downsides mentioned there is still an unmistakable charm to an a-frame. I have thought about it many times since that is what I originaly was going to do and I am not ruling it out.(I think I need therapy) There are lots of plans on the internet some free some minimal charge. There is a great book on A-frames and thier history it even has some plans in it I bought mine on Amazon and it is a very good read. "A-frame by Chad Randl" get it read it and then you will really have the bug.
You might be interested in the story of the Nash Cabin and why they switched from an A-frame.
The A-frame story is the last third of the article so scroll down to find it.
http://www.countryplans.com/nash.html
We had another A-frame discussion here a long time ago regarding mostly negatives if I recall correctly.
Couple more A-Frame refs
http://countryplans.com/smf/index.php?topic=2286.0
http://countryplans.com/smf/index.php?topic=824.0
They sure do have an undeniable charm to them.
I don't think I would describe them as "easier" to build than anything else. Especially for a first timer. I don't think there is anything easier to build than a rectangular box, with a roof on it.
I talked to a framer friend of mine from church and I asked him if there was a standard angle for A-Frame roofs. He said for every 12" over go 18" up. I calculate that to be around 34 degrees, does that seem right? Also, do you think most A-Frames should be a certain 'standard' angle or would it depend on the width and/or personal preference?
Here is a front view of that leaning A-Frame. Looks to me like it is around 16x25 or so?
(http://www.mrmachinist.net/aframe5)
There was a recent discussion on how to expand one. That is the only other major drawback that I can think of. It is much easier to expand a traditional box than an A frame. A minor disadvantage to an A frame can be insulation. If you are building it like EaglesSJ (2x8s?), you can be limited to the amount of insulation that can fit in the walls. This would be 7.25 in. of space for an average of R3.2/inch for R-23, great for walls, bad for roof. This can push up costs if you have to put a large amount of foam insulation on the outside. This is mostly a problem for code built houses in northern climates. Any cathedral ceiling place would face the same problem. The A Frames biggest advantage is speed. They are beautiful though. EaglesSJ did an excellent job. IIRC, he was facing time and housing constraints. I've seen them as 18 in 12 and 24 in 12 slope. Personally I would find the longest dimensional lumber piece I could find and make it to a width that was acceptable (16 or 20). This would give the maximum head room for the loft.
heres my a-frame reno pics with extension.
http://countryplans.com/smf/index.php?topic=8958.0
theres alot of wasted space in a-frames, but they truly feel like a cabin to me. I would like to put a window in my kitchen but theres no room to put one since the fridge has to go against the non sloped wall.
Planning cabinets were a huge pain, i already bought them and hope they fit this summer when i install them
ever consider the modified a-frame? it is the design where the floor joists for the second floor extend out beyond the sloped roof and are then walled in leaving the roof framing exposed on the inside of the lower floor and thus, straight walls on the lower floor. a fairly simple change that makes the place feel bigger and easier to install upper cabinets and storage and allows for windows on the roof sides... looks like an a-frame with wings.
I think the A-frame is a very good cabin concept. I think of them as lofts with the rest of the house missing.
There is the concern of getting light and entrance doors in the center of the building. There are some interesting solutions shown here ... by building appendages that can offer windows and door in the middle of the A-frame.
There is another approach that is one that you see in some A-frame styled church buildings: The roofing does not extend all the way to the bottom end of the rafters ... and is held back several feet. Then a "knee wall" can be installed, a fairly high one ... that is full of windows and doors. This way the roof outline is maintained as a simple shape ... two flat surfaces leaning against each other.
JRR reminded me of something I thought of last night. I believe A-frames are a love it or hate sort of thing. Look at how many builders of rectangular box cabins try all sorts of things to get away from having an A-frame loft. From that it would seem many folks don't like A's. The only A-frame I've seen that I actually liked was built using the principles JRR also mentioned (churches). It used large laminated beams ground to peak. There were side walls that "dropped down" from the roof slope. The beams continued out to steel and concrete anchors. Definitely not in the inexpensive DIY category.
Quote from: ajbremer on February 28, 2011, 06:29:11 AM
He said for every 12" over go 18" up. I calculate that to be around 34 degrees, does that seem right?
I think you have your rise, run backwards.
inv tan(rise/run) = pitch in deg.
You had inv tan(12/18) = 33.69 deg.
You need inv tan(18/12) = 56.31 deg.
24 in 12 would be 63.43
I grew up in a hyprid a-frame. The largest room in the house was one big a-frame, around 24x18, with some square rooms connected to it. The interior ceiling was 20 feet i think, no loft. Family and friends always liked the big vaulted room, but the room didn't really get used much unless we had a lot of people over. furniture and such doesnt fit tight against the walls and creates a lot of wasted space. the vertical end walls were not very funtional for seating or storage because one side had a big glass sliding door in the middle of the wall, and the other end had a set of stairs leading to square rooms upstairs. It was a really big room, but it just never functioned well. I personally dont think the advantages of building an a-frame out weigh the interior challenges associated with them in most situations. good luck on you decision.
Very good point shallyman, I will consider what you've said. And thanks for making the math problem more clearer to me MikeOnBike.
I was in your exact same boat two years ago. After a few conversation here and ordering some plans on the internet and a fight with the building inspectors, I ended up with a version of the 20X30 plans offered here. I'm really glad I came around. Cost wasn't to much more and twice as much space. I have all the wood siting in my barn and will start building in early may when the snow melts.
Here's a free pdf download I received from Andy Sheldon designs:
www.Sheldondesigns.com/cabins/A-FrameCabinPlan-5965.pdf
It's for a 22'x36' A Frame. You might have to sign up for their free newsletter Email thing.
That's interesting, Poppy. I never thought about an A-frame having a crawlspace. Always on a slab in my mind.
It would easier to pour one continuous, long footing on each side .. I would think, instead of forming all those singular ones.
Ok, now I'm not thinking of building an A-frame.
About 5 miles down the road is a friend of mines brother, who I've meet only a couple times here and there. Well, I never realized it but I noticed that he lived in a modified a-frame - one that doesn't come together at the top but kind of looks like a barn loft cabin roof (what's that called?). It was similar to an a-frame to me because the walls went to the ground just like an a-frame.
He had a really nice looking place and I don't have enough time right now to describe it all but he said if he could do it again he wouldn't do it. He mainly didn't like all the ladder and scaffolding work and movement that he had to do. He said he only fell once about 7 feet while building it.
Also, another disadvantage of a-frame construction that I didn't think about in the past is adding to it, an addition. In a box frame place you can add to it in the future but it would be difficult to do that with the a-frame.
Other issues were brought up but all in all, I believe I will go back to these 'Little House' plans (14x24) but modify them with 10' wall studs so I can have head room in the loft. I really appreciate everyones a-frame opinions and I still think their beautiful but because I'm a beginner and don't want my build to be slow or difficult - I'll stick with these here 'Country Plans'. Thanks all.
Good choice on your part.
The roof you looked at is perhaps a Gambrel or Mansard style ... more difficult to frame, but more usable floor space. They would be my choice over a pure A-frame.
Thanks for your comment JRR.
Alan, maybe you've mentioned it somewhere and I forget. What's your snow load where the cabin will be?
Hi Don, I never did figure out my snow load yet. There's only a couple of major winter storms a year here in mid-Oklahoma. I went online and found one place where it said the snow load in Oklahoma is: Use IBC 2003—5 psf-20 psf
I'm not sure how to figure out the 'roof' snow load for pitch. I live in Wetumka, Oklahoma. 65 miles South of Tulsa and 70 miles East of Oklahoma City.
For "normal pitches, don't go there, assume the roof is "sticky", use the ground snow load. There is a basic snow load map in chapter 3 of the IRC.
Snow was up to my waist at the cabin on sunday (went to check on it) and so far my prebuilt trusses and 2 hand built trusses are holding fine.
Alan looks like you are smack dab in the middle of 10 psf (50 year data) no harm in assuming weather could continue to be more unpredictable and go for 20
(http://www.designcriteriabyzip.com/images/groundsnowimage.php?pixelx=2078&pixely=1564)
That's from http://www.designcriteriabyzip.com Free for a 3 day trial.
Comment on metal roofs and snow.
This winter one of our big storms was preceded by sleet which gave everything a nice pebbly surface. The snow that followed stuck like glue and was wet and heavy to boot. We snow shoed up to the mountains. Our cabin with its 5:12 had snow as I would expect. Our neighbor's 12:12 metal had the same amount of snow stuck to it as well.
So yes, steeper pitched metal roofs often shed snow more readily than shingled roofs or roof with less pitch, but it does not come with a guarantee.
I also noticed that the house roof that has been on a few years now is not as slippery to walk on as it was when new.
Don, thanks for all of that information on snow load but what does psf change in a persons build? Am I right in thinking only one thing - the rafter width? Like instead of a 2x6 roof rafter a guy might have to use a 2x8 - or a 2x12 even?
Does a heavy psf require a thicker roof sheathing like instead of 9/16 a guy might be better off with sheets of 5/8 thick on the roof?
Now that I'm starting to think of these things, how about the use of trusses and the design of them, collar-ties, maybe even thicker wall stud width to support the weight of a very heavy snow load?
Some things that come to mind,
Rafters are the main thing, you can change species, grade, span and spacing but keep following the load down.
Sheathing does have load and span ratings.
Rafter ties are restraining thrust caused by the roof load trying to spread the angled rafters. The prescribed tie connection changes with snowload.
Studs, only if very heavy loads that would require full engineering or if tall.
Decks, a snow load can be higher than the occupancy live load and that would then determine member sizes and connections.
Foundation, the load must be safely transmitted to ground.
Trusses are engineered for snow load, snow and wind, unbalanced snow and wind, then the worst combination is used to design the truss.
It isn't a good idea to think that a roof will always shed snow.
The lowest live load to design for is 20 psf.
Just ran across this and wanted to comment on the pitch of our roof. We did a 24 pitch roof (every foot over equals 2 ft up) we did this because we wanted straighter walls with more room. The higher the pitch the more room you will have (and the more difficult the build) Many people will post the thread of the failed a frame cabin and why he swapped back to a more common design. IMO building the A's and trying to stand them up is a very poor way of building one of these things. Our method we pretty easy and would be even easier with more man power. After the ridge pole was set in place myself and my friend dan (neither of us over 160 lbs) put in the remaining 50 26' 2x8 rafters. Now had we have built them on the ground and stood them up we would be pushing 400 lbs or more of material so I can see where that would have been dangerous.
Anyways best of luck in whatever you decide. My main reason for building what I did was cost and to be different than everyone else. Ive never liked to follow common practice. Sometimes this comes back to bite me but other times it just makes me smile.
Thank you EagleS] for your comment. I still love a-frames and yours most especially! I've read all through your post and now that you've explained your pitch, it makes me want to go back to the decision to build an a-frame.
Now that your a-frame's been up for a little while - is everything ok with it, is there something you would have done differently if you could do it again...as far as maybe the way you did the piers or beams or anything else?
I'm going to go back and read through your build again, I find it really cool...maybe I'll change my mind 'again'. Thank you sir.
The only thing I would have done differently is put a basement under it. But we didnt have the money last year to do that so I am going to dig it this year under the bottom 1/2 of the house. That will be pretty easy to do since it is so high back there anyways. Other than that there is nothing I would do differently. I am not at all trying to boast or brag but we had to put a gate up at the top of the drive because so many people were stopping in and telling us how much they loved our little cabin and they wish they had of done something like it instead of the one they built. Lindsay and I absolutely love pulling in to the drive and seeing this little thing setting down in the woods. Its just a neat little place. I liked it so much that I built a matching home fore my chickens!
I also like the how strong the place is. There is no other design out there that will give you the strength of an A. Everyone triangulates in between their piers and basically anything that needs bracing. My entire house is a triangle. :)
Alan, now that we have the snow load question answered there is another. What is the soil like? How much weight can it carry? Is it wet/moist most of the time, etc. The county should have that information available (hopefully). That will determine foundation issues; if piers and footings, how many, what size?
There is a web soil survey available... http://websoilsurvey.nrcs.usda.gov/app/ (http://websoilsurvey.nrcs.usda.gov/app/) That may help. Some soils are simply not well suited to piers.
What foundation does your current home use? What is typical in the area (and has not listed or developed other faults? I believe ScottA said elevated slabs are common in his area od OK. That's a concrete block stem wall a couple courses high and a poured slab within the full perimeter.
I have a fondness for A-Frames, at least the uniqueness of them and perhaps the speed of enclosure framing them. Beyond that I would not build an A-Frame after living in a woodstove heated house with a steep roof. Climbing up a relatively tall steep roof several times a year to clean a chimney is no picnic, not to mention cleaning it once you are up there. One slip on that roof and it will be a quick trip to the hospital. I'm old enough not to court danger.