Asked by Josh from St. Louis
Hi, i’m building a gambrel roof barn that’ll be 30’x50′, but i’m having trouble figuring out the pitch and height i want. most of the new designs look too “squatty” compared to the old gambrels in my area. is there a resource for figuring this out? are there traditional dimensions or formulas to guide in laying these things out?
Hi Josh,
Well there are about as many different gambrel roof configurations out there as there are gambrel roofs. There really isn’t a standard, however I know exactly what you mean about the squatty appearance of your modern gambrel trusses.
Most of your pre-made trusses that are designed as a gambrel consist of roughly a 20/12 bottom pitch and a 4/12 top pitch. So you have a really steep bottom pitch and a really flat top pitch. This results in that “squatty” appearance.
Now, I am going to give you a design secret that I have discovered free of charge. 😉
The rule of thumb that I use when designing a gambrel is that the top pitch should be no less than half the pitch of the bottom. In other words if you start with a say 14/12 bottom pitch your top pitch should be 7/12 or greater. If at all possible it looks the best at exactly half. The shallower the top pitch the more “squatty” it will look.
My go to pitch combo is usually 14/12 bottom and 7/12 top. A 12/12, 6/12 combo will work, and so will a 16/12, 8/12. On your 30′ wide barn that 14/12, 7/12 combo should work well. Wider barns will start to need a shallower pitch if the goal is to limit the height of the barn. The opposite is true with a narrower barn you may need to start going steeper to give enough head room in the loft.
Pitch for gambrel roof barn
I appreciate your comments about avoiding squatty looking gambrel barns. I want to build a 40 foot wide and 60 foot long gambrel barn. What pitches would you recommend for it? If on other hand I went with a gable roof , what pitch then?
how about gable roof pitch?
I have often thought the same thing about many of the agricultural buildings I see with gable roofs as well – that the roof pitch looks way too flat. Do you have a range of roof pitch that you think looks best, or a minimum that you don’t go below? This would be helpful when designing a barn or other small outbuilding. Thanks!
How wide can you go with a gambrel
I see you guys have a 40×60 gambrel plan I was wondering if I can go wider then that looking for 80×100 any thoughts
how to…
I built a 12×16 shed with a gambrel roof and am now trying to figure out how to lower the roof so I can haul it to different location. Any ideas on that?
I have a gambrel barn in Nova Scotia, built in 1927. The big timbers are hewn but all the lumber was sawed. It’s 34′ by 40 ‘ with a 16’ lean to section under the eave at the back. This morning I took my level and square to measure the angles used for the rafters. I am making the assumption that the builder used a rafter square rather than calculate with angles. The bottom pitch is 12/7. The top pitch is 8/12. It’s a classic barn with beautiful lines. We built a modern gambrel building 20 years ago that used the semi circle method to determine the rafter configuration. The newer barn is just a bit too squatty, if that’s a word. We should have replicated the angles in the traditional barn. The purlins in the old barn are hewn 8×8’s. Perhaps that allows for higher construction. I have always thought that the pitch of the roof has more to do with snow load and rafter length than anything else. There are only a few of the old gambrel barns left now. It’s a shame but it would be an incredible challenge to find the timber and lumber needed to frame up the old style gambrels.
I have built a 12′ x 16′ shed and I want a perfect pitch gambrell roof if’n possible, I’m 5’9″ tall and I want ta be able ta walk down the middle, I need help