Tag Archives: gambrel

Maximizing Post Frame Gambrel Space

Maximizing Post Frame Gambrel Usable Space With Trusses

Hansen Pole Buildings’ Designer Rachel and I recently had some discussions in regards to maximizing post frame gambrel truss useable space.  Most often gambrel roofs are supported by one piece clearspan gambrel trusses. Largest downside to this type of truss system is lack of bonus room width. Usually you can expect a room from 1/3 to ½ building width with smaller span trusses (generally 24-30 foot spans). Sort of like this:

My bride and I happen to live in a gambrel style barndominium (for more reading on barndominiums https://www.hansenpolebuildings.com/2016/04/the-rise-of-the-barndominium/). It is actually probably more appropriately a shouse (shop/house). We wanted just a lot more living space than what could be afforded by a bonus room in a gambrel truss.

This is what we did…..

Center width of our home is 48 feet. We clearspanned this using 48 foot long prefabricated wood floor trusses, placed 24 inches on center. These parallel chord trusses are close to four feet in depth. With our 16 foot high finished ceiling downstairs (it is a half-court basketball court), this made our second floor level 20 feet above grade. Ends of these trusses are supported by LVL (https://www.hansenpolebuildings.com/2013/01/lvl/) beams notched into four ply 2×8 glu-laminated columns every 12 feet.

This got us across from column to column to support a floor, now we needed a roof system! We utilized trusses much like these, only much bigger:

Our trusses were so much larger, they had to be fabricated in two halves, split right down the center and field spliced to create a whole unit. We utilized the “Golden Ratio” (https://www.hansenpolebuildings.com/2012/06/gambrel/) to create slopes and pitch break points. Our steep slope is 24/12 and our upper slope is 6/12/ On the inside, our slope is 12/12 and our flat ceiling ends up at 16 feet above floor!

We also ended up with a very, very tall building. Roof peak happens to be 44 feet above grade! Living at 20 feet above ground does afford some spectacular views – we look due south down Lake Traverse and can see the tops of tall structures in Browns Valley, our closest town six miles away.

In my next article, I will clue you in on things I would have done differently, so stay tuned!

A Gambrel Pole Barn, Ceiling Heights, and RV Storage Solutions

Today the Pole barn Guru discusses questions about Gambrel buildings, a minimum ceiling height for a loft, and RV storage solutions.

DEAR POLE BARN GURU: Do you make plans for 18 x 20 gambrel roof pole barns? BEN in HOWELL

DEAR BEN: Hansen Pole Buildings can provide materials, assembly instructions and engineer sealed plans for virtually any dimension gambrel roofed pole barn – including your 18 x 20.

 

DEAR POLE BARN GURU: I am building a pole barn house and want to put a bedroom in the loft. What height do I need to have to be able to stand up in the bedroom? BRENDA in SPRING VALLEY

DEAR BRENDA: A quandary exists in providing you an answer as IRC (International Residential Code) makes no provision for post frame (pole) buildings, so therefore IBC (International Building Code) should be code to be used for their correct design.

Under IBC rules minimum ceiling height in these buildings must be 7 feet 6 inches in hallways, common areas, and habitable rooms.

According to IRC, all habitable rooms must have a minimum ceiling height of seven feet. Habitable rooms include bedrooms, living spaces and kitchens but exclude bathrooms, hallways, utility spaces and closets. A ceiling with exposed beams spaced four feet or more apart can measure 6 feet 6 inches from floor to underside of beams. Bathrooms may have a minimum ceiling height of 6 feet 8 inches.

Minimum ceiling height in rooms with sloped ceilings (such as a finished attic space) of seven feet over 50 percent or more of room area. Room area calculation in this case will be calculated as total floor space with walls (or headroom) five feet or greater tall. Areas with ceilings lower than 5 feet are allowed but do not count toward official room area total (IRC rules also include minimum floor space for most habitable rooms).

RV Storage BuildingDEAR POLE BARN GURU: How much will it cost to build a roof only pole structure tall enough for RV while in use as shelter from elements but allowing as much light as possible.
Thanks MARY in SANDPOINT

DEAR MARY: There are numerous variables to be discussed between yourself and a Building Designer (please dial 866-200-9657 to speak with one) prior to being able to give an accurate price. Amongst these will be the height of your current (and any future) RV, as well as its length. Ultimately you may find it more cost affordable to cover one or more walls, as rarely is a roof only structure a most practical solution. For more reading regarding about this subject, please see: https://www.hansenpolebuildings.com/2015/04/roof-only-pole-buildings/.

 

 

Avoiding Pitch Breaks

Pitch Breaks – Steep to Flatter – The Why and How to Avoid Them

I can hear it in the background already, “You just taught us how to do them correctly, now you want us to avoid them?”

Yep…and here is why…

  • More costly (see also #2 below)
  • More labor (because there are more pieces to install)
  • Will leak if not done right
  • Great place for big snow and ice dam buildups
  • If the roof slope is under 3/12 pitch, the paint warranty on the roof steel is usually void
  • Might not be aesthetically pleasing

In most cases, pitch breaks usually occur when one side shed is added onto a main enclosed structure – either at time of original construction, or down the road when it is realized the building was just not big enough (they never are).

Pitch BreakTo begin with, there are alternatives to having a side shed at all which will generally be less expensive, easier to build and provide more usable space. As an example, considering a 30 foot wide building with a 10 foot wide side shed? Just go with a 40 foot width building!

When a side shed of the same slope is included at time of construction, it takes fewer purlins (the top edge of the shed steel of a pitch break has to be supported by an extra row of roof purlins) and, most importantly, the roof steel can run continuous from shed eave up to ridge. There is not a break in the roof plane which requires a piece of “flashing” and have two rows of closures installed in order to avoid leaks.

So, how can pitch breaks be avoided?

This takes stepping out of the land of dimensional challenges.

Consider the roof slope – a 4/12 slope (the most common) means the roof is going to decrease in height by four inches for every 12 inches of horizontal. This means a 12 foot wide side shed at a 4/12 slope will be four feet lower at the low edge than at the main building.

Don’t create an eave height lower than eight feet at the low eave of the shed. If necessary, make the enclosed portion of the building taller, so as to be able to maintain a straight roof plane. Good chance it is less expensive than creating a pitch break, and gives more cubic feet of interior space.

Before jumping into an investment in a building with a pitch break, explore the options – it may prove to be a pleasant surprise