Gable and side wall overhang....necessary or not?

[TimboTractor]

I've always been kind of a "form follows function" kind of guy and I just can't see the reason for overhangs on a pole barn other than aesthetics.

Is there any real benefit to building overhangs other than looks? I need to order my trusses and will probably get them with zero overhang.

 

[paulharvey]

I've always been kind of a "form follows function" kind of guy and I just can't see the reason for overhangs on a pole barn other than aesthetics.

Is there any real benefit to building overhangs other than looks? I need to order my trusses and will probably get them with zero overhang.

With a pole barn, you would typically want over hangs, just to keep the covered area a bit dryer in the rain since you don't have walls. Let's say you have 24 ft wide, and rain blows in 2 feet; you only have 20 feet of dry storage. If you had 2 foot over hangs you would have 24 feet. I would not do a gable overhang; not worth the extra truss iMO.

 

[square1]

I'll take a [picture of what is left of my neighbors ~25 year old pole building built without overhangs. That should convince you they're necessary.

 

[Deerherd]

Where you get snow it keeps the snow from piling up against the building and when it rains it helps keep the rain from washing out around the building. It's not a lot more expensive and IMHO makes the building look much better also. Good luck!

 

[dave1949]

I would put overhangs everywhere. Besides rain drainage as Deerherd said, it is a protected place to install lights and electric service entries out of the weather.

Overhangs do have a function IMO, they add protection to the structure. We don't use a truss for building a gable overhang here.

 

[Gary Fowler]

You don't need an extra truss to make gable overhangs, just extend your roof purlins? or what ever you call them out over the edge. You do have to account for the extra length on the wall with your trusses though.

I like to have extended roofline on the whole perimeter of any building at least 16" to keep the rain runoff at least a few inches from the post supports. Also if you put on siding, you don't want the water running down the siding and back inside your building.

The idea of not using overhangs is "pennywise and Pound foolish" as the old English saying goes.

 

[TimboTractor]

It will be enclosed with walls, 40 × 72. Probably a lean to on one side wall....no need for a overhang and soffit there, I'll just scab in rafters to the trusses and extend the roofline on a flatter pitch as the trusses will be Gambrell with attic. So, that leaves one side wall and two gables....and I'm considering a lean to at some point in the future on the other sidewall. It snows here about once every 3 or 4 years.

 

[EddieWalker]

No, you don't need over hangs. They wont make any difference for protecting the walls from rain, or the damage water causes to the bottom of the wall when it hits the ground and splashes up. The advantage to having an overhang is it allows you to vent the attic space through a protected area. This is called the soffit, and it's where you will find the vents on houses and barns.

If you are going to have an attic, you need air to flow from the bottom part of the roof to the highest peak. Heat rises, and this movement keeps the wood in your roof system dry. The air flowing over the wood removes condensation and any other moisture from the air.

If you are going to have a metal roof, air flowing from the soffit to the peak will cut down, and sometimes eliminate the roof from sweating. Sweating is caused from condensation forming on the inside of the metal when the air temperature changes from the outside to the inside enough to cause the moisture in the air to solidify.

If you are going to insulate the roof, then you don't need overhangs of soffits if the insulations is against the metal roof and thick enough to stop condensation from forming.

If you are worried about stopping water from coming off your roof and hitting the side of your building, or splashing up from the ground when it hits the ground, install gutters. That splashing causes a lot of damage!!!!

For an overhang to actually protect the side of the building, it needs to extend 6 feet or more. This is also called a porch, and it's a very effective way to protect a house. You just need to do it all the way around the house for it to work.

Eddie

 

[s219]

I think it's very important, mainly to get the roof's dripline away from the building, poles, and any window/door openings. IT will reduce moisture problems and keep the poles from rotting a lot longer than if they were always swamped. Second, it gives you a place for soffit venting, which combined with a ridge vent is also very good for your building's longevity -- the added ventilation will reduce internal moisture and summer heating and reduce temperature extremes on the roof.

I went with 12" overhangs all around on my barn. I see many barns with no overhangs, and think it's just foolish. I want the building to last a long time and not have moisture problems inside or out. Plus, buildings look a lot better with overhangs in my opinion.

 

[kco]

I would definitely go with overhangs. As others have said I think they greatly improve protection from the weather. As deerherd said they are particularly good for snow. My garage does not have overhangs. Adding them is on my "to do" list.