One of the more complicated decisions that goes into the process of erecting a large, modern farm shop is how big of a door to install, what kind of door it should be, and how to incorporate it with the building’s structural design.
“It’s critical to make door size and design one of the early steps in designing a farm shop,” says Jason Myrvik, general manager, Midland Door Solutions. “Big doors need to be integrated into the design of the building itself. The worst-case scenario would be to put up a building and then go shopping for a door. That is going to waste a lot of your time and money, and probably not have a very good result.”
There are three common types of doors often used on farm shops, including overhead, bi-fold and hydraulic. Each design has attributes that need to be factored into deciding the best door for a particular shop.
Overhead doors are the familiar garage doors that roll up and sit inside of buildings. Their design requires 22" to 24" of open space above the door’s header for the door’s tracks and operating system. “We offer overhead doors up to 40' wide and 32' high,” says Chad Soderberg with Raynor Door Authority. “Thirty feet to 36' widths are now common on farms.”
Bi-fold doors have a horizontal hinge across the middle of each door. A system of cables or nylon straps raises the bottom of the door straight up, folding the door into a horizontal V. “Some bi-folds use cables for their lift system, and there can be problems with keeping the cables spooled correctly,” Myrvik explains. “Newer bi-folds have the option to use nylon straps, which reduces problems with things getting out of sync.”
Hydraulic doors are essentially wall sections, hinged across the top of their frame, that are lifted open or closed by long hydraulic cylinders mounted to each side of the door frame. They require electric-powered hydraulic pumps and controls. “Hydraulic doors have the fewest moving parts and require the least ongoing maintenance,” says Zach Campbell, engineer, PowerLift Hydraulic Doors. “They’re simple to operate and are among the fastest opening and closing door options for large openings.”
All three of these doors each have defining attributes. Consider the following:
- Building designs often must be modified to accommodate the loads of bi-fold or hydraulic doors. Most building manufacturers and contractors are well-versed in adjusting their buildings’ designs to support the extra weight and loads of bi-fold and hydraulic doors. Some door manufacturers offer door frames that help support the door and reduce the need to reinforce the end wall of the building.
Some door manufacturers offer do-it-yourself kits as well as factory-installed doors.
“Our Build-Your-Own-Door (BYOD) kits are popular with customers capable of doing the work,” says Mike Schweiss, owner of Schweiss Hydraulic Doors. “BYOD kits save the cost of shipping the big awkward assembled components, and some farmers enjoy the satisfaction of building it themselves.”Midland Door’s Myrvik encourages those considering the DIY route to define in advance who is responsible for warranty issues after installation.
“Not many farmers have the equipment and manpower to lift and hang a one-piece 50’x20' mono-frame door. Having a manufacturer’s crew deliver, assemble and install a big door costs money, but it’s a pretty seamless process,” he says.
- To reduce shipping costs, some manufacturers design bi-fold or hydraulic doors, then ship the components to a subcontractor to assemble and install them on-site. “What if the subcontractor welds or assembles the components to the wrong specs?” Myrvik asks. “Who’s responsible for warranty work? We’ve had numerous calls where we had to go repair another manufacturer’s door because it wasn’t installed correctly.”
- Consider long-term water intrusion. When a bi-fold door is in the raised position, its upper surface slopes away from the building. When a hydraulic door is fully open it can go slightly beyond “level” and slope toward the building. Over years of summer showers, enough water can run back toward the building to create moisture problems with frames and insulation if doors aren’t positioned to drain water away from the building every time they’re opened.
- The trusses on the bottom outer edge of hydraulic doors have a nearly magnetic attraction for snow removal equipment. They protrude up to a foot or more away from the bottom of the door, are easily buried in snow, and aren’t designed to act as protective bumpers.
- The lower edge of hydraulic doors sweep out and up as they open. Vehicles must be parked outside the sweep zone. ATVs and light pickups parked too close to hydraulic doors have been picked up by their front bumpers.
- Bi-fold and hydraulic doors in the raised position can act as a wing in strong winds.
Most large-frame doors are designed to withstand at least 35 mph winds in the open position. “Some jurisdictions require resistance to higher wind-loads,” says PowerLift’s Campbell. “We’ve designed doors to stand up to 200 mph winds. Make sure you understand the wind rating of the door you choose.” - Plan for the evolution of buildings. “You really can’t upgrade a storage building into a heated shop by just adding insulation to the existing door,” Myrvik says. “An insulated bi-fold or hydraulic door requires a heavier frame and different design to support the extra weight of the insulation and any inner sheeting or lining you put on the inside of the door. If there’s any chance you may upgrade a building to a shop in the future, install a door from the beginning designed to handle the additional weight.”
- Opening and closing large doors can cause a lot of a shop’s heat to escape on a midwinter day. A single 10'-to-12'-wide overhead door on a sidewall of a building allows for quick and easy access for pickup trucks, forklifts and small machinery without having to open and close a mega-door. Some shops pair medium-size overhead doors on opposite walls to allow drive-through access for semi-trucks and trailers.
- Hydraulic door safety. Some hydraulic doors use restrictors and orifices in their lift cylinders to slow the fall of doors in case of a failed hydraulic hose. They will slow the door’s descent, but they won’t stop it from landing on anything underneath it. Other designs use velocity fuses that lock hydraulic flow in case of a failure, freezing the door in position.
- Traditional sliding doors make good shop doors, especially if they are power-actuated and radio-controlled. “We can automate new sliding doors or retrofit existing sliding doors as long as they slide easily on their track,” says Scott DeBoef of Scott Ag Doors. “We can work with two 30' doors for a 60' opening. Our Propel-brand operators mount so no there’s no extra header height, wall height or structural reinforcing required. They’re radio-controlled, so you can open and close them from the seat of a truck or tractor. Since the frame and sheeting of sliding doors is a lot simpler than bi-fold or hydraulic doors, the system ends up being half the cost of a bi-fold or hydraulic door. Sliding doors with a power-actuator are a functional option at a fraction of the cost.”
Read more from Dan’s shop building series:
Start Here When Building A Farm Shop
Expert Tips to Avoid Remorse When Designing A Farm Shop
Farm Shop Concrete: One Chance To Do It Right
