Offering rugged strength, economical price point and low-maintenance requirements
If you are unfamiliar with the standard sheet door, you may be surprised to learn that it is one of the most cost-effective and reliable door systems available. But if you have worked with them in the past, you probably appreciate the rugged strength, economical price point and relatively low-maintenance requirements that make them ideal for many high-traffic buildings. That’s not to say they are perfect for every situation. For one, they are not fire rated; and while wind-rated series are available, the mechanics of the wind clips render the doors inoperable during high-wind events. Also, if you require energy efficiency, even an insulated sheet door offers a comparatively low R-value.
Installation
Sheet doors are easy to install, but we always recommend you hire a qualified door expert who is familiar with the process and product. An experienced installer can usually hang a standard door in about an hour. Like any project, there are certain pitfalls to avoid. Here are the three most common issues that challenge a proper sheet door installation:
1. Brackets out of level. This can cause the door to lean to one side when opened and/ or cone (gather into an uneven roll around the barrel) when closed.
2. Improper guide placement. If guides are set too close together the door will bind and drag; too far apart and it will not fit securely into the guides, which will affect its wind rating.
3. Improper spring tension. Too much tension and the door will slam up; not enough and it will be difficult to open. Both are safety hazards.
Brackets
When properly installed, brackets support the full weight of the door and any pressure required to open it, but they are only as secure as the wall or jamb to which they are attached. In general, a properly installed and undamaged bracket can be used again on a replacement door of the same model and manufacturer.
 |
| Photo courtesy of DBCI |
Guides
It is important to match the guides with the corresponding door model to ensure proper engagement. Mismatched doors may still fit into the guides because sheets are usually built using the same profile, but their overall performance will suffer. At loading docks and freight terminals, there is added risk of damage from forklifts. To minimize this risk, impact-resistant rubber guide assemblies can be used in place of standard metal ones.
The Sheet
Constructed out of seamed strips of corrugated steel (usually 26-gauge), the sheet is the simple, metal divider that lines warehouses, freight terminals and storage facilities throughout the country. The efficient manufacturing process means doors of virtually any length and height can be quickly assembled in a range of colors. Most sheets are permanently seamed together, but the recent launch of [DBCI’s] Curl-Lok has introduced doors into the market with interlocking panels that can be replaced on-site when damaged.
Bottom Bar
Running along the bottom edge of the sheet is the often overlooked bottom bar. It reinforces the overall strength of the door and is usually fitted with handles and step plates to assist with day-to-day operation. Fitted into the underside of the bottom bar is the rubber astragal, which makes a seal between door and floor to form a barrier against the elements. Because it is in regular contact with water, debris and friction, the astragal wears faster than the rest of the door components.
Springs
The springs are the central nervous system of a sheet door; the vital components that determine the overall operation of the door. And just like the body’s central nervous system, springs perform best when they experience consistent use. It’s a good idea to open and close doors that have remained shut for an extended period of time. Springs that have remained dormant usually benefit from a heavy application of white lithium grease. That can be a challenge on a sheet door with a closed barrel, but is best achieved through the access holes at the ends of the drum.
Accessories
The standard sheet door is straightforward and simple, but there are plenty of accessories to adapt a door to an owner’s preference. An electric operator is usually standard on larger doors, but it is not uncommon to install them on small doors. An electrically operated door can also be fitted with safety edges to stop a closing door that comes down on an obstruction. Header seals and side draft stops (both employed to keep out the elements and reduce unwanted air flow), vision panels, hoods and insulation are some of the more common options found in the field.
T.J. Kuehn is the marketing brand manager at DBCI, a manufacturer of steel roll-up doors at facilities in Douglasville, Ga.; Houston; and Chandler, Ariz. He has more than 15 years of experience in product development and marketing for both consumer and B2B brands. To learn more, visit www.dbci.com.
