First, a couple of notes…
- There were some questions about last week’s Fixed-it Friday post, so I added some more photos. Click here if you want to take a look.
- I’m making some changes to iDigHardware, but don’t panic! You will still be able to find everything you need. If you have any suggestions or comments about the layout of the site, feel free to leave a comment below.
Now, for today’s post:
I love a hardware challenge, and I’m lucky to be in a position where Google is helping people find me and iDigHardware. Sometimes the questions are stumpers and I post them here as WWYD posts to see if any of you have run into similar situations. I always appreciate your feedback!
Last week I received a really interesting question. The city of Sioux Falls, South Dakota, made a local code modification that requires certain stairwell doors to be automatic-closing:
3. Interior doors located in exit enclosures, smoke proof enclosures, and exit passageways in Group R and I-1 occupancies shall be automatic-closing fire door assemblies in accordance with NFPA 80 and controlled in accordance with NFPA 72..
An automatic-closing door is one that is held open until released during a fire. Although NFPA 80 defines an automatic-closing device as “a device that causes the door or window to close when activated by a fusible link or detector,” the IBC requires doors in many locations, including exit enclosures, to be automatic-closing upon smoke detection (not heat).
Why would the city want these doors to be automatic-closing, when typically self-closing doors are acceptable by code? Here is their commentary:
The Fire Prevention Division, upon inspections of multi-story residential occupancies, continually finds stair enclosure doors held open by wood wedges. This [code modification] proposes to require any door that serves as the last defense to prevent fire and/or smoke from entering into a vertical stair and smoke proof enclosures to be provided with an automatic door closing device that is either tied into a fire alarm or a smoke detector in the vicinity of the door. This provision will be applicable to stair enclosure doors in transient or non-transient residential occupancies and assisted living centers in new construction only.
Kudos to the city for trying to avoid residents using wood wedges to prop open stair enclosure doors for convenience, but what if the building owner doesn’t want to have the doors propped open? In many multi-family buildings, there are security measures that prevent someone from entering a tenant floor from the stairwell unless they are authorized to do so. Which product would meet the owner’s and occupants’ needs for code-compliance, convenience, and security?
How about the LCN 4310HSA? This is an automatic-closing unit which closes the door when released by a smoke detector – as required by the code modification. A typical automatic-closing unit would hold the door open indefinitely (until smoke is detected), which would not provide the necessary security. But the HSA unit would work like this:
- If someone used the door without opening it past 80 degrees, the door would close immediately – like a self-closing door.
- If someone pushed the door past 80 degrees, the door would stay open, removing the temptation to install a wood wedge.
- After the person has gone through the door, the sensor on the HSA unit would sense that there is no further traffic and would release the door from hold-open, re-securing the opening.
The 4310HSA is mounted on the pull side of the door, so it would be on the stairwell side out of sight from the corridor. There is also a push-side unit – the 4410HSA. These units are often used for doors where large groups of people may exit together like a theater or auditorium, so the hold-open is more of a convenience, but I think this is another great application for the product.