Fire Ratings for Historic Wood Doors

Information on how to find code-compliant fire-rated doors, and what you need to be qualified to build them yourself. March 12, 2009

I received a call recently to do some replica doors. The building is a named building in a historic district so all of the detailing will have to be exact to what's already there. This is not a problem. The architect further explained that the local fire marshal needs most of these doors to be fire-rated. All of the specs I have so far are just to pass different burn ratings (30 minutes - 60 minutes). The doors are cypress. So how can I (or where do I) accomplish this?

I've read the "veneer to a fire door" post and understand most of the posters perspectives. Is there a custom door manufacture that can build truly custom doors (enough to satisfy the historic commission) and can provide the necessary fire-rating documentation? If not, does anyone know the process to get this done? The architect stated that he's burned up doors to get approval but I’d just like to hear from someone else who's been there, done that.

Forum Responses
(Business and Management Forum)
From contributor S:
If you post the exact specs needed we may be able to provide better answers. It may be just a fire rated coating that is needed to meet the specs.

From the original questioner:
I don't know the specifics of the fire ratings. All I was told was that there needed to be different doors spec’d for different ratings. The architect mentioned 20, 45, and 60 minute ratings. Would a coating achieve any of these numbers? I’m just trying to gather some initial information on the best way to go about meeting this order (or determining if I can).

From contributor B:
A coating is not going to achieve a code requirement for 20-45-60 minute openings. You could have a door burned at an accredited laboratory but I doubt you have neither the lead time nor the inclination to spend the many thousands of dollars required to get the three burn tests.

The easiest course of action is to find a manufacturer who is licensed to build and label custom stile and rail doors and have them do it. Depending on their license they may be able to do any style of door so long as the core and construction methods stay true to the method they used to become WH or UL certified.

Also keep in mind that the jambs may also need to be labeled depending on code. 45 minute and 60 minute openings will require it for sure. So if the architect is specifying wood jambs on these doors be aware of the additional associated costs.

From contributor B:
Minute ratings are used on wood doors and frames as well. Technically speaking the IBC/UBC could care less what the door is made of as long as WH or UL say it can provide the required separation.

From contributor S:
Does this include solid wood doors? I ran across some mfg's that showed fire rated doors which were visually wood but they don't provide any info on whether they are solid or veneered.

It looks like hinges (steel), hardware, latching, and hold open devices come into play also. I ran across an outfit that custom makes and labels wood fire doors/jambs and you can order them bare and finish them yourself. I'm sure there are others closer to where you are.

From contributor B:
I'm in Colorado. Yes you can buy solid wood stile and rail doors with 20, 45, 60 and 90 minute ratings. 20 minute doors can come in a variety of constructions that many would consider typical. When you get into the 45-60-90 minute doors you will see a lot of appliqué construction i.e. the core will run the entire width and height of the door and be capped on the edges with thin layers of solid wood while the stile/rails/raised panels are being applied to either side of the core. Depending on the fire core thickness you could have a 1 3/4" thick door that is 1 1/4" worth of solid wood with 1/2" of core. There are probably hundreds of variations out there but the common thread is that they all have had these methods tested and are certified to build and label doors to that end.

We currently carry a license to manufacture 20-90 minute labeled, positive pressure doors along with 20 minute labeled wood jambs. We can use any wood species/material available to us as long as we follow the construction methods (including the various fire cores) that were used to pass each burn test. Hardware is opening specific, but you are correct in that anything going on a labeled door needs to be UL or WH certified (hinges, thresholds, door bottom, locksets, closers, coordinators, and etc).

From contributor S:
My only experience in fire rated doors was with the build out of my own building, which was more of a high tech contemporary lab set up for performing historic conservation of wooden objects. Still, I have learned a bit more in the research, which I enjoy. UL headquarters used to be a client of mine and it was very cool to see the testing that went on in the bowels of the operation.

From contributor P:
It's worth making sure the Fire Marshal is following an existing code. I don't know the law on this issue, but I have found building inspectors enforcing fire rules and energy saving rules that don't exist. They may mean well, but they can make mistakes.