Times change. Accidents happen. We learn. Prior to the 1960s, is was not uncommon for automobile dashboards to be metal and seats to lack seat belts and head support. Similarly, we continue to learn and improve construction materials, techniques, and building codes to make us all safer.
The March 3 tragedy at the Preston Place condos offers an exemplar of some of those changes. Recently, I spoke with Perry Wallace, 30-year construction veteran and VP of Construction for Transwestern and Dallas Fire Department Deputy Chief Michael Price. I wanted to understand the advancements that have been made over the past 38 years since Preston Place was built. Transwestern is currently building the Laurel apartments at the corner of Preston Road and Northwest Highway. Chief Price was the lead firefighter on the Preston Place fire.
Sprinklers for Fire Protection
The biggest change has been the requirement for sprinklers, even in smaller multi-family dwellings like the Laurel. Depending on the size of the building, most wood-frame, low-rise buildings fall into either 13 or 13R categories. It turns out that the Laurel apartments’ two buildings will use both categories. The taller, larger corner building will use the full 13 specification including a fire pump for uninterrupted water pressure during a fire. It requires more sprinklers per square foot as well as sprinklers in voids between units and attic spaces. The smaller, shorter north building only requires 13R measures placing sprinklers in major rooms (i.e. not closets, voids, or attics). The difference has everything to do with a structure’s overall bulk.
Wallace said that mandatory sprinklers have been the biggest advancement, by far, in fire suppression. This makes sense as fire isn’t spreading while waiting for fire fighters to arrive on the scene.
Sprinklers have also gotten smarter. The newer systems have sensors whereby if a sprinkler head is activated, the fire alarm is also tripped if it hadn’t been already. This acts as a back-up in case the smoke/fire alarm failed to sound.
Unfortunately, older buildings, including older high-rises, did not require sprinklers when they were built. The cost to retrofit is prohibitive. Interestingly, were the high-rise originally planned for the Preston Place plot been built, it would have required sprinklers. As it was, a three-story building didn’t require them at the time.
For those wanting to read more about fire sprinklers, the American Fire Sprinkler Association is located right here in Dallas. (The things you learn writing for Candy!)
Draft Stops and Fire Blocks
Next on the list are draft stops and their close relative, fire blocks. Draft stops are barriers between unit attic and ceiling spaces. For example, if there are two units below a common roof, a fire gaining access to the attic space would travel unencumbered across to the second unit. A draft stop places a barrier (usually sheetrock wall) between the combined attic space to separate and keep fire out.
Remember how the Titanic sunk because the water-tight compartments didn’t connect to the ceiling? This flaw allowed one compartment to fill and overflow to the next compartment like an ice cube tray. Older buildings are like that…only with fire.
From how I saw the fire progress at Preston Place, there were no draft stops in the attic or ceiling spaces separating units. The fire was able to use these connected spaces as fire highways to spread.
A fire block is sorta the same as a draft stop except it’s for shared and exterior walls. Installing walls rated to withstand fire for a certain number of hours (two hours, four hours, etc.) keep fire from immediately moving to a neighboring unit. This gives residents time to escape and firefighters time to quell a blaze. Fire blocks are also the installation of horizontal cross-beams between vertical studs inside a wall during construction. The whole point is to eliminate fire highways inside floors, ceilings, and between rooms and units.
Chief Price said that while Preston Place had some fire blocks, they weren’t as prevalent as in a structure built today. He also said that while fire blocks are rated for a number of hours, that’s only a guide, not a guarantee. Depending on how hot the fire is burning (something that has a number of variables) and the pressure of the fire, they can fail faster or slower.
He also noted that over the years, fire blocks and draft stops may have become compromised. It’s fairly common for the installers of new electric, plumbing, TV, internet, or updated utilities of any sort to have poked holes to run the lines or facilitated the installer’s movement around attics and crawlspaces that were previously sealed by a stop or block. This is something all property owners need to check and repair if they’ve been damaged.
Fire blocks are now also used to protect stairwells from fire intrusion longer to facilitate egress but also to protect firefighter access. High-rises take an added step with air-pressurized stairwells to keep smoke out (along with concrete encased stairwells).
Both Laurel buildings are utilizing both draft stops and fire blocks to contain units and stairwells. Additionally, because of the south building’s larger size, it’s been divided into three sections further separated by automatically-closing fire doors.
Indoor Fire Hydrants for Fire Protection
Water is obviously a critical component of firefighting. Chief Price said the Preston Place blaze involved some 170 firefighters who were running hoses as far as 2,500 feet away — that’s nearly half a mile!
While Preston Place wasn’t required to install what are known as “dry standpipes” all those years ago, new construction is. What’s a dry standpipe? It’s a non-pressurized water outlet for connecting fire hoses that’s located on property. In multi-family, they’d be located on a building’s exterior and in hallways. This brings water closer to the fire, increasing effectiveness and reducing the need to pull water from so far away.
The Laurel will have dry standpipes.
Flame Retardant Building Materials
Back in the olden days, asbestos was all the rage as a fire retardant. It was cheap and did the job. It may surprise you to know that the first health studies proving asbestos’ danger were conducted in 1900, and yet it took the world decades to curtail its use. Heck, back then the fake snow seen in movies and sold to toss around the house at Christmas was asbestos.
Preston Place was built on the eve of the explosion of asbestos litigation in the U.S. that would severely curtail usage. Therefore it’s probable there was asbestos in the building. However, there is good news for those downwind of the fire. At a certain temperature, asbestos melts to become glass, decreasing the potential for mobility and ultimately inhalation.
You may be surprised to know that unlike over 50 countries worldwide, the U.S. has not outright banned asbestos, merely curtailed its use, even after a century of health data, nearly 1 million litigants and $37 billion in settlements. Thankfully, the Laurel project will contain no asbestos.
Since Preston Place was built in 1979, safer fire retardants have been in use in various construction materials including insulation, exterior sheathing, and lumber. The Laurel will be using these materials where called for.
In construction, the march of time makes us safer. While rarely figured into arguments for or against development, the safety offered by newer structures is a quantifiable advantage that should be taken into account.
Remember: High-rises, HOAs, and renovation are my beat. But I also appreciate modern and historical architecture balanced against the YIMBY movement. If you’re interested in hosting a Candysdirt.com Staff Meeting event, I’m your guy. In 2016, my writing was recognized with Bronze and Silver awards from the National Association of Real Estate Editors. Have a story to tell or a marriage proposal to make? Shoot me an email firstname.lastname@example.org.