Townhome Firewalls (apartment, condo, townhouse)

[Smokipenelope]

Hi -

Does anyone have any thoughts or advice on townhome firewalls? I'm considering a few communities in Brookhaven (all new construction) - and they have all told me their firewalls are two inches thick and provide two hours of protection - and are drywall. They all say this is code for Dekalb County, and also say they extend up into the attic and then lie flat against the roof (they don't go up through it). When I looked at townhomes in Gwinnett County I remember firewalls as being concrete and lasting anywhere from 4- 8 hours, plus they stuck up through the roof. Would appreciate thoughts/comments on this drywall 2 hour firewall and if it really is standard and decent. The realtors I've talked to all seem to think I'm crazy for caring so much but I'd rather be safe than sorry, especially for such a big investment (300's).

Thank you!

[BobKovacs]

As you've heard, conventional townhome construction nowadays is a 2-hour separation wall construction of gypsum board. IMO, anything more than that isn't really necessary, considering that if a fire is raging in a townhouse for more than about 45 minutes, the entire structure of that unit has collapsed, and the firemen likely have the fire under control or out at that point. In the process of putting out the fire, they've likely destroyed your adjacent unit with water and/or smoke damage anyway, so having a longer-rated wall is really a moot point.

You're highly unlikely to find anything new with more than a 2-hour rating, so unless you want to go into one of the much older units with the 4-hour CMU walls through the roof (which probably aren't going to last for 4 hours anyway), you're pretty much out of luck anyway. No builder is going to spend the money to construct a 4-hour wall when the code will allow him to build with a much less expensive 2-hour assembly.

[scgraham]

A 2-hour firewall seems to be adequate, insomuch as it meets county requirements. With that said, let you private home inspector give you guidance in this area.

Is that 2 inches thick on both sides?

[BobKovacs]

Originally Posted by scgraham

A 2-hour firewall seems to be adequate, insomuch as it meets county requirements. With that said, let you private home inspector give you guidance in this area.

Is that 2 inches thick on both sides?

The assembly is a 2" piece of gypsum shaftwall material that's clipped between two framed walls (one in either unit), which each receive insulation and drywall to create the finished wall surface in the townhouse/condo. The clips are made to melt during a fire, which allows the wall in the unit that's involved in the fire to fall away without taking down the 2" shaftwall, thus keeping the fire rating intact.

[atlantagreg30127]

I dunno, I think Bob knows his stuff, but in this case "if it were me" I'd still be more comfortable with concrete firewalls. Again, that's just me, and I realize building standards today aren't what they used to be.

This actually took place in Brookhaven, ironically: Back in the 80s, I lived in a complex called "4120 Peachtree" which was across the street from the Brookhaven MARTA station (today a Post Property sits on that land). These were 1940s-built 2 story brick townhomes with solid concrete firewalls in-between each unit.

One day I came home to see smoke and fire POURING out of the end of my building. The end unit was engulfed and surrounded by firetrucks. My apartment was the third one from the end. According to neighbors, it had been raging for a long time. Eventually it was under control, but that particular unit was a complete loss. Well, I can tell you this... aside from a medium-strong smell of smoke, the unit NEXT DOOR was fully intact and suffered no major damage. My unit two over only had a small smell of smoke and I was able to go back into my place within hours.

I dare to say that I just don't see that type of scenerio playing out so well with gypsum board. Now, there is a fireproof paint like coating that was really raved about on a number of home shows a while back called "Contego" (link HERE for it). Apparently, you can "paint" this stuff on wood or other objects and it just about makes them completely fireproof if done right. I suppose if they used gypsum board and coated it with that stuff, it would add an extra layer of protection that would help, so long as it was done right during the construction phase. My guess is unless you watch the contractor actually do it per your request, they don't bother with that type of expense.

[Smokipenelope]

Thank you very much, this has all been very helpful!

I'm hoping to get an end unit so I'd only be connected on the one side. Plus I've heard its hard to resell an interior unit, so I'm really trying to stay away from those.

[atlantagreg30127]

Originally Posted by Smokipenelope

Thank you very much, this has all been very helpful!

I'm hoping to get an end unit so I'd only be connected on the one side. Plus I've heard its hard to resell an interior unit, so I'm really trying to stay away from those.

My experience from knowing realtors and just observation, is that yes, end units are highly sought after - especially if they have a finished basement with a bathroom (people use those as offices, in-law suites, or teen suites). They also tend to cost more than mid-building units, and sell more quickly.