Firewall House Design

Rafael, who lives in Fort Myers  FL, is wondering about firewalls. Here's what he sent me.

"A house built in 1970 has no fire wall. In what year were firewalls installed in the new homes?"

Well, Rafael, I find it hard to believe that a 1970's house has no firewall.

I say that because typical construction of both exterior and interior walls consists of vertical studs capped by continuous top and bottom plates.

You can get into serious issues with respect to firestopping if you then add a soffit at the top of a wall.

Soffits require lots of added blocking to ensure they're firestopped.

The earliest firewalls and fire blocking I'm aware of started in the late 1800's.

I remodeled quite a few homes built in that time period that had dangerous balloon framing.

In many of these houses, I ran into 2x4 blocks put in between the studs that acted as very good fire stops.