Before my wife and I bought our house on Adams Street, we sat down with our brother-in-law and contractor- to-be, Scott Day, to discuss a barebones budget. (Please see last month's column in which I discussed the futility of good budgeting during a renovation project). One of the items that Scott thought we should include in our budget was labor and material for fireblocking. Laura asked for an explanation, and Scott gave her one, and I nodded knowingly, not admitting that my mental image of fireblocking was rather fuzzy. When he added that our house needed fireblocking because the walls were almost certainly balloon-frame construction, I said, "Of course," and began to get nervous. I'd never heard of balloon-frame construction, but it sounded neither solid nor fire resistant. Laura was enthusiastic about every single fire prevention measure that Scott could think of, so we agreed that we needed to include fireblocking in our renovation plan. And to my surprise, I soon became obsessed with effective fireblocking.


Even if you've never heard of fireblocking, you've certainly seen it when you've looked at a new house (or the King William TownHomes) being framed. Picture first a deck (floor), then 8-foot or maybe 10-foot walls, then another deck, then more walls, then the roof. And all those little spacer blocks of 2x4 between the studs? That's fireblocking. Building codes require those blocks of wood every 10' vertically in all concealed spaces. Most carpenters put them between studs about midway up the wall or lower because it's convenient to put them there.

Our house, like probably most of the older two-story wood-frame houses in the area, was built very differently. At the end of the 19th century, when southern forests still had some wondrously tall, straight, oldgrowth pine trees, builders could buy 2x4 studs that were some 26 feet long. In these old balloon-frame houses, tremendously long studs run from foundation to attic, with no fireblocking between them. The second floor was hung on the exterior walls the way a closet shelf might sit on a little board nailed to the wall. Obviously, any fire that gets in these walls downstairs has a direct path up and into the spaces between the floor joists of the second story as well as up to the attic. With nothing to block it or even slow it down, fire would spread like, well, wildfire.

And incidentally, any critters that get in these walls can roam freely, too. In my house, when we opened the walls to add fireblocking or for other reasons, we found signs of previous critter infestation everywhere. Critters big and small. Above windows. Above doorways. It was some kind of zoological park in our walls. While blocking an actual fire might never occur, stopping critters is a very real function of our fireblocking. Hence my obsession to add it to even the smallest of concealed spaces in the walls throughout the house.

Which brings me back to a point I made in last month's piece. You only get one chance to do certain things right in renovating these older houses. Before the sheetrock is up, while the walls are being opened up for plumbers and electricians-this is the time to peel off one course of shiplap in every room, custom cut the 2x4 blocks, secure them between the studs throughout the house, and then reinstall the shiplap. And how much did we spend on wood and fasteners for all of our fireblocking? It's hard to say. Not that much. How long did it take? I don't really know specifically how long it took. It did seem like a long time. But a good night's sleep now that we are in our critter- and fire-resistant house? That's priceless.

John Hartman