What is a fire stop? Does this go into the stud wall to prevent (or slow) the spread of fire to the first floor. If so, how are they constructed or can they be purchased for installation?

 

A fire stop is something, usually wood, inserted between the studs in a wall, to keep a fire from racing upward inside of a wall. The most common are lengths of 2x4's (providing you have 2x4 studs) cut to length and nailed or screwed between the studs usually about 18 inches down from the ceiling. They are uauslly installed when a wall is built. However on a remodel of a home for an apartment home, the wall board would have to be taken off in order to install them.

 

Firestops can be made of solid wood, of drywall, or of fiberglass insulation.

There are basically two kinds: horizontal firestops (slows the spread of fire horizontally behind the wall) and vertical firestops (slows the spread of fire up into the joists). Most codes require horizontal firestops every 10 feet along the wall, extending tightly back to the foundation wall. Vertical firestops are normally continuous and prevent the spread of fire from behind the wall up into the joist cavity. Vertical firestops are also required along the side of your staircase to slow a fire under the stairs from rising to the stairs themselves.

If you're finishing a basement, you may be able to do the framing and then have the inspector come out and he'll tell you where you need more firestop. Ask your inspector.

 

If you use drywall, which you can make sure it is 90 minute rated. Special sheetrock and more expensive.

 

My city allows ordinary 1/2" drywall. Check with your local building department. As Jack indicates, it varies.

 

Hello
Keep in mind for a fire stop to work it must have sheetrock on both sides or exterior siding/stucco on the outside to work..