Draft Stop Floor Framing Detail

The uniform building code 2009 ed defines a draft stop as a material device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces floor ceiling assemblies roof ceiling assemblies and attics.

Draft stop floor framing detail.

Draft stop between floors. This will allow the draft stop company to seal up all holes and gaps created while running mechanicals through the walls. Details for conventional wood frame construction. Wood construction data 1.

When framing soffits or columns that will have drywall installed on them or any other architectural feature like an arch it seems that fire blocking is necessary because there is almost always a cavity on the top side that goes up into the ceiling or floor above. Insulation is not an issue. Draft stopping shall divide the concealed space into approximately equal areas. Ive always been called on and been under the impression from reading the code book that all floor ceiling and attic penetrations have to be draft stopped.

Scraps of lumber plywood and gypsum board are commonly used as fireblocking and draftstopping and something as simple as strips of 1 2 inch thick drywall fastened to the side of floor framing members and tight to the top of the ceiling membrane will typically suffice. The irc r502 12 states when there is usable space both above and below the concealed space of a floor ceiling assembly draft stops shall be installed so that the area of the concealed space does not exceed 1 000 square feet. This is a draft stop required to divide the mid floor when open web trusses are used so no area is greater than 1000 square feet. So today i had a super pull me into a conversation between the hvac sub and himself about a draft stop.

Floor framing is constructed of truss type open web or perforated members. The area was an hvac chase that runs from first floor deck to second floor joist. You will want to hold off on the draft stop activity until all drilling and cutting in the walls are complete. So basically all plumbing electrical and ductwork rough ins should be 100 percent complete.

These passage ways are sometimes hard to see when the drywall is not yet installed. Such methods use a 4 foot design module which governs a 16 inch spacing of joists.