Headerless Wall Openings
Get excess wood out of the walls - skip headers where they are unnecessary and use rim joist headers where they are.
There are lots of elements to high performance homebuilding we’re incorporating on this project. I try to remove every piece of wood from the walls as possible and leave the space for insulation.
Often half of the openings in a typical house don’t need structural headers. And those openings that do need headers can benefit from alternative framing methods to minimize thermal bridging.
Most window and door openings don’t need typical headers resting on jack studs. Non-bearing wall openings less than 8 ft. wide don’t need any header. So on the gable ends of this house, we just installed king studs and a flat head board.
Bearing walls are framed the same way – king studs and a flat head board. So how are the loads transferred from the floor and roof above? The rim joist. For narrow openings – like single windows- the rim joist itself is usually strong enough to carry the load around the opening. We followed the 2015 IRC prescriptive measures for rim joist header design and made sure there were no joints within the opening area nor within 6 in. to either side of the king studs.
On wider openings like mulled windows and patio doors we ran the rim joist continuously over the opening and added an LVL on the inside of the rim joist – essentially building a 2-ply header in the floor system. On this project the engineer specified the header/rim joist requirements for each opening as well as the number of king studs.
Wherever joists land at openings we’ll install a joist hanger mounted to the rim joist or the LVL.