Removing a bearing wall

[tbent]

I have a 21x16 addition. The attic is a 2x4 rafter system with 2x6 floor j's that are centered on a 16' bearing wall below. It runs parallel with the peak. We want to make one large room instead of two smaller ones below the attic (first floor) and have bared all of the first floor's area back, and have installed two 2x4 temp walls, one on either side of the bearing wall. They are 24" out each side, with the bottom plate centered and screwed into the first floor's j's. They are cross screwed through the top plate into each of the attic's floor j's. We are planning to open up the attic floor above the bearing wall, cut out the overlapping of the j's to accommidate the beam and ease it down onto the vertical beams in the 2 end walls, finishing it off with hangers on each j to the beam.

My concern is with the horizontal movement of the attic's floor j's. Does the horizontal movement happen over time? Is the few days it'll be cut out be ok? Or should I use stretchers from one temp 2x4 wall as high up as possible to the other temp wall to stop any horizontal movement the 2x6's will naturally want to do? Any other ideas or concerns?

[Don_P]

Install a correctly sized beam under the ridge and support each end. If the ridge cannot sink there is no thrust and no structural need for ceiling joists. The existing ceiling joists can be hung from the ridge beam if you want to.

To give the short answer if you support the existing rige board with angled posts from floor to ridge at several places that will keep things from spreading.

[tbent]

:( I'd love to do that. The problem is that our rafters are plumb-cut and nailed at the peak. Sorry, no ridge beam in either part of the house. There are stretchers 2' below the peak, but they are only 1x4's and with the attic rafter bays recently deepened and foam-insulated for drywalling this coming Winter, access to the peak isn't a good option. (the 1st section of the house was built about 1949, originally as a 24Lx20w Cape Cod style. In 1953, the addition I'm working on was extended 16' longer to a make a 40Lx20w.)

[Don_P]

If you can have the beam sitting on the attic floor up there, then run temporary ceiling joists about every 4', nailed to the rafters on opposing sides, above the beam by an inch or two. They will restrain the roof from spreading while you cut the joists. Don't skimp on the nails holding the temporary ties. If the roof is "soft" it may well try to spread. Pay attention to the gaps in your previous cuts as you proceed. Lifting or holding up the ridge pulls the walls back together, might not be a pleasant option but that's the way it works if you get into spreading trouble. In reality at this size unless its in real rough shape or the roof is very heavy this really shouldn't spread. You will need to strap across, joist to joist, across the beam when you're done or center a well nailed sheet of ply across the beam to retie the joists across from rafter to rafter. Some framing angles to connect the rafters to the wall plates wouldn't hurt if you have access to that area.

[tbent]

I'd like to repeat this back to you to be sure I have this correct. 1) prepare the beam and ready it near the insertion point 2) Just above the beam, every 4' of the 16' width of the room, use a 2x4 to span from one rafter to it's mate on the other side and nail it off well at each end. 3) prepare for and then remove the bearing wall and cut the floor joists at the overlap to fit the beam , monitoring each of the gaps created. If there is any movement, post and beam the peak to pull it back and prevent further sreading.

(It seems to be a light roof- one layer of 10 year old 3-tab shingles, one layer of tar-paper, and 50 yr.old 3/4x 8" tongue and groove "barn board" on 2x4 rafters on an 8:12 pitch. Inside, on the upper half of the length of each 2x4 rafter, we face screwed light 18 guage steel framing to provide a straight drywall surface for later and to deepen the rafter wells for the 1/2 lb per sq.ft. spray foam insulation at 5 1/2 inches deep, which has been already installed.)

4) Install posts and then the beam. 5)Use straps across the top of the beam from the top of one joist to the other. (we have retrofitted hurricane clips at the rafter ends tying them to the top plate at every rafter.)

Did I get everything?

[Don_P]

Yup, sounds like we're on the same page.

[tbent]

Just a final note. The 16 ' 2x10 w 1/2" ply sandwiched inbetween-beam is up and looking very good. We had no deflection and no lateral movement. When I went to drop the beam from above, the cuts were tight, so a bar of soap on the contact points of the joists and beam was all it took. Incidentally, with the nailing of those 24 hangers x 8- 16's apiece, I invested in a palm nailer and what a delight! About 1 1/4 hours and no effort. Highly recommend trying one. Thanks for all the assistance.