Remove load bearing wall – blind beam
I’m gettting ready to remodel a kitchen in a pretty basic ranch and am in the planning phases. Load bearing wall running down the center of the house supported by 3 2×10 built up beam in basement. There’s an existing 60″ opening in this wall at the start of the kitchen supported by a blind beam in the attic that’s a 70″ pair of 2×8’s setting on top of and attached to 4 ceiling joists. The beam in the basement is supported by 3 screw type posts on footings approx 90″ on center. I’d like to expand this opening by about 60″ for a total of 120″. Would like to keep it a blind beam and am only expanding in one direction. The side staying the same is approx centered on one of the basement posts. The side expanding at the moment is approx 26″ to the left of a basement post which would push the new location 34″ to the right of post. Looking like triple 12′ 2×12’s should be adequate for the new blind beam. The bulk of this beam is going to be supported by 2 posts and at the very least I’m planning on placing a new screw post under the basement beam at the point the new post will be… or should I expect to have to dig a footing under that post as well? Any diagrams or descriptions of the best way to frame a blind beam? Still am thinking about a more decorative 6×6 post and partial beam that would keep the existing blind beam. Any thoughts would be appreciated.
Replies
What is the blind beam in the attic supporting? The roof? If so, what is the rafter situation?
Let's start there, but in the meantime I'll say that you should definitely plan to add footings under whatever new post locations you decide to use. Your basement slab is not meant to handle these point loads, though it is mistakenly done quite often, and mostly results in some nasty cracks but I'll bet others here have seen things get more ugly.
Just a simple common rafter / no bracing. Both rafters and ceiling joists are 2x6. House is 25' wide with the beam roughly centered under the ridge. As far as I can tell the beam is just carrying four ceiling joists. The 58" headerless opening that I want to expand is in the load bearing wall running down the center of the house with visible headers in all other openings supporting the overlapping ceiling joists. As it is now there is no post in the basement directly under one side of the beam/post and I'm moving the new post about the same distance off to the other side - though it will be carrying more weight.
The beam now is sitting on top of the existing ceiling joists with a scrap 2x6 in between the beam and top plate. 2x4 braces attached to the beam and joist one side only are the only visible connection between the beam and joists. Typical or is there a better way to frame the new beam?
Thanks for the reply
Edited 3/22/2005 7:06 pm ET by Hobbesy
As you said, it's only carrying the ceiling, the cantilever should be no problem
Hobbesy,
Can you clarify something for me?
Is this sketch what you have?
Where is this 2x4 brace?
Can you post pictures?
View Image
SamT
Exactly. Was having trouble describing this - the 2x4s are actually the hangers connecting the joists to the beams not braces. Was just searching to see if I could find a double joist hanger tall enough to do the same thing.
Thanks for going to all the trouble! Pictures attached
Yeah, that's how I read your original post. I was trying to see if there was anything additional being supported by the header beam, but basically all the bearing wall is holding up is your ceiling, joists, insulation, mechanicals, lights, etc.Not a really big load. I'm not an engineer but it sure seems like you could just use joist hangers with an LVL header suggested by a previous poster. Just need to provide temporary support of the ceilings on both sides of the new beam area.
Sorry, replied to the wrong poster...but to Hobbsy....
Basically this beam is only suporting dead loads (ceiling joists, insulation, drywall, and its own weight). The jack studs are currently 26" away from a post below. The proposed location would move the jacks 34" further. If I understood the layout, the posts are 90" OC. The proposed jack studs would then be 30" to the left of the next post or support (?)...
So your new opening configuration would not be considerably different than your current situation. The dead load on the jack studs would increase due to the increased amount of ceiling being supported, but it is not drastically larger..
So in essence, what you are proposing to do should be acceptable. Check the Simpson Strong-Tie website for joist hangers. I would tend to believe they make a hanger for your application...
Edited 3/23/2005 8:40 am ET by MJLONIGRO
Hobbesy,
I took the time to mark up one of your pics with some terminology, so we would all be on the same page. See attachment.
To clarify, you have NO rafters and NO braces.
Your main floor bearing wall with the opening in it is only bearing the ceiling, a relatively light load.
You have a one story with basement structure.
The main beam, in the basement, has three screw jacks as columns, evenly spaced along its length. The columns are sitting on footings. The main beam is somewhere around 24' long.
Azz-You-Me-ing I have all the relevant facts, here's what I would do;
Phase 1. Stringline the main beam, adjust the screwjacks to straighten it out. replace the screwjacks with (structural engineer checked) 6x6 wood columns. Sister a fourth 2x10 (acclimatized) to the beam. Butt the center ends over a column, and don't worry about supporting the ends next to the outer walls.
Phase 2. Build 2, (2x4, 2' OC,) temporary bearing walls under the main ceiling the length of the planned opening, 2' on each side of the main bearing wall, with double top and bottom plates.
Phase 3. Demo the bearing wall for the opening. Demo the existing hidden header and those stupid hanger blocks.
Phase 4. frame the new opening with a double 2x10 Blind Header, proper Simpson hangers for the ceiling joists, 2 Jack Studs, a King Stud, and a Trimmer Stud on each end. Add bearing blocks on top of the main beam in the basement directly under each end of the Blind Header. Add two knee braces, one on each side, at each end of the Blind Header, running diagonally from the top of the Blind Header out to a ceiling joist.
(High quality, High Definition ASCII drawing follows.)
//|| Knee Braces ------------
Phase 5 & 6. Cleanup and finish.
SamT
"Phase 2. Build 2, (2x4, 2' OC,) temporary bearing walls under the main ceiling the length of the planned opening, 2' on each side of the main bearing wall, with double top and bottom plates."Why? He already had support there that is not in the way.What about this order. Install new king studs.Install temp support in the old doorway area.Remove existing beam.Install new beam and hangers.Then demo the wall.
Well I think I've got a handle on it. As easy as it usually is to find info on the web I could not find a single diagram of a blind header to compare to mine. Knew those hanger blocks looked hokie though:) Found a double face mount hanger with 23" legs that I'll be able to wrap up and over the top of the header.
Would you tear out the top plate so the king stud and trimmer can actually hit the bottom of the header or are a couple short jack studs (blocks) between the header and top plate supported by the king/trimmer below going to accomplish the same thing?
Appreciate your, and everyone else, taking the time to mess with this
Edited 3/23/2005 6:58 pm ET by Hobbesy
Hobbesy,
Check out Bill's post, 55896.14, also Tharrett's 55896.12.
My bad, of course you do it with blocks over the plates. No King Studs, just jacks and trimmers.
SamT
Took a weeks vacation and dove into the project. Thought I'd post a picture of the finished beam:) Also a before and after (nowhere close to being finished but I've gotten the biggest chunk of the structural work done) of what I'm trying to do with the space. There's a stairway between the kitchen and living room and the kitchen was completely cut of from the rest of the house. Trying to open up the space and get the effect of an island / breakfast bar when finished. Wasn't planning on keeping that cubby hole beneath the bar - which was part of the existing closet - but I think when it's drywalled and trimmed it could turn out really interesting. The counter on the raised section is just a mock up done with some of the flooring I pulled up from the kitchen so my wife could decide how much overhang she wants on the living room side. The lower section will have 12" overhang front and left which will be just past where the stop on that jamb is now.
Looks done to me. All you need now is a bottle of Black Seal, some ginger beer, ice and a lime.Glad it's going well,Dog
I believe if you switch that (3) 2x12 to a micro lam (double 11 7/8) you could carry that ceiling by headering the micro into doubled cieling joists, essentially cantilevering from the post that is existing to the double joist.
just did a job like this .. used an LVL 3 1/2 X 12, had option of 2 thinner ones, but single beam was easier to handle and less "wonky" installing .. Simpson strong tie makes hangers for this type of application http://www.strongtie.com/products/connectors_list/THAI.html, they are pricey ($25 each) but inspectors won't sign off on anything that won't cya them .. the hanger will have to be wide enough to take 2-3 cieling joists depending if they are offset or not, you can get away with only 1 per cieling joist pair (4000 lb) each when fully nailed. My new opening landed 12 " from an existing steel column in the basement, still had to put in a new jack post and footing, the size of the footing will depend on the soil under your slab, the new footing had to be 2 ft square, 14" deep .. you got it .. 4 times the size of the one under the existing column a foot away .. good luck
It does not sound like you have a whole lot of load here, just the dead lot of the ceiling... If you are worried about the point load not being over the screw jacks, here is another option.
Lengthen your blind beam such that is ends over the next screw jack (maybe another 6 feet longer) and then resize the blind beam accordingly. Basically extra material in the attic, eliminating the possible need for an extra post and footing in the basement...
Whem you figure out what you're gonna do you might want to price check a glulam structural grade beam. I was surprised to learn a few years ago they are cheaper (at least here in the Pacific Northwest) than LVL beams of comparable strength. Might vary, with location, I don't know.Free speech leads to a free society.