Expert: Stephen Major (Owner--Major Design Group) - 5/29/2007

Question
Hi Stephen,

I would like to put an opening, +/- w.7' x h.81", through an existing wall to link two rooms.  One of the rooms is an addition to the original house, so the opening is in a load-bearing, formerly exterior wall.  It's an outside wall of 2x4 studs about 16" apart and does have the 1x6 diagonals on the outside(not sure about inside), and has wallboard on both sides since the addition.  

The hole we want to make will probably be 7'long (the wall is 13') and 80" high--or whatever the other doors in the house are.  It won't have an actual door, just an opening from one room to the next.  I like the idea of the big lintel overlapping the verticals and maybe showing through the plaster.

The two things I'm wondering about are (1) the bracing, so the building doesn't collapse on my head (or saw), and (2) how to jam that lintel up there so it's tight against the verticals going up from it through the ceiling? It's a two-story house.  I guess if you could direct me to a table to determine the size of the lintel, that would also be a great help.

Thank you,

Laurie

Answer
Laurie,

I'm missing a number of critical pieces of information, but I'll give this my best shot.  If at all possible, please send a photo of the wall (opened up, studs all exposed) to my e-mail:
info@majordesigngroup.com   

Prior to cutting out bearing studs you need to temporarily support the loads coming down from above.  Your goal is to make those cuts with zero sag or settling occurring.  How you brace the wall depends on its construction and the direction and intersection of the 2nd floor joists.  If the joists are perpendicular to the wall (i.e. bearing on it) then its a pretty simple matter to construct a temporary wall about 12 to 24 inches back from the wall which is to be cut.  

Otherwise you may need to construct a series of diagonal braces anchored securely to the upper wall and the floor.  If I could see the area I could advise with more detail.  In any case do not attempt this unless you are very sure of what you are doing.

Once the loads are temporarily transferred, make your opening.  Install the header (lintel) in place using a jack on each end.  Brace the header well, and have plenty of help.  These things can kick out and fall suddenly while going in.  Install a king stud and two jack (bearing) studs on each end, all spiked together.  For typical loads (floor plus roof) you would need at least a doubled 2x12 as a header.  BUT without knowing the loads this is a calculation that needs to be done by someone with structural knowledge and who has seen the site conditions.  You may even need to use laminated veneer lumber (LVL) if the loads call for it.  

Also, be very sure that the new point loads (at each end of the opening) are solidly transferred to the foundation.  This is usually accomplished by precisely inserting vertical blocking in the joist cavity below.

When doing structural surgery it is highly advisable to have a qualified engineer or architect advise you on the precise methods.

Best of luck, and send those photos if you are able.  Let me know if you have additional questions.

--Steve Major