any architect or contractors??? Header Help

Bearing wall?

82 inches, I'd use double 2x12s. Seriously.

 

2 x 6 Header is fine. Even less if no building inspector is expected.

 

Architect? they draw pretty buildings, then engineers have to figure out how to stop them falling down.

Simple enough calculation: figure 100 pounds per square foot of loft, plus 100 pounds per square foot of roof, to get the total load on your walls. Divide that by the total length of the load-bearing walls (to be on the safe side I'd call the "A" walls non-load bearing.) Now you have a load in pounds per foot. Multiply by 7 to get the load on that header. Once you've done that you can figure what size to make it. Or post your calcs here and I'll take a stab at it.

Don't forget that the posts on either side of that header have to take all that extra weight too, so plan to beef them up, and brace them. Columns fail by buckling.

 

Not really. I do my own engineering. To the original poster, how long are the bearing members from the second floor? Let me know and I'll run you a beamcheck data page that will accurately size the header. Also, what grade of wood will you use? SYP or DF/L #2? If you don't know, where in the country will this be installed? As a guess I would say double 2x8 will be sufficient, but more info needed.
BT

 

So its a regular 2x4 frammed wall with a double top sill of 2x4's, 8' high??

Personally, I'd go with the largest dimension you can get in there. If the wall is 8' high, the french door must be 6'-8" leaving a rough opening of 82"x82"? That leaves you with 14" from the top of the RO to the bottom of the doubled up 2x4 top sills.

If you are cramped for space (wires, etc, ?) I'd try to at least get (2) 7-1/4" LVL's nailed and glued in there. Similar would be (2) 2x8" dimensional lumber with a section of 3/4" plywood sandwiched in between nailed and glued.

If you are not cramped for space go as big as you can (2) 11-7/8" LVL,s, or (2) 2x12's with the 3/4' ply...sure, that's overkill, but you dont want to ever have to go back in and fix it do you?

If you have the access, why not do it so you don't have to worry about it.

 

That's the way I'd do it - you're talking about $75 out the door for a pre-nailed/glued double LVL cut to your spec. Well worth it for peace of mind!

 

Exactly. I bet the price difference in using 2x8 vs 2x12 would be less than 10 bucks.

Addendum. I checked, the price difference for 2 of each is $4.00 total.

 

you are probably right, but my framing experience comes largely from work on my own home where you are lucky to be able to sqeeze in a couple of 2x4 and still have any head room.

 

the rule of thumb for headers is 4X4 material up to 4 feet, 4X6 up to 6 feet and 4X8 up to 8 feet in width and so forth usually this covers most cases with some overkill for live and dead loads in most seismic zones including zone 4. the preferred lumber in load bearing walls should be struc1 DF perhaps best in KD form.

good luck

 

2-2x6 = (roof only load) 4'-6' span: (one story load) 4' span
2-2x8 = (roof only load) 6'-8' span: (one story load) 4'-6' span
2-2x10 = (roof only load) 8'-10' span: (one story load) 6'-8' span: (two story load) 4'-6' span
2-2x12 = (roof only load) 10'-12' span: (one story load) 8'-10' span: (two story load) 6'-8' span

if you're using the upper loft area above for live loads i'd err to the 2nd story load approach. and use 2-2x12's