form bond beam - Contractor Talk - Professional Construction and Remodeling Forum

bobbrown · 09-10-2006, 08:15 AM

need to pour a bond beam with maximum unsupported span of about 16 feet. no problem with the forming or bar. fretting over the size and number of supports necessary to support the forms.
this is a 8 x 14 inch beam 12 feet in the air and forms the top of rough masonary opening for a window bank.
thanks
bob brown

mdshunk · 09-10-2006, 08:27 AM

I read bond beam, but it sounds more like an lintel.

I have the weight of the wet concrete (14 cubic feet) calculated at 2310 pounds plus the weight of 1-#7 and 2#5 rebars at 50.06 pounds. You'll be at about 2,260 pounds up in the air. That's 141 pounds per foot. That's all I got.

K2 · 09-10-2006, 08:39 AM

My rule for concrete forming is what you think will hold x 3. Your bond beam is not really very heavy. In my area they make and use bond beam blocks for the same header/lintle application. A wood framed support is still required.

stacker · 09-10-2006, 10:11 AM

i would either make a rough buck,and lay a row of knock out,solid bottom bond beams.
well after reading your post again i would use a horse shoe lintil block cut to 14 in.it will measure 8x8x16 open on the end(looks like a horse shoe)hence the name.lay it like a solider.place two number 5 rebar in it(on toward the bottom and on at the top.and pour with grout.make sure you extend at least 8 in on both sides of the window.

bobbrown · 09-10-2006, 02:03 PM

well, the beam has to poured in place. so, i'm thinking 2x10 ripped down to the 8 inches (typical 8" wall block off) along the bottom.
could double up if you think necessary. supports on each end attached to side columns. then....span supports. could do side by side 2x4 or (what ever)at (what ever) on center.,...can anyone fill in the what ever's for me.
thanks
bob

stacker · 09-10-2006, 03:50 PM

i dont understand what you are doing i guess.if you have a block wall already and you are pouring a beam across this window,you might as well do as we suggested.the only forming you would need to do is a rough buck in the window opening.your bond beam block or lintil block would then serve as you form for the beam.support on the sides with a 2x8 and 3-4 2x8 supports thru the window should do it.

Nac · 09-10-2006, 04:15 PM

I think what he is saying he has to pour a lintel in place not a bond beam. So just get a 2x8 and 2 2x12 and build your form put some scrap lumber acroos the top of the form to keep it from pulling apart. set 1 leg on each side of opening and maybee a 2x6 post about 3' apart in the middle. or you can just pour it on the ground and set it after the concrete cure like a normal lintel.

Tscarborough · 09-10-2006, 09:19 PM

It is the job of an engineer to determine the proper size and reinforcing. If you have that information and are just looking for the proper method to shore it, then form it as you think should work, and then double your shoring and strongbacks and you will be fine.

bobbrown · 09-11-2006, 06:54 AM

thanks guys. appreciate the help
lintel is the correct discription of the project