I have to bid on cutting a 9feet by 9feet opening for garage door. The wall is 12''block 24courses high. Should I cut a hole above where the opening is and put a I beam to hold the wall while I cut the opening for garage door.:thumbsup:
WRer
You will need to install a solid concrete lintel consting of 3 4x8x10' in place of one course of your block. It looks like your wall is 24 x 8= 16 ft tall. That will leave about 7 ft above the door opening. If it were me, I'd do it in stages. First remove enough of the block to allow 1 lintil to be installed. This will require busting out 1/2 of the lintel course. Then install the one lintel, & let set a few days. Then finish removing the rest of the lintel courses, & install the other two lintels. After that, I'd cut the opening out.
Joe
Joe
You should have some engineered drawings for this. Is the block poured solid?
How long is the wall and what is the load on top? You will be removing over 50% of wall for 9' or so in width. That is potentially a pretty good chunk of lateral stability gone. You will definitely need a lintel and also some direction how to attach it to the wall. An engineer would be able to provide these details and what ever else is required to keep the integrity of the wall intact.
How long is the wall and what is the load on top? You will be removing over 50% of wall for 9' or so in width. That is potentially a pretty good chunk of lateral stability gone. You will definitely need a lintel and also some direction how to attach it to the wall. An engineer would be able to provide these details and what ever else is required to keep the integrity of the wall intact.
you will need to needle the wall and use angle iron for shure...would definitly have a archetech involved to cover your ass...this sorta thing is almost a trade in itself and being your dealing with 12 in block as well will be even more issue re wieght..lota things to be worked out here with the lintle being the main issue..how do you plan on doing that...
chances are this wall isnt full ..if so would make things easyer but cant see it
chances are this wall isnt full ..if so would make things easyer but cant see it
That is sure to be a pain even with proper engineering. I recall once we had to remove 4 inch brick from the lower 10' of a 2 story wall and insert a beam. Took twice as long as we thought and was definitely not fun. I wonder if they will have you prop up the roof load seperately from the weight of the block? At least that way if you fail you only lose the wall and not the roof too.
My shop has 12" concrete block, with 10 x 12 gar doors. The ceiling ht is well over 19', which means there is over 7' above each dr opening . It has three 4x8 concrete lintels at the doors. The previous occupant had one of the lintels trashed by trucks raming the loading dock. We had to replace the outer one. If you install the lintel before cutting the opening out, you shoudn't have any problem.
Joe
Joe
You should be talking to an architect, not asking in here what you should do or not to do. This site is for professional contractors, not HO. You should also get a permit to do this type of work.
But if you want to skip the process, just take the car and drive right through, you will have a nice opening,that would be the same as doing what you want to do with out experience or knowledge :whistling
But if you want to skip the process, just take the car and drive right through, you will have a nice opening,that would be the same as doing what you want to do with out experience or knowledge :whistling
Anyway, not my expertise, but if I was doing it, say on my own place, - - I would probably needle with A.I. (as CanCritter said) through the course above where the lintel would go in two places to be safe, or even three if it's solid.
Just an opinon, though, - - as stated, best to get a professional involved.
Just an opinon, though, - - as stated, best to get a professional involved.
Why accuse him of being a homeowner when he clearly stated he wants to bid on the job??
First of all, if he was a professional contractor he would have an architectural drawing with all specifications and details, and he is asking how he should cut that wall and how should he support it while cutting.
Second of all he is asking what to use to support the wall while he is cutting the opening...How can some one tell him how to do it without seeing what he got there, other then the load of the block and grout which will rest on the required opening, which is approximate 9,540 LB, and that is if the block is grouted @16"... what about the load that rests on that wall.i,e roof, roof-top units, etc.
Third of all, being a professional, you can't give opinions without knowing the exact situation, because there is idiots out there who actually will go and cut openings in load bearing walls, and I would hate to see this guy end up with 15 courses of block on top of him... and here is just a small examples what happens when load bearing walls cut to make an opening without load calculation and proper beam sizing.
As you said yourself my friend, best to get a professional involved when doing structural modifications to load bearing walls.
First of all, if he was a professional contractor he would have an architectural drawing with all specifications and details, and he is asking how he should cut that wall and how should he support it while cutting.
Second of all he is asking what to use to support the wall while he is cutting the opening...How can some one tell him how to do it without seeing what he got there, other then the load of the block and grout which will rest on the required opening, which is approximate 9,540 LB, and that is if the block is grouted @16"... what about the load that rests on that wall.i,e roof, roof-top units, etc.
Third of all, being a professional, you can't give opinions without knowing the exact situation, because there is idiots out there who actually will go and cut openings in load bearing walls, and I would hate to see this guy end up with 15 courses of block on top of him... and here is just a small examples what happens when load bearing walls cut to make an opening without load calculation and proper beam sizing.
As you said yourself my friend, best to get a professional involved when doing structural modifications to load bearing walls.
Attachments
Just for fun speculation on how I'd do it if I were dumb enough to do it without covering my ass with a signed engineering plan.
It's not just the roof load you have to be worried about with that wall. You're going to have to account for holding up the bricks as well as it's demolished. I'd imagine that would take something along the lines of building a temporary header outside and inside the wall, and then running bolts through both headers and the wall to keep that brick from falling down. Then I'd bust out my concrete saw, cut my opening and then put in a steel I-beam or appropriate laminate beam to give support above my opening.
Minus the technical specs on what size bolts, etc, I'd imagine that's a possible plan that an engineer would recommend.
It's not just the roof load you have to be worried about with that wall. You're going to have to account for holding up the bricks as well as it's demolished. I'd imagine that would take something along the lines of building a temporary header outside and inside the wall, and then running bolts through both headers and the wall to keep that brick from falling down. Then I'd bust out my concrete saw, cut my opening and then put in a steel I-beam or appropriate laminate beam to give support above my opening.
Minus the technical specs on what size bolts, etc, I'd imagine that's a possible plan that an engineer would recommend.
Here ya' go, Brickie, - - here's some info for you, - - I'm sure glad these guys didn't come on this forum and ask any questions first . . . :laughing:
Question
Who performed first open heart surgery?
Answer
Daniel Hale Williams - Introduction: African American Doctor Daniel Hale Williams is credited with having performed open heart surgery on July 9, 1893 before such surgeries were established. In 1913, Daniel Hale Williams Williams was the only African American member of the American College of Surgeons.
Dr. Daniel Hale Williams in 1893? No!
Dr. Williams repaired a wound not in the heart muscle itself, but in the sac surrounding it, the pericardium. This operation was not the first of its type: Henry Dalton of St. Louis performed a nearly identical operation two years earlier, with the patient fully recovering. Decades before that, the Spaniard Francisco Romero carried out the first successful pericardial surgery of any type, incising the pericardium to drain fluid compressing the heart.
Surgery on the actual human heart muscle, and not just the pericardium, was first successfully accomplished by Ludwig Rehn of Germany when he repaired a wounded right ventricle in 1896. More than 50 years later came surgery on the open heart, pioneered by John Lewis, C. Walton Lillehei (often called the "father of open heart surgery") and John Gibbon (who invented the heart-lung machine).
http://wiki.answers.com/Q/Who_performed_first_open_heart_surgery
Question
Who performed first open heart surgery?
Answer
Daniel Hale Williams - Introduction: African American Doctor Daniel Hale Williams is credited with having performed open heart surgery on July 9, 1893 before such surgeries were established. In 1913, Daniel Hale Williams Williams was the only African American member of the American College of Surgeons.
Dr. Daniel Hale Williams in 1893? No!
Dr. Williams repaired a wound not in the heart muscle itself, but in the sac surrounding it, the pericardium. This operation was not the first of its type: Henry Dalton of St. Louis performed a nearly identical operation two years earlier, with the patient fully recovering. Decades before that, the Spaniard Francisco Romero carried out the first successful pericardial surgery of any type, incising the pericardium to drain fluid compressing the heart.
Surgery on the actual human heart muscle, and not just the pericardium, was first successfully accomplished by Ludwig Rehn of Germany when he repaired a wounded right ventricle in 1896. More than 50 years later came surgery on the open heart, pioneered by John Lewis, C. Walton Lillehei (often called the "father of open heart surgery") and John Gibbon (who invented the heart-lung machine).
http://wiki.answers.com/Q/Who_performed_first_open_heart_surgery
Hi everyone,
Interesting thread. Here's my two cents...
First, how much weight is on the wall from above? If only a roof, the roof could be supported with a temporary framed wall just inside the CMU. Assuming there is some horizontal rebar (an assumption that would have to be verified) above the opening, the hole could be cut and the "header" CMU that's left should be stable under its own weight.
I'd overcut the opening then install a steel beam and steel posts rather than trying to create a lintel of CMU.
If there's more than just a roof, the problem becomes stickier. Something I've done in the past is knock holes in the CMU, insert rebar, and grout full. Not easy or clean, but doable and can create a stout lintel in the right location so that the wall below can be cut out.
Lastly, if this wall is a shear wall, then cutting a big opening in it will diminish its shear capacity. Maybe there's enough wall left, but maybe not. If not, the steel beam on steel posts (moment frame) is good because it can take both gravity and lateral loads.
Someone suggested getting an architect involved. That's fine, but every architect I know would defer this to an engineer. So unless there's more to the project, save time and money and call the enigineer first.
Interesting thread. Here's my two cents...
First, how much weight is on the wall from above? If only a roof, the roof could be supported with a temporary framed wall just inside the CMU. Assuming there is some horizontal rebar (an assumption that would have to be verified) above the opening, the hole could be cut and the "header" CMU that's left should be stable under its own weight.
I'd overcut the opening then install a steel beam and steel posts rather than trying to create a lintel of CMU.
If there's more than just a roof, the problem becomes stickier. Something I've done in the past is knock holes in the CMU, insert rebar, and grout full. Not easy or clean, but doable and can create a stout lintel in the right location so that the wall below can be cut out.
Lastly, if this wall is a shear wall, then cutting a big opening in it will diminish its shear capacity. Maybe there's enough wall left, but maybe not. If not, the steel beam on steel posts (moment frame) is good because it can take both gravity and lateral loads.
Someone suggested getting an architect involved. That's fine, but every architect I know would defer this to an engineer. So unless there's more to the project, save time and money and call the enigineer first.
TimNJ,
I've never used precast lintels but imagine they're not too different than a steel beam. Just a structural member taken off the shelf and installed, right?
If you install a precast lintel or steel header in pieces, how do you join the pieces as you go along? If steel, I suppose the pieces could be welded. But I don't see how to connect pieces of a precast lintel. Am I missing something?
If "precast lintel" really means a cast in place lintel, that's a different animal completely. In that case, such a lintel could be created piece by piece, demoing the next section after the previous one has cured. Very doable. But the question becomes, how much can be demoed at a time? That answer needs to come from an engineer and is based on applied loads and strength of existing CMU.
No matter how you slice this, it's a sticky wicket.
I've never used precast lintels but imagine they're not too different than a steel beam. Just a structural member taken off the shelf and installed, right?
If you install a precast lintel or steel header in pieces, how do you join the pieces as you go along? If steel, I suppose the pieces could be welded. But I don't see how to connect pieces of a precast lintel. Am I missing something?
If "precast lintel" really means a cast in place lintel, that's a different animal completely. In that case, such a lintel could be created piece by piece, demoing the next section after the previous one has cured. Very doable. But the question becomes, how much can be demoed at a time? That answer needs to come from an engineer and is based on applied loads and strength of existing CMU.
No matter how you slice this, it's a sticky wicket.
Okay, now I get it. Cut out half the width, not length. So there is still support, though only half a wythe, until the first precast lintel is installed.
Why the wait between lintels?
Also, what if the cells upon which the lintels bear are not fully grouted?
Lastly, how are the lintels adhered to the existing CMU?
Why the wait between lintels?
Also, what if the cells upon which the lintels bear are not fully grouted?
Lastly, how are the lintels adhered to the existing CMU?
Around here nobody got lintels with #3 single re-bar, that is considered to be mild strength lintel. Every lintel sold here is #6 x 2 re-bar at the bottom, anything else special order.
Nice link Neo!
It still seems to me that it would be a lot less work, & probably safer to do it my way. Tearing out the stair step block would be a nightmare, not to mention replacing all those block, especialy at the new/old joint at the top. My way leaves them in place, with no chance of anything falling unexpectedly. For lintel bearing, you could just remove one block at each end, giving acces to fill core.
So what is the down side to my way?
Joe
It still seems to me that it would be a lot less work, & probably safer to do it my way. Tearing out the stair step block would be a nightmare, not to mention replacing all those block, especialy at the new/old joint at the top. My way leaves them in place, with no chance of anything falling unexpectedly. For lintel bearing, you could just remove one block at each end, giving acces to fill core.
So what is the down side to my way?
Joe
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