# cutting an opening 9'by 9' in a block wall



## WRer

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:


----------



## Railman

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


----------



## griz

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.


----------



## CanCritter

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


----------



## Warren

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.


----------



## Railman

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


----------



## griz

Railman said:


> 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


The problem will be being responsible for all the liability should something go wrong. Maybe where you guys are at it's no big deal. But out here with all the attorneys we have and inspectors running around with nothing to do but look for non-permitted work I would not touch this without wet stamped drawings and a permit.


----------



## NJ Brickie

griz said:


> The problem will be being responsible for all the liability should something go wrong. Maybe where you guys are at it's no big deal. But out here with all the attorneys we have and inspectors running around with nothing to do but look for non-permitted work I would not touch this without wet stamped drawings and a permit.


 I think you are right on this one. Too much can go wrong very easily. I started to write a response on this one and decided not to post it because it does not seem like the OP has experience doing something like this and the effects could be very dangerous. Based on the posts so far I would like to add that shoring was only briefly touched on by Warren and is the most important part of this project. I have cut masonry openings into many load bearing walls and based on the posts there is alot of critical information left out. If you take the job good luck and be careful.


----------



## Brickie

If you've never done anything like this before, I would recommend that you sub it out. I fix a lot of FU created by inexperienced people with the "it's no big deal, any mason can do it" mentality.


----------



## greg24k

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


----------



## Tom R

Why accuse him of being a homeowner when he clearly stated he wants to bid on the job??


----------



## Tom R

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.


----------



## greg24k

*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.


----------



## katoman

And what a PITA to fix that stuff.

We should tell him to just go for it and next year there'll be a nice job for a real GC to fix up. :whistling


----------



## Tom R

Every professional was once a newbie, - - even those of you who will never admit it . . .


----------



## katoman

Tom R said:


> Every professional was once a newbie, - - even those of you who will never admit it . . .


I'm just being a smart ***. I'm sure the OP will consult as needed and be fine.

And just FYI Tom, my mother had a heck of a time in delivery with me - couldn't get the Estwing out. :laughing:


----------



## Tom R

katoman said:


> I'm just being a smart ***. I'm sure the OP will consult as needed and be fine.
> 
> And just FYI Tom, my mother had a heck of a time in delivery with me - couldn't get the Estwing out. :laughing:



My comment wasn't directed at anyone in particular, - - it just seems easier to me to not answer a question if I choose not to, then to jump on the guy for asking the question.

I see it getting done here all the time, - - maybe someone should start a 'non-information' forum and see how busy it gets . . . :shifty:


----------



## neolitic

greg24k said:


> *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.


Maybe where you are, not necessarily
every where.



greg24k said:


> 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.


Exclusive of the roof load,
I'd guess that the weight of
masonry carried over that opening
would be more like 5700lb (fully grouted),
or 2800lb if not grouted.
The bearing steps up at a 45º angle,
so you are distributing the remainder
of the load above, beyond the 9X9 opening.


----------



## Tom R

In case anyone missed it in the OP . . . 



WRer said:


> I *have to bid on* cutting a 9feet by 9feet opening for garage door.


----------



## neolitic

If it's a stack bond, I'd be 
a tad more conservative though.


----------



## Brickie

Tom R said:


> In case anyone missed it in the OP I *have to bid on* cutting a 9feet by 9feet opening for garage door . . .


So he has to bid on something that he has no clue on how to do?????


----------



## Tom R

Brickie said:


> So he has to bid on something that he has no clue on how to do?????



Should the trade die when you do??


----------



## Brickie

Tom R said:


> Should the trade die when you do??


 
That's an idiotic thing to say Tom. :jester:

Using your "logic" you would bid on doing open heart surgery even though you never went to school for it, never interned, & basically have no freakin clue except you "have to" in you mind.:laughing:


----------



## BuildersII

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.


----------



## Tom R

Brickie said:


> That's an idiotic thing to say Tom. :jester:
> 
> Using your "logic" you would bid on doing open heart surgery even though you never went to school for it, never interned, & basically have no freakin clue except you "have to" in you mind.:laughing:



Sorry, Brickie, - - the closest your trade will ever come to rocket science or heart surgery is during your dinner table conversations.

Don't worry, - - I won't tell your wife and kids . . . 


The guy is not going to pay an architect or engineer to 'bid on' a frikkin' job.

And I doubt if he'll make a decision to sit some job out rather than put dinner on his table because some guy named Brickie on the internet wants to protect some 'imaginary secret' that he never owned to begin with.


For all we know, - - that may just be a single part of bigger job that he's bidding on, - - and he was planning on calling 'you' to come in and actually do it. 

But alas, - - now he'll probably go to some other self-declared genius.


----------



## Tom R

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


----------



## neolitic

BuildersII said:


> 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.


We "needle" and set picks to cut
openings in masonry walls all of the time.
It really isn't rocket surgery, if you
understand the principle of the arch
and transference of loads.


----------



## TimNJ

Tom R said:


> The guy is not going to pay an architect or engineer to 'bid on' a frikkin' job.


That's what I was going to post and you beat me to it.
The owner is probably kicking tires at this point and trying to get a feel for what kind of $$$$ he is going to have to put out. 
Give him the ballpark and tell him that price doesn't include the engineers fee or permit fee since you are altering the structural integrity of the building.


----------



## greg24k

neolitic said:


> Maybe where you are, not necessarily
> every where.
> 
> 
> 
> Exclusive of the roof load,
> I'd guess that the weight of
> masonry carried over that opening
> would be more like 5700lb (fully grouted),
> or 2800lb if not grouted.
> The bearing steps up at a 45º angle,
> so you are distributing the remainder
> of the load above, beyond the 9X9 opening.


I know how the load transfer works, what he is asking 
*" 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"*

and I think you off with your grouted and not grouted calculations.
12" concrete block wall is 80LB PSF that 7,200LB PSF just above that opening.


----------



## Brickie

Tom R said:


> Why accuse him of being a homeowner when he clearly stated he wants to bid on the job??


 
Well Tom, Since you happen to be a wood butcher & not a Brickie, one can see why you might be confused. :laughing:


----------



## neolitic

greg24k said:


> I know how the load transfer works, what he is asking
> *" 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"*
> 
> and I think you off with your grouted and not grouted calculations.
> 12" concrete block wall is 80LB PSF that 7,200LB PSF just above that opening.


My supplier says 70lbsqft.
Maybe it depends on how many webs....
Even so, it is still only
40.5sqftX80lb=3240lb,
give or take, that would be bearing 
on the lintel (exclusive of roof load.)
It is a triangle 9' at the base and
4½' tall, or 40.5sqft.


----------



## BuildersII

neolitic said:


> We "needle" and set picks to cut
> openings in masonry walls all of the time.
> It really isn't rocket surgery, if you
> understand the principle of the arch
> and transference of loads.


Dumb question time: what's needling? I'm assuming it's running a bunch of tapcons through a board and the wall.


----------



## Brickie

Tom R said:


> The guy is not going to pay an architect or engineer to 'bid on' a frikkin' job.
> 
> And I doubt if he'll make a decision to sit some job out rather than put dinner on his table because some guy named Brickie on the internet wants to protect some 'imaginary secret' that he never owned to begin with.
> 
> 
> For all we know, - - that may just be a single part of bigger job that he's bidding on, - - and he was planning on calling 'you' to come in and actually do it.
> 
> But alas, - - now he'll probably go to some other self-declared genius.


 
Just like your posts in P & R, you expose yourself as a clueless self appointed expert:laughing::laughing::laughing:


I know Tom that this may be difficult for a wood butcher like you to follow


OP claims to be a "Concrete & Masonry Contractor"

He then asks a question that any 1st year apprentice would know the answer to. 

In other words wood butcher Tom: *Basic Masonry 101:w00t::w00t::laughing::laughing:*


----------



## rustyjames

BuildersII said:


> Dumb question time: what's needling? I'm assuming it's running a bunch of tapcons through a board and the wall.


It's just another reference to underpinning.


http://www.coateshire.com.au/products/prod.aspx?G=32&P=546&S=45


----------



## greg24k

neolitic said:


> My supplier says 70lbsqft.
> Maybe it depends on how many webs....
> Even so, it is still only
> 40.5sqftX80lb=3240lb,
> give or take, that would be bearing
> on the lintel (exclusive of roof load.)
> It is a triangle 9' at the base and
> 4½' tall, or 40.5sqft.


In NJ the basic is 80LB PSF , most use 100LB PSF including mortar, dura-wall every other course etc. Your calculations 100%, your wall height if off thats the only difference we have...He said the wall was 24 courses, thats a 16 foot heigh wall...I took 9 courses out (should be 10) that was left with 15 courses that 10 feet of wall remaining above x 9' wide = 90 (sqft) X 80 lb= 7200lb if cut 10 courses out we would end up with 84 sqft x 80LB with a load of 6720 lb. 
Anyhow, thats not important, the important thing is he shouldn't be here asking this, he should contact an architect and have a plan, then hire someone who knows what they doing, because he is obviously has no clue whats going on.


----------



## Brickie

greg24k said:


> Anyhow, thats not important, the important thing is he shouldn't be here asking this, he should contact an architect and have a plan, then hire someone who knows what they doing, because he is obviously has no clue whats going on.


I agree:thumbsup:


----------



## neolitic

greg24k said:


> In NJ the basic is 80LB PSF , most use 100LB PSF including mortar, dura-wall every other course etc. Your calculations 100%, your wall height if off thats the only difference we have...He said the wall was 24 courses, thats a 16 foot heigh wall...I took 9 courses out (should be 10) that was left with 15 courses that 10 feet of wall remaining above x 9' wide = 90 (sqft) X 80 lb= 7200lb if cut 10 courses out we would end up with 84 sqft x 80LB with a load of 6720 lb.
> Anyhow, thats not important, the important thing is he shouldn't be here asking this, he should contact an architect and have a plan, then hire someone who knows what they doing, because he is obviously has no clue whats going on.


Greg, think "arch."
The lintel will not actually bear
the entire height of the wall
above the opening.


----------



## neolitic

BuildersII said:


> Dumb question time: what's needling? I'm assuming it's running a bunch of tapcons through a board and the wall.


Knocking holes above a 
proposed opening, and setting
temporary picks to bear the
load until the opening is finished
and lintel is set and masonry
filled in.


----------



## Tom R

BuildersII said:


> Dumb question time: what's needling? I'm assuming it's running a bunch of tapcons through a board and the wall.



Not a dumb question at all, - - this forum is supposed to be to share information, - - this pic here should help you (and others) envision 'needling' . . .

These needles (steel is often used) would be put in the course above the one you're going to lintel, - - then after you've demo'd your opening and installed your lintels, - - you would just replace the individual (in his case) blocks you had your needles through . . .


----------



## neolitic

Tom R said:


> Not a dumb question at all, - - this forum is supposed to be to share information, - - this pic here should help you (and others) envision 'needling' . . .
> 
> These needles (steel is often used) would be put in the course above the one you're going to lintel, - - then after you've demo'd your opening and installed your lintels, - - you would just replace the individual (in his case) blocks you had your needles through . . .


Well, you gotta show me up
and bring *pictures* and stuff!

I bet you wuz the star of Show and Tell Day! :laughing:


----------

