# Lintel size questions...



## Jamz51680

Okay...

We do alot of veneer masonry construction here in Central Texas and lately my methods have been questioned.

We currently use a 4"x6" x 1/2" Lintel with a span of 204" for masonry support over 16' garage door openings. We use 3/4" x 6" lags and we use 16 of them in to the GLULAM headers. We usually have around 60' of brick masonry above them being supported.....we are being questioned if our lintels are " thick " enough? 

Is my sizing correct or am I over doing it? We have been doing this for years with MINIMAL problems....and a couple problems arise and it's being questioned.

My other question which I'm not sure I know the answer to is when we brick over a window that is 6-8' wide we just use a loose 3"x4" x 1/4" supported on either side of the opening by the masonry and above that opening being supported could be another 8' of brick/stone. Is there a formula to figure out the size of lintel needed or something to help figure this out? They want them lagged to the wall, but above a window is usually a 2x4 and lagging in to that might mean trouble....

Thanks!


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## griz

Have an engineer draw it, calc it & wet stamp it.
You, me & everyone here can argue & by guess & by golly it, but then the liability is on us. If you build it like the engineer drew it it's on him. I'm not really interested in assuming any structural liability when it's too easy to avoid.


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## Tscarborough

They don't call them "loose lintels" for fun.

http://www.gobrick.com/TechnicalNotes/tabid/7658/Default.aspx

TechNote 31B will answer how to size them as well as why you do not need the lags.


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## Tscarborough

Griz, for normal masonry construction, there is no need for a structural engineer. The science is simple and well established.


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## griz

Tscarborough said:


> Griz, for normal masonry construction, there is no need for a structural engineer. The science is simple and well established.


Until you end up in court.
Being from the bankrupt state of Calif, I'll go with a wet stamp any day.
Besides, everything needs engineering out here.

I don't mean to come across like a prick. I very much respect your answers & opinions on this board. I just live in a screwed up state.


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## Jamz51680

Tscarbrough I see that you are vendor...by any chance do you do any on on the site consulting?

I am in the Austin area also.


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## Tscarborough

No worries, Griz, you are in a seismic zone, the OP and I are not, which makes it a whole different kettle of fish.


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## Tscarborough

Jamz, there is no need for onsite consulting, those tech notes should answer any questions that the owners or GC may have. 6x4x1/2 exceeds Austin code for a 16' opening anyway, although since you are probably having to buy it in 20' lengths you may as well get it cut to 18' at least. Be sure and back-cut the brick on the overlap.


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## dakzaag

A very simple rule that I found really helps in estimating the actual load of a lintel is the rule of an equalateral (sp?) triangle. 

While I don't know how to spell it for sure, I do know what it means. A triangle with all three sides the same length. If your opening width (16 feet in your case) forms the bottom of an equalateral triangle, the weight it supports is defined by the area within the triangle formed above the opening of equal length sides. 










The rest of the brick outside the triangle support themselves because of the natural bridging that occurs with commonly laid brick after it has set and become solid. 

I can say that I'm glad I don't have to help you set the lintels over your openings as they weigh about 275 lbs each. How do you spell hernia? :w00t:
The lags are only helpful to stabilize the opening until the mortar sets. Several well placed studs under the lintel would accomplish the same thing, but surely create more undeserved criticism that is not needed. You can safely tell your critics to shut up and help the next time your setting one. 

The only other force that must be accounted for is the side thrust that will occur on each side of the opening. If there is only a little wall to support the side thrust, then reinforcement may be necessary the absorb the thrust.









This opening is aproximately 16' and I know the lintel was no where near as heavy as you use. Again the brick that the lintel supports is the area above the opening in the shape of a triangle with equal length sides. The side forces are easily aborsbed by the brick on the right and the corner on the left. 

This is the rest of the addition just for bragging. :clap:


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## greg24k

Like Griz said, consult a licensed architect, and have him write you a letter confirming that is ok to use what you been using. Because if something is being questioned and you have a licensed expert who can put a seal on the piece of paper saying there is nothing wrong with it...then there will be no issues. 
You cannot bring to a table what anyone here will say when it comes to structural issues.

Obviously the people you doing the work for, have minimal issues and a few problems have arose and caught their attention, and now they question your way of doing work, the only way to prove them wrong is a letter from a licensed architect or engineer. 

I haven't checked the chart and don't hold me to it, but I think of the top of my head 4 x 6 x 1/2" can only span 14' with 1'4/6" bearing in masonry construction.


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## NJ Brickie

I am going to have to agree with Tscar on this. There are resources that provide this information. The GoBrick site he cited is a good one. One of the reasons these resources are available is to make masonry construction more competitive by not having to engineer every little thing individually. These calculations are industry standards and where done by engineers. Why pay for work that is already done?


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## Datadawg

NJ Brickie said:


> I am going to have to agree with Tscar on this. There are resources that provide this information. The GoBrick site he cited is a good one. One of the reasons these resources are available is to make masonry construction more competitive by not having to engineer every little thing individually. These calculations are industry standards and where done by engineers. Why pay for work that is already done?


Bump

+1
Every engineer I've ever dealt w/ has been brainwashed to fear litigation and liability and they invarably overspec to compensate for their fear. If the book or their calcs show a structural member can support 50 # PSF load, they will cut it by 20%... just so there can never be any failure -- ever. Basically, GC winds up paying higher cost of construction in material specs and labor for the litigation avoidance by engineer. If they spec a 6 inch slab vs 4 inch it's not a big deal, but it does add up. That $1PSF (just using a #) will cost another 7 cents in construction financing, another 3 to 4 cents in architectural fees (which are now often based on % of hard costs), another 6 cents in state sales tax if your state taxes services, and another 20 cents for GC OH and profit. So the customer eats a 20% bump to cost from overspec'd slab and another 5% overage for bleed through expenses. Having signed some of these checks over the years, it's always been a jaw grinding experience and pains me to this day.


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