Loose Lintel for Brick Veneer
Loose Lintel for Brick Veneer
(OP)
I am having a few issues with the loose lintels on a building project. The architect is showing 6" metal studs + 5/8" sheathing + 2" Rigid Insulation + 1 1/2" air space + brick veneer. This means that the total distance from outside face of sheathing to outside face of brick is 7 1/8". This leaves me with the need to update my lintel schedule on the job. I have sized a L7x4x3/8 lintel on a maximum opening width of 5'-0".
Limiting the deflection to L/600 and tip rotation to 1/16", I am finding that this L7x4 is right at it's limit. I'll have to have the architect move his joints off of the edges of the windows to ensure full arching action.
I am fortunate that I don't have any larger openings on this metal stud back-up.
My question is this: Have any of you encountered a similar condition? (This is the largest cavity I've seen. The architect tells me the new energy codes are driving this.) If so, are you moving away from loose lintels?
Thank you for your time and help.
Limiting the deflection to L/600 and tip rotation to 1/16", I am finding that this L7x4 is right at it's limit. I'll have to have the architect move his joints off of the edges of the windows to ensure full arching action.
I am fortunate that I don't have any larger openings on this metal stud back-up.
My question is this: Have any of you encountered a similar condition? (This is the largest cavity I've seen. The architect tells me the new energy codes are driving this.) If so, are you moving away from loose lintels?
Thank you for your time and help.






RE: Loose Lintel for Brick Veneer
BA
RE: Loose Lintel for Brick Veneer
I think the reason has something to do with flashing.
RE: Loose Lintel for Brick Veneer
BA
RE: Loose Lintel for Brick Veneer
RE: Loose Lintel for Brick Veneer
Batt insulation would work well here...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Loose Lintel for Brick Veneer
I am no expert on this part, but Current energy codes apparently require a certain amount of continuous insulation in addition to the batt insulation.
My primary question was whether or not you are seeing these types of details and finding them just as restrictive. I have seen these details on jobs for years now... though not quite as extreme as this. I have also compared our details to those of peers on several occasions... when the opportunities present themselves. Again, those situations were also a bit less extreme than the one I am describing.
RE: Loose Lintel for Brick Veneer
I would use a tube steel section as the window/door header within the studwall, perhaps with tube steel columns at the ends, then weld the ledger of the size needed to the tube steel header. The tube steel section is great for torsion...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Loose Lintel for Brick Veneer
RE: Loose Lintel for Brick Veneer
As we all know, architects make it pretty....we make it work.
RE: Loose Lintel for Brick Veneer
Rather: Architects provide the template for asserting efficient form and vernacular to impress the human response into a view of the emerging tectonic visualization and the effects of materiality on praxis.
Engineers make it work.
RE: Loose Lintel for Brick Veneer
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Loose Lintel for Brick Veneer
Also, how do you check tip rotation? Maybe I'm off here but with the angle so offset the end bearing will only be at the outside of the legs, the vertical will be hanging out in space - not much torsional restraint there.
RE: Loose Lintel for Brick Veneer
RE: Loose Lintel for Brick Veneer
FWIW, I think in most situations, the lintel just acts as formwork until the mortar cures and then the brick acts as a deep beam. I know we don't design as such, but I think this represents reality. Otherwise, we would see many more issues with brick veneer over large openings. One thing you can do is specify joint reinforcing in the first couple of courses of brick which tends to make it act like a reinforced masonry beam. I heard this from an engineer at the Brick Institute of America.
RE: Loose Lintel for Brick Veneer
I've modeled it several ways. I started with a beam model. Then I worked up a quick solid model in Femap/Nastran so that I could measure the tip deflection relative to the deflection at the vertical leg. I only constrained the part of the angle that would be embedded in masonry on each side of the opening.
RE: Loose Lintel for Brick Veneer
The loose lintel is the problem and it shouldn't pass throught the rigid insulation to the sheathing. In these environs, the angle against the sheathing could easily be at a temperature of -30C... As BA noted, it should be bearing on the ends of the adjacent veneer and his L4x4x1/4 would likely be OK.
Dik
RE: Loose Lintel for Brick Veneer
If you have gravity concerns. brace the lintel for a short period to allow the real load on the lintel be reduced by the structural properties of the masonry above., but I defy anyone to calculate the exact amount.
Going 2 stories between relieving angles is common, but going 3 or more creates problems creep/expansion with long term deflection of different materials (steel vs clay), but that is really an architects problem to control cracks and window leaks/alignment.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Loose Lintel for Brick Veneer
RE: Loose Lintel for Brick Veneer
I have dealt with this on one project to date, but it looks like that was just the beginning.
RE: Loose Lintel for Brick Veneer
We have multiple window openings spaced 1ft apart ( 4-5 ft wide windows opening size). My concern is:1 ft wide available brick wall support will act sufficiently for the bearing load?.
Any thoughts appreciated.
RE: Loose Lintel for Brick Veneer
Dik
RE: Loose Lintel for Brick Veneer
BA
RE: Loose Lintel for Brick Veneer
As the window openings are about 6 ft wide, I have jamb studs on every 6ft.
I see one of my option as attaching shelf angle to window header studs. Another option attaching only to jamb studs and spanning between jamb.As not much experience on light gage design system.
As Both of you Dik and BA mentioned about anchoring to back up system- do you guys means anchoring the lintel angle to jamb and header. Little more about anchoring types/details would help me alots.
thanks
RE: Loose Lintel for Brick Veneer
Trying to use the studs to support the lintel is a waste of time IMHO (I am a light gage designer) The light gage system is typically much more flexible than the brick in a vertical sense due to track to stud tolerances etc. Also, the brick may grow over time due to moisture absorbsion so the lintel may possibly want to pick up the framing at some point.
RE: Loose Lintel for Brick Veneer
RE: Loose Lintel for Brick Veneer
The brick pier is carrying a 12'x7' area of brick. At 40 psf, that would be 3360# which results in an average bearing of about 70 psi on the brick pier. That should be no problem for the pier provided it is laterally braced.
BA