Brick Veneer on 4-story wood bldg
Brick Veneer on 4-story wood bldg
(OP)
What are some opinions on supporting brick veneer with a wood backing? This building is around 45' tall with brick veneer. Code seems to allow brick to span from the foundation upwards of 30' before needing a shelf angle. Has anyone fastened a steel shelf angle to the exterior wall studs with lag bolts to support the masonry?






RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
I did a 4 story wood hotel and that same issue came up. I checked the stresses in the masonry and they were fine. The brick was installed all the way up only being braced back to the studs in the usaul manner all the gable ends and hasn't fallen down yet. I think its been 7 or 8 years.
All that to say I am not sure if it is code compliant, but it will work.
RE: Brick Veneer on 4-story wood bldg
Does that mean that if you have a wood building with brick veneer, you are always going to have all the brick supported at the foundation level?
What if, instead of having a shelf angle connected to woods studs, you had it tied into blocking or a double-top plate?
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
The IBC is explicit (in the anchored veneer section) that the brick should only go 30 feet in height where supplemental shelf angles are required. I'm not sure that I would want brick veneer to be supported by wood structures in any case. Can you convince the architect to convert to EIFS in the top story?
RE: Brick Veneer on 4-story wood bldg
1) IBC 1405.5 says anchored veneer shall comply with ACI 530, sections 6.1 and 6.2
2) ACI 530, section 6.1.2 says anchored veneer shall be designed rationally per 6.2.1, or by the prescriptive requirements of 6.2.2.
3) 6.2.2 (specifically 6.2.2.3.1.2) has a height limitation; 6.2.1 does not appear to limit the height.
4) I have done a 4 story wood structure, with the brick veneer all supported on the foundation, and had no problems whatsoever.
RE: Brick Veneer on 4-story wood bldg
If I were going to hang brick on a wood frame structure, I would have shelf angles every two floors at the most. - With appropriate details per code.
RE: Brick Veneer on 4-story wood bldg
Clay brick has an irreversible long term expansion. If you have concrete brick, the long term effects are for shrinkage, which is more compatible with structural materials under compression. Concrete brick is not a large percentage of the brick used, but it is increasing.
Wood is subject to creep/shrinkage so the long term dimensional differential can be appreciable over a long period. The biggest problems occurs at openinings on the upper (depends on distance above the veneer support). A similar situation exists for concrete structures, but not to the same degree.
Dick
RE: Brick Veneer on 4-story wood bldg
"Section 6.2.2.3 of ACI 530 regulates the vertical support of anchored masonry veneer. Section 6.2.2.3.1.2 and Table 6.2.2.3.1 limit the height of the veneer above noncombustible foundation. An exception is given for veneer with a backing of cold-formed steel backing, Section 6.2.2.3.1.3. There are no restrictions on the height of veneer backed by concrete or masonry. This is a fire protection requirement. The designer should also consider the effects of differential movement on the anchors and connection of the veneer to other building components. See Commentary Section 6.2.2.3.
As this restriction is fire safety related, additional calculations would probably not be a sufficient proof for an alternative approach
Sincerely,
Technical Staff"
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
I think the only solution to comply with both the 30 foot rule and the above is to use strucural steel to support the brick between the wood studs all the way down to the foundation. Talk about overkill.
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
“Wood members supporting concrete, masonry, or similar materials shall be checked for the effects of long-term loading using the provisions of the NDS. The total deflection, including the effects of long-term loading, shall be limited in accordance with 1604.3.1 for these supported materials. “
Design and detail accordingly
RE: Brick Veneer on 4-story wood bldg
I'd secure the shelf angles using through bolts at each second floor. You should have a minimum 1/4" gap between the shelf angle and the course below which should be foam rodded and caulked.
Dik
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
Dik
RE: Brick Veneer on 4-story wood bldg
"It is common for wood structural elements to support
masonry and concrete construction. When properly designed,
taking into consideration long-term deflection,
wood can adequately support these products. The limitations
on wood supporting masonry and concrete are
recommended by that industry. Masonry and concrete
are brittle materials, which do not tolerate movement.
Wood is hygroscopic, meaning it changes dimensions
as a result of absorbing or releasing (drying) water.
When improperly detailed, dimensional change in wood
can result in damage to masonry and concrete.
The exceptions provide some relief. Flooring and roof
coverings meeting specific thickness criteria may be
supported by wood. The wood must be designed to
carry the weight of the material. A strict interpretation
would prohibit wood piles from supporting buildings
containing masonry or concrete components; an exception
permits this. Likewise, brick veneers are permitted
to rest on foundation walls constructed using the permanent
wood foundation system. Lastly, glass block can
rest on wood floors, provided consideration is given to
deflection and shrinkage."
Don Phillips
http://worthingtonengineering.com
RE: Brick Veneer on 4-story wood bldg
just a minor clarification: hygroscopic doesn't necessarily mean there are dimensional changes; with wood, there are... just means that it can absorb/absorb water from surrounding air/environment...
Dik
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg
I believe you violated the code if you didn't do the rational analysis and if you exceeded thirty feet or whatever the limit stated in the code is. I had to look at a building where several years (8-10 years I think) after construction bricks started popping off the building and hitting the sidewalk below. Luckily no one was injured. I discovered the relief angles had been installed directly on top of the brick below. Now this was a 10 story concrete frame building. The brick was being crushed as the building shrank/brick expanded. Also the masons decided not to put in any brick ties about 3/4 of the way up, big hole formed there.
J
RE: Brick Veneer on 4-story wood bldg
How often do you go back to look at problems that have a long term potential?
The brick expansion is not a typical moisture wet/dry expansion/contraction contraction. There is an irreversible long term expansion that is masked by moisture early in the life of a structure.
Dick
RE: Brick Veneer on 4-story wood bldg
RE: Brick Veneer on 4-story wood bldg