Anchoring Into A Masonry Wall

[globe trekker]

Good morning all!

I have a set of plans for a Residential addition. The "drawer of the plans"

is indicating attachment of "new" treated wood studs to an existing exterior

brick veneer wall. Not sure why!

Is this proposed attachment [ of treated wood studs to an existing

exterior masonry brick wall ] allowed by code? We are using the 2006 IRC.

The "proposed" attached wall will be the exterior wall of the addition,

although all of it will be on the interior of the new addition. The "drawer

of the plans" has indicated to install the wall anchors in to the masonry

itself, and not in to the mortar joints.

Thanks for any input! Also, code sections please. I am under the

assumption that anchoring in to masonry is a "no-no"!

.

 

[Mac]

Here are a couple of code sections that might apply, depending on what your situation. From the NYS Res Code, based on the 2007 IRC:

R1003.8 Additional load. Chimneys shall not support loads other than their own weight unless they are designed and constructed to support the additional load. Construction of masonry chimneys as part of the masonry walls or reinforced concrete walls of the building shall be permitted.

R1003.18 Chimney clearances. Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51 mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25 mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1003.19. (followed by three exceptions)

Happy Friday!

 

[brudgers]

If the addition is four wall construction then it does not need to be attached to the existing with anything more substantial than a sealant joint.

Three wall construction requires selective demolition of the brick and proper attachment (or the use of an engineer to design a three wall structure.).

 

[globe trekker]

Thanks ya'll for your input!

The proposed addition will be a 4 wall enclosure, with only the one wall

being "proposed" to be attached to the existing exterior masonry wall.

There will be perimeter footings around all areas of the "proposed"

addition, so technically, this new "wall-being-attached-the-existing

masonry-wall" IS a load bearing wall, although minor in its

application [ 15 ft. in total length ].

The gist of my question to you all is: Can this "new" wall be attached

in to the masonry brick, ...is this an approved means of fastening /

attachment, or is this little more than some type of anti-swaying?

Thanks!

.

 

[David Henderson]

brick veneer same as concrete must be treated lumber in contact with such.

 

[brudgers]

If it is attached to the existing then it is not a four wall addition (i.e. four new structurally independent walls completely enclosing the new room - assuming it is a rectangle).

If the addition is not entirely structurally independent then the veneer cannot be used to transfer lateral loads into the existing structure and the attachment must be made to the structural wall.

 

[FredK]

So far I 'm with brudgers on this. If it could be a "stand alone" building how it's attached to another "stand alone" building doesn't matter. Tape, glue, or caulking could do the job.

Be way different if it was three sided.

 

[Mark K]

Brick veneer wants to be attached to a structural wall. I believe that this is clear in Chapter 14 of the IBC. To suggest that the code does not allow this suggests that the code is seriously flawed.

Having said that there may be difficulties in finding a way to anchor to the bricks, not the joints, without damaging the wall but I see that as the applicants problem and not the concern of the building department.

 

[Daddy-0-]

Brick veneer cannot have additional structural loads applied to it. Brudgers is on the right track. If you have a composite wall where the brick is structurally tied to the block then OK, but if it is veneer you cannot attach a deck, steps, addition or anything to it. Veneer is only designed to carry it's own weight and nothing more. I don't have the book with me but you can look in the foundation section to find some guidance. There is an air gap between the brick and the wall behind it. If you bolt through the brick and to the inside wall and then tighten the bolts you will collapse the air gap and cause a bad situation. The design as I am interpreting it is a no go. Like Brudgers said, remove some brick, install a lintel and properly attach to framing behind or have the addition completely independently supported. We turn down jobs weekly where the front porch rack bolts through the veneer. Just not a good idea.

 

[dhengr]

Doesn’t the IRC state that brick veneer should be attached to the primary structural wall and supported on the found. wall (a brick ledge) so as to support its own weight and so as to transmit wind, earthquake, lateral loads and the like into the primary structural system? And, that no other loads should be imposed on it, without special design considerations; it is just a heavy wall covering, not the primary structural system. Thus, deck ledgers, other concentrated vert. loads or lateral loads, etc. should not be imposed upon it.

You either have to make your addition free standing, or check the existing structure for all new superimposed loads. If it is free standing then you still have to worry about relative movement vert. and horiz. at the connection, and at the roof system. If the addition is attached, I would do something to bond the two founds., attach the new structure at the found. sill pl. and rim joist and also at the double top pls. and roof. And, I would cut an opening through the brick veneer to make these attachments directly to the existing framing. Of course, this opening should be properly finished, flashed and caulked. Then the entire connection must be detailed to be weather tight.

Brick veneer is actually far stiffer in plane than the wood framing; but is not so strong w.r.t. loads perpendicular to its plane, or concentrated loads, where tensile stresses and high shearing and bond stresses come into play. In residential work brick veneer is often suspect as to the quality of materials used, workmanship, and proper tie-backs to the structure. If brick veneer is properly designed, speced, and installed in the first place to accommodate special loads it should do fine in taking gravity loads and lateral loads in its plane. But, for lateral loading perpendicular to the plane of the brick wall, you still have to tie back into the existing floor diaphragms and the like. And, you can’t count on any of this on an addition, where you know nothing about the brick or mortar strength, what percentage of ties were never installed or have corroded away, and no design provision was made in the veneer for your new loads. Thus, the prohibition against attaching directly the brick veneer.

 

[globe trekker]

Thank you all for your input! In this particular case, I agree that the brick

masonry is not an approved material to be fastening / anchoring to,

regardless of any minimal lateral loads.

The wood framed walls will be attached together at the top plates and

at the bottom sill plate. The sill plate to the "new" foundation area, that

will be attached by doweling in to the existing foundation, so it is all

fastened / tied together sufficiently.

My main question has been the "proposed" use of masonry bolts or

screws in to the existing masonry wall. After discussing it with ya'll on

here, I am satisfied that there is enough attachment in other areas to

not be concerned with any masonry fasteners used. The "drawer of the

plans" is not a DP or RDP! I am questioning the "proposed" indicated

design of trying to use fasteners in to the masonry and not all the way

through them in to the wood studs. Ya'll have helped me greatly to think

through this issue! Again, "much thanks!"

The Rest of the Story: Because of the lack of understanding of

construction dynamics, ..various loads and forces involved on the built

environment, ..lack of adequate information submitted on the plans, ..by

actual use and application of the adopted codes & ordinances, and overall

lack of adequate planning by the homeowners, ...one plumbing

contractor, ...the "drawer of the plans" and the homeowners representative,

this particular project has become quite politically sensitive. Our dept.

was accused of "holding up the project", ..of being too hard on the

homeowners [ by enforcement of the adopted codes ], ..by incorrect

interpretation of the codes and on and on. I know that a lot of you have

to deal with this type of environment & attitude too [ I feel for you

" Alias! " ]. Some days it just gets to be overwhelming trying to be a

good public servant.

Now, instead of one inspector going out to perform the various

inspections on this project, our dept. will have to send two, so as

to ensure that no miscommunications or allegations are submitted

[ the CYA Factor ].

:banghd :banghd :banghd :banghd :banghd :banghd

.

 

[steveray]

R703.7.3 (2003) maybe.....thought there was something clearer,,,,but I know you are not supposed to attach to veneer per IRC