Brick deflection

Specific Inspection Topics Exterior Inspections
21

Here is the problem?

When I inspect a home it is a visual inspection. I do not us instruments to test the deflection in walls, no do I use scopes inside walls, or so I put arbitrary amounts of pressure on walls ceiling or other components of the home. This is not part of the inspection.

However, the buyers “Friend” an “expert” in home repair does. So he goes around pressing on walls etc. and find if he shoves on one part of one wall he can cause it to move up by the freeze board.

Ok, so to answer the buyer, who has not bought the house, he wants to know why it does this, what is wrong, what has to be done, and why didn’t you see this.

So to actually answer this, I need to know what is the allowable amount of movement, and since it was built 35 years ago, what was the building requirement then.

My guess is I can’t find one.

So if there isn’t a requirement, then it is functioning as designed.

Yes, it may not need this movement, and in general opinions it should not move. But, if it can be moved, then what is the stress factor that should be used to calculate this. Opinions can vary. That is why there are building codes and design requirements. My opinion is not official, neither is the opinion of his friend. Now my wife can’t move the wall, I can move it if I press on it over my head. I don’t know the size of the person that moved it.

So, if it moves, what is the appropriate pressure at what location to determine the affect.

Do any of you test the walls?

22

Wow pete …wish you had some pictures so we could see more to determine what is going on.Is trhis regular brick veneer like in Marcel’s PDF and how big is the wall?Does it have flashing?If you look at the PDF you will see that the wall does not support , but is being supported buy the foundation and the ties.

23

If the brick veneer moves at all, there’s got to be a crack somewhere. If the crack is at the brick shelf of the foundation, then hopefully there is flashing that will protect somewhat against water entry,unless water can get in under the flashing. If the movement is limited to only the upper part of the wall, then there’s a crack somewhere in the middle, which may be only a hairline crack, and may or may not offer a problem.

It also depends on exactly how much movement there is…is is 1/16 inch or 1/2 inch? In any case though, the brick ties, which may not be exactly like the ones shown in a PDF that was posted here, but may only be simple sheet metal strap ties, will allow for a limited amount of the kind of movement you created when you pushed on the wall. There is nothing in construction which is infinitely stiff, or doesn’t deflect under load.

24

Here is an example of a more flexable brick tie.

25

Hi. Peter;

As Bob mentioned, picture would be of tremendous help, but anyways.

If what I follow in what you are saying, the brick wall moves when pushed on it, that is definitely wrong.

Any brick wall veneer installed on residential facades with a wood stud anchor ties will be spaced at a maximum of 32" horizontally and 16" vertically.

Corrugated ties should be installed at the next to top course of the brick veneer. If ties were installed on that course at no more than 32" apart, you would not be able to move the veneer.
Anchoring the top of the brick veneer second course down was important so when soffit moldings or frieze boards or whatever you may call it, the bricks would not move at free will and crack the joints.

That was the procedure 35 years ago and still exist today.
Commercial is a little more stringent.

The closed in soffits back then were usually enclosed using 3/8" AC plywood with a continuous 2" vent strip or a rectangular vent in the joist bays.

Since the boxed in soffits were framed in usually before the brick, the continuous ledger for the out lookers was attached to the house.
So, when the brick was installed, you did not have continuous nailing member parallel with the brick facade. If the framing was at two feet on center, this would create a lot of up and down motion between the framing or waviness in the soffit material and or molding that was against the brick.

If the brick wall moves, I would certainly write it up as needs to be repaired or further evaluated by a Masonry Contractor and Building Contractor efforts.

Hope this helps if I understand the question right.
Remember, I am in Maine and you are in Texas, the framing and building methods are quite different.

Marcel :slight_smile:

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26

That is a very well thought outexplaination.

I guess I better start pushing on walls, and maybe gain a little weight… Now if I could only gain a little more height.

I guess you live and learn. I learned a valuable lesson and fortunatly before it became an expensive lesson.

I did find this artical today that may be good for others, as I found it good for me.

<SPAN style=“FONT-SIZE: 10pt; LAYOUT-GRID-MODE: line; FONT-FAMILY: Arial”>TIE SELECTION
**Strength and Deformation **
**The strength and deformation characteristics of tie systems are not generally analyzed nor investigated during the project design or specification phase. Building codes and standards have typically required minimum tie size (diameter or gage) and maximum tie spacing limits to control tie loading and deformation. Present tie size and spacing requirements have been derived from some testing and from the past performance of traditional tie systems (rectangular ties, "Z’’ ties and standard joint reinforcement). The growing use of adjustable tie systems has caused some concerns in regard to tie strength and deformation. Most adjustable ties permit vertical adjustment up to approximately one-half the height of a standard brick unit, some permit greater adjustments. Depending on the tie configuration, the deflections of adjustable ties can become quite large as vertical adjustment eccentricities are increased. This deflection is further increased if mechanical play is present in the tie system. ******
**Analytical and experimental investigations of cavity wall and veneer wall systems have shown that tie loads and deformations are a function of: 1) the relative stiffness between facing and backing materials, 2) tie spacing, 3) tie stiffness, 4) support conditions of the facing and backing systems, 5) location of edges and openings, 6) cavity width and 7) applied loads. ******
Estimating tie loads based on tributary area can lead to large errors, depending on the geometry and properties of the wall system. Fig. 12 shows tie loads and deflections calculated from a simplified model of a cavity wall system. As shown, adjustable tie deflections become large as the adjustment eccentricity becomes large. These values were calculated assuming that no mechanical play existed in the tie system. Mechanical play must be added to these values to determine the total deflection of the exterior wythe. Typical adjustable ties have values of mechanical play ranging from approximately 0 to 0.3 in. (0 to 8 mm). Some adjustable ties may have an extreme amount of mechanical play when not properly installed (see Fig. 13). The MSJC Code limits mechanical play to a maximum of 1/16 inch (1.6 mm). If satisfactory performance is to be expected, total tie and backing deflections must be maintained within the working range of the masonry facade under full design loads.

27

Peter,

Just because it’s been there for X-number of years does not mean it will continue to be functional.

I had one in Lewisville that you could rock the wall to where the soldier course would touch the substrate.
BTW, yes I do hand pressure test all brick veneer walls.
They disregarded my concerns and bought as is.
The very first storm that came through had wind shear events it was a John Mellencamp Crumblin’ Down moment.
The rest of the story is they had to contact a mason; which is what I suggested to begin with.

28

Hi Barry,

Just to help figure out a good system, how do you check a 2 story?

I’m not sure I can put the ladder up, and get enough pressure.

On a tall one story do you use a ladder and move it x feet and do the test, or just randomly select a spot.

For example, on the house I’m refering to, it’s a 1 story about 3100 sq feet. One spot moves?

Any advise is appreciated.

Pete

29

If the bricks move, then there has to be cracks somewhere. Maybe they are nearly microscopic, but there isn’t much flex in a well-built brick veneer. A joint somewhere must be allowing movement. Does the brick move at a corner, or in the middle of the wall? Is there brick veneer on only the one wall, or on the entire house?

30

Cracking can also result if the mortar is too hard or inconsistant, or it shrinks leaving hairline cracks.

31

You know one I have noticed is that these masonry guys miss the studs a heck of a lot.The ties may be loose.Hmmm