Agricultural Science Building – Inspection & Assessment

As students in AE 537, Building Performance Failures and Forensic Techniques, you were asked to visit the site of the Ag. Science Building and perform a preliminary condition assessment with an emphasis on the site walls and the building facade system.  Working in small groups, you documented the condition of various building components and reported them in a short summary report.  Some of the original working drawings were provided for your review to help in your understanding of the systems.

The second phase of this assignment is to participate in a discussion forum on this page (as individuals) to describe and report what your observations were and identify any trends or concerns discovered.  As individuals, this forum is open for your comments, questions and observations.  You are encouraged to discuss potential causes of any deterioration or problems you report as well as providing links and citing appropriate sources.  While the team reports are not being  provided, some photos will be posted and numbered or named for reference purposes if it helps your discussion to reference them.

 

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Photo 1: What observations did you make one way or the other relative to this section of the facade?

Photo 2:  Any observations or conclusions relative to this, or other, masonry movement joints?

Photo 2: Any observations or conclusions relative to this, or other, masonry movement joints?

Photo 1:  Did anyone document this condition?

Photo 3: Did anyone document this condition?

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35 Responses to “Agricultural Science Building – Inspection & Assessment”

  1. Garrett S
    December 2, 2014 at 9:37 am #

    In regards to photo 1, there has been discussion of water penetration, brick discoloration, and efflorescence. There could be many causes of this but I think a contributing factor may be the discontinuous vertical expansion joint. Upon closer inspection of the the photo, the expansion joint is discontinuous from the window sill to window head. Since there is considerable horizontal expansion at openings, there would need to be some sort of expansion joint here in order to accommodate horizontal movement. A joint may have been installed along the jambs of the window which would provide that expansion. However, the discontinuity in the expansion joint could present some differential movement in the brick, creating separations in the sealant and masonry, allowing some water penetration to occur.

    I believe the reason the joint is discontinuous is because there isn’t much surface area of brick in between the windows. An expansion joint through the middle of that narrow section could cause some structural instability. In order to avoid that situation, the entire expansion joint could have been shifted to align with the jamb of one of the windows. That way it could have been continuous across the entire vertical face.

  2. Jim P
    December 2, 2014 at 8:36 am #

    Did any other groups investigate inside the building for failures? I know the assignment was primarily facade investigation, but inside the building, we found a lot of leaks leading to discoloration of drop ceiling tiles (some even being so bad as to be visibly moist and moldy) and, possibly more concerning, was what appeared to be differential settlement of the auditorium relative to the rest of the building. According to the drawings, half of the auditorium is located over the basement, and the other half (which slopes away from the building) has no basement; it just lies on a wall footing. This coupled with the irregular shape of the building, I thought may contribute to what appeared to be differential settlement. Thoughts?

  3. Julia H
    December 1, 2014 at 5:55 pm #

    One of the most concerning failures our group noticed was a brick spall located directly above a commonly used building exit. A few portions of brick had already spalled off, and a few more bricks appeared to be quite loose. This was deeply concerning given that the brick could spall off and fall in front of the doorway, or possibly even hit somebody.

    Though there were a few spall locations around the building that were very serious, as in Figure 3, this one seemed the most concerning to me due to the accessibility of the door.

  4. Jim P
    November 23, 2014 at 4:11 pm #

    An interesting failure my group discovered (though we didn’t include it in our report) were sealant failures around windows, especially on the ground floor of the north-facing side. It appeared as though new sealant was gooped on overtop of failed sealant without removing the old sealant. See link for photo:
    https://lh3.googleusercontent.com/qBlURj5VSkURQ4JZ3odNpP7NA65NDGvS5OEwWK98p62pW6Jfw_70pq7d7DO-CDRYLsoc_w=w1342-h504

    • mkev
      November 30, 2014 at 5:43 pm #

      Sealant over sealant without removal is never a good idea. If it was somewhat widespread, then we can count out an isolated emergency repair.

      I couldn’t link to the photo. Did you set the correct permissions? If you can repost, that would be great. If you can’t make it work for all, send the original photo to mkp and I will add it as Figure 4.

      • Adam J.
        December 1, 2014 at 11:54 pm #

        Our group also noticed the sealant over sealant condition on the basement windows of plan north. It appeared to be an adhesion failure of the new sealant from the window. In areas where the new sealant had sufficiently separated from the old, it was apparent that the old sealant was in a similar condition to other sealant joints around the building. I am not sure of the specific reason why the sealant was just applied over the old sealant other than a quick fix. The same color sealant was used in all window, in strong contrast to the old sealant. Therefore the fix was required everywhere, however was installed properly.

        P.S. mkp, I sent you a copy of our groups close-up photo of the new sealant separating from the old sealant at the top of the window.

  5. Yewande A
    November 20, 2014 at 7:56 pm #

    My observation from Photo 1 is that the horizontal building expansion joint is compressed and deteriorated, it seems that the backer rod might be absent or it may have been excessively compressed causing the sealant to lose it’s shape and the joint becoming smaller. The brick is also in poor condition, as many have noted there is spalling, discoloration and efflorescence. Most of these are as a result of moisture penetration on the wall due to improper detailing of weepholes and flashing to appropriately divert water from the wall.

    • mkev
      November 30, 2014 at 5:40 pm #

      Yes, much of the sealant is in poor condition. I don’t know when or if it has ever been replaced. So, adding to comments on size and shape, we could have an improper sealant for the joint size in terms of the percentage of movement that the joint sealant can have. Improperly specified or improperly supplied sealant adds to the possibilities.

  6. Christopher B.
    November 20, 2014 at 10:30 am #

    Our group noticed that the brick facade in the atrium appears to transition from exterior to interior without a thermal break. The adjacent gypsum or storefront wall systems abut directly to the brick.

    • mkev
      November 30, 2014 at 5:38 pm #

      Nice observation. I didn’t spend anytime on the interior. If that is the case, however, it would be similar to that problematic detail / condition that Mr. Rose from SGH showed you in his lecture. Could it be that such a condition is more common than we thought even though it defies common sense?

      • Christopher B.
        December 1, 2014 at 7:26 pm #

        On the topic of thermal bridging, I went back and looked at the Ag. Sci. wall sections and it does not appear that the steel shelf angles are insulated where they are attached to the concrete structure. A report published by RDH Building Engineering LTD. of Canada (link below) identifies Ag. Sci. type details as “baseline” shelf angle support options that can result in significant reduction in R value for the wall assembly. The report offers some improved details that can better insulate the angles and maintain the thermal integrity of the wall assembly.

        http://rdh.com/wp-content/uploads/2014/04/Masonry_Veneer_Support_Details___FINAL.pdf

    • Todd H.
      December 1, 2014 at 9:45 pm #

      Along the same lines, our group noticed efflorescence located in the atrium area. Obviously there are some issues with the wall performance.

      Perhaps the lack of thermal breaks has lead to water penetration that caused the efflorescence.

  7. Sam d.
    November 20, 2014 at 9:50 am #

    With regards to photo 1, we noticed a lot of efflorescence, especially under the windows, and we thought this was due to improper weep holes or flashing such that water was saturating the brick. There were other places where we saw efflorescence and even possibly subflorescence where water would have saturated the wall due to damaged or missing sealant joints. Much of the sealant was deteriorated and most likely due to be replaced.

    Like photo 2, we saw several locations where the sealant was squeezing out or falling out, which could be due to improperly sized movement joints.

    Our group saw the condition in photo 3, however we were unsure of the cause behind it. It was the only place where we saw such a large chunk missing out of the facade, which we thought was strange. It could have been caused by the freeze thaw cycle, especially since it’s fairly exposed on the corner.

    • mkev
      November 30, 2014 at 5:35 pm #

      Exposure is a possibility. Ask yourself, however, why only at this one location? Is there any other item that may be possible that is a unique combination of events or details?

      Improperly sized joints are half the issue. Did anyone check the spacing? You can get both existing size and spacing from the site. I taught all of you how to calculate the size or spacing. You should all be able to comment in more detail on the size / spacing situation with a quick calculation.

    • Tyler P
      December 1, 2014 at 8:15 am #

      Sam, when my group was looking at the drawings we did noticed the improper weep holes and flashing. There were some stories of the building that the section did not even call out flashing, which made us believe that it may have not even been installed at all. Also, we noticed there were some area where the weep holes let out below grade. I don’t know if this is typical but it just seems like it isn’t correct.

    • Julia H
      December 1, 2014 at 6:07 pm #

      Though we did hypothesize on freeze-thaw cycle causing the failure from photo 3, I did later realize that brick occasionally shears off on the corners when expansion joints are not properly spaced, as Professor Parfitt’s comment mentions. If there are two joints too close to the corner on either side, this problem becomes more wide spread.

      Unfortunately we did not check the joint spacing on either side of the spall, but like Tyler’s group, we did notice that many of the weeps were improperly spaced.

      We believed that the blocked and improperly spaced weeps could have lead to greater water infiltration within the wall in photo 1. Though we didn’t do a full spacing calculation, by simply counting the number of bricks between weeps were were able to notice the spacing error.

  8. Adam J.
    November 20, 2014 at 1:10 am #

    As shown in Photo 1, there is a discoloration of the brick at each approximate floor level. The discoloration causes the brick to turn dark, most likely signifying water saturation. Significant water presents in the brick is evident in Photo 3, which during a freeze cycle was the most likely cause of the brick face splitting off. A more detailed investigation needs to be conducted in order to verify this assessment

    The typical detail of the shelf angle on A-16 shows a 3/8″ angle and allows for an addition 1/4″ clearance from the lower brick. The structural drawings were not included with the provided drawing set, therefore it is impossible to determine, without further investigation,if a 3/8″ angle was installed for the relief angle. In the case of a heavier angle, the 1/4″ clearance would be reduced. This could couple with water mitigation issues which would cause the angle to oxidize. There is a chance that the angle expanding due to the oxidation is applying excessive stress to the brick in the area of the relief angle.

    • mkev
      November 30, 2014 at 5:26 pm #

      See also my comments to Todd. I agree there is likely a problem with the angle but why only at the corner? That might be the clue for the additional possibility.

  9. Todd H.
    November 20, 2014 at 12:17 am #

    Many of the walls at the stairs and various site walls appeared to lack proper detailing to prevent water penetration. They typically lacked proper flashing, which had allowed water to penetrate, and led to brick spalling, capstone heaving, and other problems. The stairs on the east side appeared to have been fixed at some point, as flashing was visible beneath the capstone.

    Our group noted the condition in Photo 3, which occurs right above a horizontal joint. We hypothesized that is occurred due to improper detailing at the joint leading to water penetration, that eventually caused the brick to split off. However, we were unable to determine a definite cause.

    • mkev
      November 30, 2014 at 5:23 pm #

      If it is right above a joint, consider the possibility that the joint is not working correctly. Mortar in the joint? Improper gap restricting the shelf angle deflection? The fact that it is at a corner above a joint line also presents one other possible reason. Anyone have additional ideas / comments on this one?

      • Sam d.
        December 1, 2014 at 9:44 am #

        The corner may be slightly more exposed to the weather and thus slightly more likely to have moisture troubles. The shelf angle may have been exposed to water such that it corroded, expanded, and caused a stress fracture that eventually caused the brick to fracture off.

        • Caroline K
          December 1, 2014 at 3:00 pm #

          I also noticed that the head joints appear to be very wide in that area of the wall. Also, the brick breaks in a fairly clean vertical line at the corner side. These may be indications of improper angle detailing and horizontal movement of the wall on the left side of the photo.

          If an angle was provided at the horizontal joint, the size of the joint does not appear to be big enough to accommodate the angle and allow for expansion. There also needs to be spacing between shelf angles to allow for their expansion. If no spacing was provided or there isn’t enough space in the horizontal joint to allow for vertical brick expansion, the expansion against an unmoving angle could have caused stress in the brick resulting in the spalling.

          Part of the vertical expansion joint close to the brick spall seems to be cracked. This could indicate the issue is related to the joint. Assuming a 1/2″ expansion joint, the spacing of joints should be about every 23′. Can anyone verify if the spacing was provided on the wall opposite the one with the joint?

      • Nick D
        December 1, 2014 at 2:34 pm #

        Would the other problem be caused by expansion of the brick? If the joint is not working properly and the two walls that meet at the corner want to expand (lengthen), then the brick at the corner would be prone to popping off.

  10. Zach B.
    November 19, 2014 at 11:44 pm #

    One issue that our group noticed during our inspection of the drawings provided was that there appeared to be weepholes that drained out to below grade. the detail was 1/A-16. Is there a reason it was detailed this way, or is this a mistake in the drawings?

    • mkev
      November 30, 2014 at 5:20 pm #

      Probably just a poor choice. The easy place for the weeps is at the brick support shelf and the architects sometimes want that below grade so that there is no foundation wall showing, just brick. I will look at that detail to see if there is any other reason but they likely could have ended the cavity higher. Then again, that might have created a thermal break. Anyone else look at this and have a suggestion or reason???

    • Sam d.
      December 1, 2014 at 9:58 am #

      According to the 2009 IBC, “Flashing and weep holes in anchored veneer shall be located in the first course of masonry above finished ground level…”:

      http://publicecodes.cyberregs.com/icod/ibc/2009/icod_ibc_2009_14_sec005_par008.htm

      So according to code, weep holes shouldn’t drain below grade. I’m not sure how to know if it’s a mistake in the drawings without digging out the ground to see if there are weep holes below grade or not.

  11. Shuvrajit G
    November 19, 2014 at 11:09 pm #

    One of the prevalent failures I found was the sealant failures throughout the building. I spotted a few cases of adhesive failure, spalling failure , corner joint failure. Also some of the outside staircases had cracks in the concrete because of rust in the reinforcing bars.

    • mkev
      November 20, 2014 at 10:39 pm #

      I will let someone else in the class comment back on the rust situation and why it is occurring. I certainly agree that the sealant in general is in poor shape in many places and in need of replacement.

    • Nick D
      December 1, 2014 at 2:25 pm #

      The rust on some of the outside staircases is probably due to the bars being placed with not enough clear cover. In one condition on the southeast side of the building we could physical touch one of the bars!

      • Shuvrajit G
        December 1, 2014 at 9:42 pm #

        Nick,

        The reinforcing bars in the stairs are placed almost at the middle of the section. So there is at least 3 inches of clear cover to the reinforcing bars in the outside staircases. In my opinion the reason for the rust in the reinforcing bars is probably due to the inferior quality of the concrete.

        We also noticed there were rust stains in the nosing of the east entrance stairs, the reason for the rust is probably due to insufficient clear cover. It looked like the nosing for the east entrance staircase had been repaired recently.

        • Zach B.
          December 1, 2014 at 11:18 pm #

          Shuvrajit,

          I believe Nick is correct in that the bars were not constructed with a large enough clear cover. This could be an error on the contractor’s end. The detail you are looking at shows the clear cover for the side cast on the earth, which would be 3″. Concrete exposed to weather would only need a clear cover of 1 1/2″-2″ depending on the bar size (ACI 318-11 Section 7.7.1).

    • Yewande A
      December 1, 2014 at 6:07 pm #

      In addition to Nick’s comment, some of the rust is likely due to corrosion of metal which resulted in staining of the concrete stairs. My group noticed some areas had hairline cracks with visible rust stains. It seemed to me that the rust seeped through the cracks, the corrosion of the reinforcing bars would lead to expansion of the cracks and the concrete loses its bond with the steel reinforcing bars and could result in spalling of the concrete.

  12. Tyler P.
    November 19, 2014 at 9:11 pm #

    One thing that I noticed while doing our inspection was that there were a lot of issues that involved issue with the sealant. In some areas, we noticed that there was no sealant underneath the flashing allowing water to penetrate into the walls easily. There were also areas were the sealing was starting to peel off and needed maintenance to ensure that water penetration does not happen. There were also a few area where it seemed as if the sealant was too strong and actually caused the bricks to spall.

    • mkev
      November 20, 2014 at 10:37 pm #

      That could be a case of the joint being too small in general and not allowing the movement of the exterior brick to take place putting pressure on the masonry.

  13. Caroline K
    November 19, 2014 at 3:51 pm #

    One of the common themes our team noted were poorly constructed or missing waterproofing details which likely caused much of the brick spalling and subflorescence found. Many joints filled with cracked sealant, like in photo 2, and poorly placed weep holes were present. The link below discusses proper weep hole placement:

    http://www.masonryconstruction.com/Images/Installing%20Weep%20Holes_tcm68-1374806.pdf

    Weep holes were detailed at 2′-3″ on center, rather than the suggested 16″ mentioned in the above link (detail A on page A-16). Additionally, many of the weep holes were clogged with mortar, making them completely ineffective.

    Flashing that was sealed at the top, preventing the runoff of water, was also found by the base of the south side building by the doorway.

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