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  1. Canuck67

    Cold Joint in Pad Footings

    I would say pull it out. If you let them away with this, what will the contractor want to talk you into next .... Time to set the tone at the footing stage so that all construction above can be completed according to good construction standards. In my opinion, if they want to save the blob of...
  2. Canuck67

    Horizontal cracks in column under ramp

    Difficult to tell from the photos, but looks like it may be a cold joint. Inadequate vibration during placement combined with a time lag between successive layers of concrete being placed in the column/wall. Early removal of forms could have also contributed.
  3. Canuck67

    Rebar Corrosion

    I do not have any data from measuring such bars that I have seen in the past. Thinking back I likely have seen some bars with maybe 20% loss of section in the horizontal direction and 75% loss of section in the vertical direction. We generally did not measure as we would A) assume essentially...
  4. Canuck67

    Rebar Corrosion

    ajk1, I have seen similar many times, where the existing corroded rebar appeared to be flattened. I can only guess at a reason. In some cases, after the concrete spalls, the top of the bar remains exposed for a length period while the sides and underside still have some additional protection...
  5. Canuck67

    Pole Foundation

    In my area they augur the holes for the poles slightly oversize and then after setting the pole in place they fill the remainder of the hole with limestone screenings which compact very well and generally provide good load transfer from the pole to the surrounding undisturbed soil.
  6. Canuck67

    Pre-Fabricated Wood Roof Truss Long Span

    Within the last year we became aware of a project in our area with 60' span trusses (in a snowy area with 50psf snow load). Contractor was not aware and/or ignored the requirement to have a person/engineer knowledgeable in long span wood truss erection and guess what .... after erection of about...
  7. Canuck67

    Full Snow + Live Load

    For reference, the Canadian Code would look at the following load combinations: (there are other combinations to consider, but these are the most applicable to this situation) 1.25D + 1.5L + 0.5S or 1.25D + 0.5L + 1.5S whichever produces the most severe loading case. This would be considered...
  8. Canuck67

    Green Roof Structures

    There should be a properly designed drainage layer underneath the 'living' layer and immediately above the waterproofing layer. The drainage layer should allow for free flow of water towards a drain, or off the side of a sloped roof. There are many products on the market that provide this...
  9. Canuck67

    Sawcutting Control Joints

    I am looking at the design of a concrete slab-on-grade that is approximately 40'x40' in plan dimension. The final finish is specified by the architect to be polished concrete, therefore final appearance, cracking, etc... must be controlled as much as possible. In order for the control joints to...
  10. Canuck67

    Green or Kiln Dried Heavy Timbers?

    The heavy timber framers we work with exclusively use green material and most often white pine. It is easier for them to work with when green and cheaper to purchase green vs. kiln dried. Any suggestion that they use kiln dried material to fabricate their heavy timber framing was met with flat...
  11. Canuck67

    Six Story Wood Frame Construction: Tips & Resources

    Kootk, I unfortunately cannot elaborate, that comment was attributed to the presenter in the Woodworks seminar (Thomas Leung), a structural engineer from B.C. who is part of the committee on tall wood structures and also structural engineer for quite a few of the initial tall framed wood...
  12. Canuck67

    Reconnecting new flat slab to existing column

    I agree that drilling through 30" spirally reinforced columns is not ideal, can be difficult depending on rebar congestion, but is an option. I guess I am always the optimist in hoping that the existing rebar has minimal loss of section, because it makes things much easier. I am interested to...
  13. Canuck67

    Reconnecting new flat slab to existing column

    Typically, during demolition the structural slab is sawcut approximately 3'-0" away from the column face (and walls). Once the main portion of the slab has been removed (usually via sawcutting and removing slabs), the remaining concrete around the columns and walls is jackhammered. This removes...
  14. Canuck67

    Six Story Wood Frame Construction: Tips & Resources

    I have attended a couple of the Woodworks seminars on tall wood buildings. There are lots of details to consider, many of which you have mentioned. The presentation by Thomas Leung, structural engineer for many in the B.C. region certainly reinforced the complexity of the lateral analysis (i.e...
  15. Canuck67

    concrete delamination detection

    ajk1, Without steel in the thin slab, there can't be a delamination. However, there can be a delamination related to corrosion of the top steel in the ribs that affects the adjacent thin slab. The delaminations over the ribs should be quite pronounced. Perhaps for some training, identify...
  16. Canuck67

    concrete delamination detection

    ajk1, Not sure about GPR, but I will add this comment. I have sounded many square feet of waffle slab. An experienced person will have no doubt as to whether it is a thin slab or delamination. Yes, the sound is different between the rib and the pan, however, a delamination is yet again...
  17. Canuck67

    Wall of Windows (Part II)

    XRC, Code in Canada (Ontario) calls for l/180 for drywall and exterior finishes not susceptible to cracking, and l/360 for brick/stone veneer on wood studs. However, beyond Code, there are exterior stucco systems that specifically call for l/600 deflection limits in their product literature.
  18. Canuck67

    Wall of Windows (Part II)

    Medeek, I am not sure your spacing for your 2x8 studs, however, if at 16" o/c, this could be reduced to 12" o/c, or I have also used 2 ply studs @ 16" o/c or 2 ply studs @ 12" o/c. While I have used steel columns in the past, I am hesitant to do this unless you can get sufficient insulation...
  19. Canuck67

    Balcony Collapse in Berkley, CA

    I agree with gte447f. I am all for supplementary reviews, however, a meaningful review would include dismantling the architectural finishes which is rarely done during periodic visual structural reviews. Perhaps for critical components, the architectural finishes would have to be thought out in...
  20. Canuck67

    Splicing Pre-Engineered Wood I-Joists

    Boo1/Msquared48 - Thank you, Joist manufacturer contacted and very hesitant to comment on any splice detail, however, I have been referred to more senior personnel and await their phone call. Signious, I am in Southern Ontario, therefore a report from Southern Alberta would be very interesting...

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