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  1. #1
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    Default 2x2 framing and cmu's

    I went by the jobsite yesterday to do an ongoing construction insp. Masons are working, no admix or grout anywhere on the job. Even though I had an initial meeting with the Bricky before he started and told him I would be specifically looking for admix, grout and a few other things.
    But that's not what this thread is really about.
    My question is whether EB builders in your areas are also doing the same scummy thing I am about to describe or if this is a local problem.
    CMU/Brick shell building. Take 2x2 put some construction adhesive on the back of it, use nail gun to nail 2x2 onto CMU, some nails go into mortar joints, some nails hit block, some blocks fracture some don't. Perimeter walls framed.
    I run into this all the time and call it out every time. Of course builder states, Is' OK, no problem, inspector too picky.' Or something like that. I explain the problems to the clients, some have demanded it be changed others just live with it.
    Is this local or do you guys also see this around the country?
    Just curious, Markus

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  2. #2
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    Default Re: 2x2 framing and cmu's

    Quote Originally Posted by Markus Keller View Post
    I went by the jobsite yesterday to do an ongoing construction insp. Masons are working, no admix or grout anywhere on the job. Even though I had an initial meeting with the Bricky before he started and told him I would be specifically looking for admix, grout and a few other things.
    Markus,

    You've lost me there.

    Is a specific admix specified in the specification (few residential plans have specifications to begin with), or in the general notes (many residential plans do not have many general notes either)?

    If not, why are you asking for something which is neither required nor specified (which would make it required)?

    That's where I am lost.

    By 'no grout', what are you referring to? Grout for what?

    CMU/Brick shell building. Take 2x2 put some construction adhesive on the back of it, use nail gun to nail 2x2 onto CMU, some nails go into mortar joints, some nails hit block, some blocks fracture some don't. Perimeter walls framed.
    You mean they are using 2x2 instead of 1x2? That's a good thing. However, are the 2x2 PT?

    What kind of nails are they using that fracture the block?

    I explain the problems to the clients, some have demanded it be changed others just live with it.
    Would you explain precisely what you are talking about and what problems you explain to your clients?

    Jerry Peck, Construction / Litigation Consultant
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  3. #3
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    Default Re: 2x2 framing and cmu's

    Jerry, to further explain ...

    - A water repellant admix such as 'Rheopel' is required by our Code (by reference) to be used as part of the mortar mix on the CMU/brick builds
    - All cmu cells containing rebar are to be filled with grout, not mortar.
    I had to negotiate and defend a client in court a couple years ago on a case involving these items where the city insp was stopping the job because the mason wasn't doing these things. Our Code does not spell out these requirements but references the masonry institute standards that do. From my discussions, that seems to be where at least part of the problem originates. Assuming the mason reads the Code (huge assumption) he doesn't see those items stated and stops. It took me a while to track down the actual references and sift through to get the info the city mason insp was citing. (Of course he wasn't willing to provide the doc's himself.
    - grout and admix are stated on the stamped plans
    - the 2x2's aren't PT
    - the plans call for R19 insulation at exterior walls, as part of the Green building requirements and plan approval. You can't get R19 in a 1.5" cavity with batts and from what I know about spray on insul (limited) I think R19 needs 3-4" cavity
    - Nails- regular 3 1/2" paslode/bostitch framing nails
    - As for the CMU fractures- I'm not talking about the entire block mind you. Just a quarter/half dollar sized area around where the nail hits, that dimple of block that breaks away and would fall to the floor if the wood wasn't keeping it in place. Know what I mean?
    As far as concerns:
    - nails that break cmu at entry have no hold; nails likely to rust and have diminished hold, cmu is porous/not dense at points providing little holding power for a smooth nail
    - glue detaches from cmu, sometimes before construction is done or at some point later. I have found (field assessment) that this seems to be due to temperature when applied, dust on block and moisture levels of block during application. Some of the 2x2's I've checked on jobs are on the cmu really solid, others could be pulled off by a kid.
    - electricians tend to chop the crap out of the 2x2's; client ends up with pieces of wall structure
    - Have inspected near finished and finished drywalled walls of such construction that have evident pushback; The 2x2's will detach. When, how many? Who knows but is that the kind of construction you want Mr. Owner.
    - Inability to provide even R13 insul
    - Do NOT recommend hanging a plasma or anything from such wall
    - if (I know it's a big IF) water seeps into wall gets on the nails, that moisture will most likely get transferred into the drywall
    The better way to frame this out is to run a 1 5/8" track at the floor and ceiling and insert the 2x2's. It's easy, less labor intensive and doesn't cost anymore. It also allows you to pull the wall away from the cmu to provide insul and run piping. I used to do it all the time.
    Let me know what you think, Markus

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  4. #4
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    Default Re: 2x2 framing and cmu's

    Quote Originally Posted by Markus Keller View Post
    It also allows you to pull the wall away from the cmu to provide insul and run piping.
    I'll have to read through your post again when I get back, but, the above creates big problems trying to firestop that wall.

    Jerry Peck, Construction / Litigation Consultant
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  5. #5
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    Default Re: 2x2 framing and cmu's

    Quote Originally Posted by Markus Keller View Post
    Jerry, to further explain ...

    - A water repellant admix such as 'Rheopel' is required by our Code (by reference) to be used as part of the mortar mix on the CMU/brick builds
    If it says so, then, yes, it is required.

    - All cmu cells containing rebar are to be filled with grout, not mortar.
    But that is not where you stop, and, in fact, if that is all you are inquiring about, there is no need to even inquire about that.

    The grout is required to be consolidated in 5 foot lifts maximum, then re-consolidate the first lift when consolidating the second lift, then top it off and re-consolidate the second lift.

    If pump mix is used instead of grout (neither is 'mortar'), then consolidation is vastly more important as pump mix will likely not make it to the bottom and / or fill all the voids. Using pump mix with consolidation may be an effective replacement for grout and not consolidating, however, I said 'may' as "grout" is "required", not "pump mix".

    It took me a while to track down the actual references and sift through to get the info the city mason insp was citing. (Of course he wasn't willing to provide the doc's himself.
    ACI 530. That's the reference and the requirements.

    - grout and admix are stated on the stamped plans
    Again, that makes it required.

    - the 2x2's aren't PT
    Not good. I guess they figure that the wood is not actually touching the block - because of the construction adhesive?

    - Nails- regular 3 1/2" paslode/bostitch framing nails
    Not using the correct nails for the correct use is a BIG problem all over with everything. A framer picks up a nail gun and "assumes" it will work for and on everything and anything.

    There are many things which those gun nails are not supposed to be used on or for, but are. Just one example is Simpson straps. There are many types of Simpson straps in which gun nails are only allowed if ... *IF* ... the gage (shank wire size) and head size are the same as the specified nail, typically a 16d. Many guns will shoot 'an equivalent' (so they say) of a 16d, but when you read the Simpson documentation the only 'equivalent' is a nail of the same gage and head size.

    A 16d common has a shank size of 8 gage (0.162 inch), shank length (exclusive of the point) of 3-1/2", with a head size of 11/32".

    A '16d gun nail' is only 0.128 in diameter ... oops - that does not cut it when 0.162 is specified (16d common)

    - As for the CMU fractures- I'm not talking about the entire block mind you. Just a quarter/half dollar sized area around where the nail hits, that dimple of block that breaks away and would fall to the floor if the wood wasn't keeping it in place. Know what I mean?
    As far as concerns:
    - nails that break cmu at entry have no hold; nails likely to rust and have diminished hold, cmu is porous/not dense at points providing little holding power for a smooth nail
    All solved with the right nail for the right use.

    - glue detaches from cmu, sometimes before construction is done or at some point later. I have found (field assessment) that this seems to be due to temperature when applied, dust on block and moisture levels of block during application. Some of the 2x2's I've checked on jobs are on the cmu really solid, others could be pulled off by a kid.
    All solved with applying the structural adhesive correctly.

    Hmmm ... isn't that what keeps HIs in business, that the work *is not done correctly*? or should it be

    - electricians tend to chop the crap out of the 2x2's; client ends up with pieces of wall structure
    Any you expect that to be any different than regular studs, floor joists, ceiling joists, trusses? Why?

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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  6. #6
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    Default Re: 2x2 framing and cmu's

    Hey Jerry, I barely remembered it was AC 5 something or other. I do remember about the 'lifts' because that was another big issue in the case a couple years ago.
    I do tell my client about the importance of proper procedure during builds, usually their eyes glaze over or flat out tell me they aren't interested in the details. "That's what we have you here for' is a common response. Not a problem for me.
    As far as talking to the masons about 5' lifts and procedure, I do it but it's a waste of breath. Mention a 5' lift procedure to an EB and they think I'm talking about one of their comrades at the Olympics.
    It is amazing how a nail gun can be used for anything. Just like a drywall screw for building stairs. I usually see the newest, youngest guy glues/nailing the 2x2's onto the cmu. I think they just see it as grunt work.
    Update-
    1- mason claims admix isn't needed, overkill because he mixes a strong mortar mix (yeah I know, I laughed too when I heard it)
    2- swears he's using grout; even though I walked the entire site and mix area and didn't find any bags; mason showed client a few empty bags yesterday afternoon (I wonder where those came from)
    Anyway still curious as to whether guys are nailing 2x2's directly onto cmu in other parts of the country of if it's a local thing.
    Thanks, Markus

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  7. #7
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    Default Re: 2x2 framing and cmu's

    What is "EB builders"?
    Forgive my ignorance, but very little CMU construction here outside of commercial and most of that is tilt wall.
    Slab foundations and wood frame and brick veneer construction is by far the method of construction here.

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  8. #8
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    Default Re: 2x2 framing and cmu's

    EB's = East Blockers, guys from former Soviet satellites, think cold war
    Fairly common term around here, since there are so many of them. For fast paced small to medium sized condo development cmu/brick builds they are mostly it.
    Of course no one ever admits to speaking english, when an inspector shows up. I have managed to get friendly with a few over the years. Some of the stories are rather interesting. To some extent, under the context of immigration, wages, and support back home, for some it is equivalent to modern day slavery.
    There are still Irish and others around doing masonry but they usually are doing different, better types of jobs that I don't generally inspect. Not that all EB work is bad, it isn't. It's just that it usually lacks refinement. knowledge of details, etc. that make a build Code/Standard compliant and better.

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  9. #9
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    Default Re: 2x2 framing and cmu's

    Quote Originally Posted by Markus Keller View Post
    Update-
    1- mason claims admix isn't needed, overkill because he mixes a strong mortar mix (yeah I know, I laughed too when I heard it)
    Yeah ... ... he *should* know that he should be using the weakest mortar for the job - weakest mortar = greatest bond / strongest mortar = weakest bond ... and "bond" is what the mortar is for. Sheesh.

    2- swears he's using grout; even though I walked the entire site and mix area and didn't find any bags; mason showed client a few empty bags yesterday afternoon (I wonder where those came from)
    Unless he is mixing with a small mixer on site and grouting the filled cells, by hand, the grout is usually from a ready mix concrete plant and is pumped into the cells - you would not see an bags of grout on site.

    At least that is how they do it wherever I've been.

    Anyway still curious as to whether guys are nailing 2x2's directly onto cmu in other parts of the country of if it's a local thing.
    They do here, and in South Florida - but not with big honkin' nails which blow the block out. You might get a few blowouts from the nails, but not many.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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  10. #10
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    Default Re: 2x2 framing and cmu's

    Jerry, on these smaller Condo builds, 3-18 units, I've never seen anything pumped except the foundations and basement floors. When they have Grout it's always a skid of it, mixed as needed.

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