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  1. #1
    Rich Mackowsky's Avatar
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    Default Attaching floor joists to existing foundation - is this acceptable?

    We are adding on to the back of our house - sunroom on one end, full bath/hallway/closet in middle, bedroom on other end - 525 sqare feet. The foundation for the addition is three sided, with the fourth side being the existing foundation. There are two support foundation pillars under the middle section, but none under the sunroom or bedroom (both are 15 X 15)

    The addition floor joists run perpendicular to the existing foundation, and thus needs to be attached to it. I was under there looking around, and noted that the the builder has nailed a 1 X 1 board to the existing rim board, and the floor joists are resting on that board. A couple joists are attached with hangers (simpson stong-tie) to the rim board, but most are not - they are just resting on the new 1 X 1 board.

    My question is - is this adequate? Is this an acceptable way to support floor joists? Should the support board be more substantial than 1X 1? Apparently it meets code, and it did pass inspection, but it scares me a little so I'm looking for some reassurance.

    I will try to take a few pics tonight and post tomorrow.

    Thanks in advance.

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    Last edited by Rich Mackowsky; 05-22-2008 at 06:38 AM.
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Code requires a minimum joist-end bearing is 1-1/2" but I'm not happy about the 1x1 nail-on leger your builder is using. I would insist on every floor joist having its own hanger and with a 15 foot span I hope he is using 2x12 joist for your addition. However, you said there where 2 new girder post piers installed and are they perpendicular to the direction the new joist are spanning? If so, the 15 foot span has been cut in half and 2x8s will work in that case. I recommend never using 2x6 and of course 2x4 are never allowed, or should never be allowed.

    Jerry McCarthy
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  3. #3
    Rich Mackowsky's Avatar
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    "Code requires a minimum joist-end bearing is 1-1/2"...does that mean the ledger has to be 1.5 X 1.5 minimum?

    They could be 2 X 2 - I'm going to go down there tonight and get more info and pictures. They're definitely not larger than 2 X 2. Does that meet code?

    I'll check on the joist size as well. Is 2 X 12 the code requirement for a 15 ft. span? The foundation pillars are not actually boards - they are square foundation pillars (cinderblock and brick), and neither of them is located in the two 15 X 15 areas in question. Basically there are two 15 X 15 areas whose only support are the three new foundation walls and the aforementioned ledger on the existing house foundation.

    The other concern is that it looked to me like the ledger is just nailed into the rim joist. Doesn't code require lag bolts?

    Thanks so much for your help.

    Last edited by Rich Mackowsky; 05-22-2008 at 06:38 AM.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Like Jerry Mc indicated, 1x1 (or 1x2, 1x4 or 1x6) is not adequate bearing (under the floor joists) for the ends of the joists because a 1x is actually 3/4" and does not provide the necessary 1 1/2" bearing. A 2x2 would not be adequate because it would be likely to sag and/or split. I would say that a 2x4 ledger would be too small as well and would want at least a 2x6 ledger. If you are still under construction, the framer may have used the 1x1 (or 2x2) to temporarily support the joists so that they line-up properly. But I would check to make sure that he/she installs properly sized joist hangers before the subfloor sheathing goes on. It sounds to me like the joists butt into the rim joist, which would be fine once the hangers are installed. If the joists are supported by joist hangers from a ledger that is attached to the foundation, the ledger should be pressure treated lumber and at least the same dimension as the floor joists. Since the joists are only taking the floor load and are not supporting walls or roof, nailing the ledger to adjacent wood framing may be OK as long as enough nails are used. Bolts would certainly be better, and would be necessary if anchoring into the foundation. The bolts should be placed between the center and the bottom edge of the ledger.

    According to my tables, 2x10 @ 16" centers is the minimum joist size, but it would probably be noticeably bouncy. 2x12 would be better. 2x12 would be necessary if the joist spacing was 24".

    Pics would help.

    Last edited by Gunnar Alquist; 05-21-2008 at 02:54 PM.
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  5. #5
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Just checked the plans - floor joists are 2 X 10. Subfloor sheathing (that's the same as floor boards, correct?) is already on, so it isn't temporary.

    "It sounds to me like the joists butt into the rim joist, which would be fine once the hangers are installed." - that is correct, but only a few joists have hangers on them. Do you suggest I put hangars on ALL the joists? Is that difficult to do now that the floorboards are on?

    I'm getting under there for some pics after dinner - will post them tonight.

    Last edited by Rich Mackowsky; 05-22-2008 at 04:26 AM.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Rick,

    Not a problem to do it from underneath. Just easier to do it prior to installation of the subfloor (yes, subfloor, sheathing and floor boards would be essentially the same).

    We will probably know better if hangers are necessary once you have some pics. I would have thought that joist attachment would have been specified in the plans that you have. Might be in a drawn detail or in the written specifications.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    You don't need joist hangers unless the plan calls for them (possibly for heavier loading). Using the ledger is an acceptable practice.

    From the 2006 IRC. (underlining is mine)
    - R502.6.2 Joist framing. Joists framing into the side of a wood girder shall be supported by approved framing anchors or on ledger strips not less than nominal 2 inches by 2 inches (51 mm by 51 mm).

    Also, I think we need to tread lightly on "designing" something with little information given, unknown species of wood, unknown load, etc., I believe it can get to be irresponsible of us to second guess what we do not know the particulars of.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    JP,

    Is that minimum code you are quoting there?

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  9. #9
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Just took some pics - working on getting them uploaded and posted. I really appreciate everyone's opinions and advice.

    Last edited by Rich Mackowsky; 05-21-2008 at 07:40 PM.

  10. #10
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Okay - the ledger is 2 X 2 (measures 1.5 X 1.5 with tape measure, so that's nominal 2 X 2 correct?). The joists are 2 X 10 (1.5 X 9 tape measure). Space between joists is 12.5. Joists are doubled up as seen in pics.

    There are 3 nails in the ledger per joist connection. The joists are also crossed nailed into the rim joist.

    Th only joists with hangers are the ones over the newly cut hole in the existing foundation (for HVAC, plumbing, etc.) There is one other joist with a hangar, and that one is below the bathroom.

    I have included a pic of the overall add-on, as well as a pic of the foundation before framing - the pillars I mentioned are visible.

    So - does this look acceptable? Is it possible at this stage to add hangars to all the joists? Is that even necessary?













    Last edited by Rich Mackowsky; 05-21-2008 at 07:42 PM.

  11. #11
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?








  12. #12
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    The ledger board is fine. You do not need to add joist hangers with a ledger board. Do yourself a favor and add some bolts to the ledger board and it will be fine.


  13. #13
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by David Banks View Post
    The ledger board is fine. You do not need to add joist hangers with a ledger board. Do yourself a favor and add some bolts to the ledger board and it will be fine.
    I think I'll let the builder add the bolts. What type of bolts should I ask him to put in, and how many?


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Never seen it done that way, but I am in CA and things might be done differently here for seismic reasons. I am rather surprised that it would be acceptable, but JP's IRC quote indicates that it is and David does not seem to have a problem with it.

    Simpson does make hangers for doubled joists and it would probably be not too difficult to bang the hangers in between the ledger and the bottom of the joist. .

    Bolting might split a ledger that small.

    What is the purpose of the pier in the middle? Does it support something heavy?

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    That support in the middle Gunnar may support a safe or a gun safe. I've seen those used for that in the past.

    rick


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Rich, I don't know what they are building in other parts of the country but in NC that floor framing looks fine from the pic's. Ledger boards are used all the time and these are attached with a min. of 3 16d nails per joist. The hanger I saw had all of the nail holes filled with nails as required,(shows the framer cares) many I see have open holes. Looks like the sill plate is treated wood. Good. Minor detail is the built-up girder has a single rather than a double joist hanger. Not a big deal in my book but probably not up to code. (note: I am not a CEO) I have never seen bolts in the ledger board and think spliting the ledger would be a concern.

    My vote is to give the builder a pat on the back and let him know you are watching with enthusiasm.


  17. #17
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Gunnar Alquist View Post

    Simpson does make hangers for doubled joists and it would probably be not too difficult to bang the hangers in between the ledger and the bottom of the joist.
    I was wondering about that. I may ask the builder to do that. Just for my info, if have to pay out-of-pocket for him to do this "above code" what would be a reasonable cost?

    Quote Originally Posted by Gunnar Alquist View Post
    Bolting might split a ledger that small.
    That's a good point. There are a couple places where the nails themselves have actually split the board a bit. Should I be concerned about that?

    Quote Originally Posted by Gunnar Alquist View Post
    What is the purpose of the pier in the middle? Does it support something heavy?
    No gun safe, LOL. Actually, I'm not sure. Looks like I'll be going down there again to find out.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Gunnar Alquist View Post
    Is that minimum code you are quoting there?
    Gunnar,

    Yes it is, and if one was to get into answering the question ...

    Quote Originally Posted by Rich Mackowsky View Post
    My question is - is this adequate?
    ... then doing so would require an engineer, who would step outside the minimum code ...

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  19. #19
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Vern Heiler View Post
    Rich, I don't know what they are building in other parts of the country but in NC that floor framing looks fine from the pic's. Ledger boards are used all the time.
    Are they typically the minimum size (2 X 2)?


  20. #20
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Jerry Peck View Post
    Gunnar,

    Yes it is, and if one was to get into answering the question ...



    ... then doing so would require an engineer, who would step outside the minimum code ...
    I don't know if that should concern me or not.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Gunnar Alquist View Post
    What is the purpose of the pier in the middle? Does it support something heavy?
    Those piers (there are two in that photo) look to be aligned with interior walls under the two roof sections and under load bearing columns under beams on which the rafters or trusses were set, probably to shorten the span to allow for smaller dimension beams.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Ledger is almost always 2x2.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I am about to step in it but I don't care.
    You guys clearly have very low standards when it comes to what is considered a 'good job'.
    2x2 ledger boards at one time were (and apparently still are) an acceptable and used method. I would throw a guy off my jobsite if he tried to build an addition support like that nowadays.
    - 2x2 pine in a crawlspace nailed to a wolmanized plate - over time with movement, humidity and age the 2x2 will rot and sag
    - depending on how wet or dry that (2x4) wolmanized plate that is laying on the brick wall was when the nails were driven into it - the nails will have more or less give to slowly allow the load to angle them down and out
    - in one of the pictures the joist nailing is very clear - nails are driven very close to the end of the joist, instead of another 1/2" back in order to go through the full width of the board and have some 'meat' around it
    - 15" span should be 2x12 to avoid bounce
    - what size bolts to use and other specific design questions - that's what architects and construction inspectors get paid for
    Am I speculating here? NO. I've jacked up and properly repaired jobs just like this 5-10 years after some lazy, jerk-off contractor did exactly what your contractor is doing.
    Why someone would still use this poor longterm method defies reason. This installation method will fail. The only question is when. It is not a proper longterm installation. I understand that some of you find it acceptable but experience does not allow me to.
    With that in mind.
    - Have you addressed venting of the crawlspace area?
    - Will the ground be covered with a vapor barrier or insulation board? I don't know anything about your region, so such questions must be answered by someone who does.
    Holding integrity of the 2x2 will be greatly effected by those criteria.
    Good luck, you'll need it.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Someone please say something to make me feel better about that last post.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Rich Mackowsky View Post
    Someone please say something to make me feel better about that last post.
    (referring to the post below)

    Quote Originally Posted by Markus Keller View Post
    I am about to step in it but I don't care.
    You guys clearly have very low standards when it comes to what is considered a 'good job'.
    Rich,

    Marcus is addressing one thing - " 'good job' ", others of us are addressing another thing - "code".

    "Code" is the (as I have frequently stated here and to my clients over the years) ... "Code" is the minimum crappiest one is legally allowed to build." and "code is not 'good', 'better', or 'best' building practices, 'code' is simply 'minimum allowable building practices'.

    Quote Originally Posted by Jerry Peck View Post
    ... then doing so would require an engineer, who would step outside the minimum code ...

    If you want "good", "better", or "best" building practices, you will need to contact a structural engineer, provide them with what you 'want' as far as livability goes (which would include things like: I'm going to be placing a 35 ton sculpture in this location and I do not want the floors to deflect at all), and then open your check book because you will truly be designing and building a "custom" home addition.

    Other than that, "acceptable" building practices are basically "code minimum" practices, and most homes you've probably been in are "code minimum" (or even less, remember, "code" is the legal minimum, if the builder can get by with less, most will).

    Marcus raises some good and interesting points, however, there is nothing inherently wrong with ledgers, although I prefer hangers myself. There are many, many, many 50-75+ year old houses still standing which used ledgers. Even if you built as Marcus suggested, I would not put much faith in new construction lasting as well as, and for the length of time as, old construction has lasted.

    It is a modern trend, basically started after WWII when all the troops came back and wanted housing, which consists of building things 'which will do' instead of 'which will last', and, the even more modern adaptation of that process is actually called "VE" (which stands for "value engineering"). "Value Engineering", as I explain it in reality, is "engineering the value out of it", leaving you with 'just enough', which is not really "value", but 'just enough'.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Rich, are you building an addition or a national monument that future civilizations will marvel over?

    Look at the construction of the rest of the house. Is it built to a similar standard? Go under some friends homes and see if they are falling down. Jump on the floor and see if it deflects.

    Charlotte is not the oldest city in the US but have homes built in the late 1800’s, some I have inspected did not even have ledger boards, still standing!

    Some of what has been posted borders on fear mongering. It is easy to suggest the maximum when it is not your wallet.

    If you are going to park your SUV in the bedroom, you need to get a PE to draw something up.


  27. #27
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Vern Heiler View Post
    Rich, are you building an addition or a national monument that future civilizations will marvel over?
    LOL - we considered that, but I would have had to work overtime.

    Quote Originally Posted by Vern Heiler View Post
    Look at the construction of the rest of the house. Is it built to a similar standard? Go under some friends homes and see if they are falling down. Jump on the floor and see if it deflects.
    The existing home does not use ledger boards - the joists are directly over the foundation, as are the joists in the other three walls of the add-on. So I don't know if that comparison provides me any insight. I guess a better comparison would be a deck, since I believe that most attach with ledger boards, although I know some attach with vertical hangers. Maybe I'll check out the neighbors deck to see how it's connected. Would the load bearing of a deck be comparable to our addition? I would think the addition would need to bear more load, but then again there's no wall or roof to support (since the roof is attached to the house - is that correct?) so is it correct to kind of consider the addition as one big deck when it comes to load bearing requirement? To be honest, if I were building a deck, I would still be nervous about the 2X2 ledger and would probably pay to add vertical hangars for peace of mind.

    I do understand and appreciate your point, and that is why I posted here - to get the opinions of those who know far more than me about this issue.

    Last edited by Rich Mackowsky; 05-22-2008 at 06:46 AM.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Rich Mackowsky View Post
    To be honest, if I were building a deck, I would still be nervous about the 2X2 ledger and would probably pay to add vertical hangars for peace of mind.
    Rich,

    There is your answer.

    For your comfort zone to be reached, you would like the builder, required or not, to install joist hangers on each joist. That will not be a problem for single, double, or triple joists, but if you have any wider then that, you might not be able to find a hanger for it.

    You also previously asked about cost, that varies a lot from area of the country to area, so, again, the answer to your question lies in 'your comfort zone'. If your builder says 'It will will cost $Xgazillion.', then you might say to yourself 'I can do that over a few weekends after I move in.', and, it may likely never get done, meaning that your comfort zone was comforted after you moved in and 'it all felt okay'.

    If you want to build a Saturn V launch pad for a slab, do so, but the cost of concrete and steel in China might go up.

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  29. #29
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Jerry Peck View Post
    Rich,

    If your builder says 'It will will cost $Xgazillion.', then you might say to yourself 'I can do that over a few weekends after I move in....
    Is it going to be very difficult to wedge the hanger between the joist and the ledger at this point? Will it damage the joist or the ledger? Looks like I can buy the hangers for $2 each online, so it's just labor costs versus the time/aggravation of doing it myself.

    Last edited by Rich Mackowsky; 05-22-2008 at 08:14 AM.

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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Those 2x2 ledgers are whimpy at best and the crawl space vent openings in the foundation stem wall look to low to me? After landscaping (adding topsoil) you are going to have to build little “areaways” around those vents. I also would ask why the new addition’s joist had to be installed perpendicular to the existing floor framing and needless to say that brick foundation would never fly in seismic territory. Any steel rebar in that CMU foundation?

    Frankly, I’m with Marckus on this thread, all the way even without knowing where this project is being built and fully agree with Mr. Peck that following the code to the letter is about the lowest form of construction technology there is. One should thoroughly pay attention to the word “minimum” when it comes to those that loudly proclaim they always “build to code!”

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  31. #31
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Jerry McCarthy View Post
    Those 2x2 ledgers are whimpy at best and the crawl space vent openings in the foundation stem wall look to low to me? After landscaping (adding topsoil) you are going to have to build little “areaways” around those vents. I also would ask why the new addition’s joist had to be installed perpendicular to the existing floor framing and needless to say that brick foundation would never fly in seismic territory. Any steel rebar in that CMU foundation?

    Frankly, I’m with Marckus on this thread, all the way even without knowing where this project is being built and fully agree with Mr. Peck that following the code to the letter is about the lowest form of construction technology there is. One should thoroughly pay attention to the word “minimum” when it comes to those that loudly proclaim they always “build to code!”
    Just to clarify - the new joists are actually parallel to the existing floor joists. Is that a necessity or could they have been installed perpendicularly? Seems to me that would elimnate the need for a ledger board since the new foundation would support the joists on both sides. Is there something in the building code that says that they can't be installed perpendicularly? Even if it's not against code, is there a reason NOT to install perpendicularly if that would be the stonger option?

    BTW, I'm in North Carolina Raleigh area.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Rich
    Most builders opt to span the shortest span. The biggest mistake is under-sizing floor joist in that if you have ever walked across a floor and heard the China and/or any other small accoutrements rattle you understand my meaning. However, some folks may like the trampoline effect in a bedroom?

    Jerry McCarthy
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  33. #33
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Jerry Peck View Post
    It is a modern trend, basically started after WWII when all the troops came back and wanted housing, which consists of building things 'which will do' instead of 'which will last', and, the even more modern adaptation of that process is actually called "VE" (which stands for "value engineering"). "Value Engineering", as I explain it in reality, is "engineering the value out of it", leaving you with 'just enough', which is not really "value", but 'just enough'.
    Value engineering is the process of transforming designs and specs that have "best practices" into ones that are "code minimums".

    2x2 ledgers or joist hangers can do the job, provided both are properly fastened. Ask the builder for a price to retrofit some joist hangers. If the price is within your comfort zone and would give you peace of mind, go for it.


  34. #34

    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Even we build a little differently in the Chicagoland area (the ledger would never fly in most areas around here), I do think the floor structure is fairly solid with the joists toe nailed to the rim and on a ledger.
    If you want to add a little more stability (and for your peace of mind), try these; one on either side of the joists.

    Simpson Strong-Tie ANGLES REINFORCE/SKEWABLE (Priced Per Each) - Fastening Systems Inc.


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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Brandon Chew View Post
    Value engineering is the process of transforming designs and specs that have "best practices" into ones that are "code minimums".
    Brandon,

    The problem with value engineering that I see is that most often the end design no longer meets "code minimums".

    That said, there is "value" in "best practices", and that "value" has been engineered out in an effort to reach the bottom ("code minimum"), thus, the value has been engineered out.

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  36. #36
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Jerry Peck View Post
    The problem with value engineering that I see is that most often the end design no longer meets "code minimums".
    My statement about value engineering was meant to be tongue-in-cheek, but I forgot to add the smilie.

    You and I both know that code represents the legal floor that the designer can "build down" to. Other than the occasional gaffe (which would be covered under E&O as long as the firm remained insurable), any firm doing "value engineering" that took a code-compliant design below code would be buying a one-way ticket out of business on the "gross negligence" train. I think that your statement, as it pertains to design, is an exaggeration of reality. We also both know that the best laid plans of designers and manufacturers often go awry during the build & installation phase -- it's what keeps guys like us gainfully employed.

    Quote Originally Posted by Jerry Peck View Post
    That said, there is "value" in "best practices", and that "value" has been engineered out in an effort to reach the bottom ("code minimum"), thus, the value has been engineered out.
    I think we both agree that quality comes at a cost. Thus another way of looking at "value engineering" is the process of turning a quality home into the cheapest home that the builder can legally get away with building. This statement by me is an exaggeration too. The floor is really "while still meeting the client's requirements" -- not all clients want the floor to be all the way down to "code minimum".

    My personal preference is to build things to last, over building them cheap. I don't do "value engineering" because I wouldn't want the liability associated with taking the original designer's work product and then changing it to shave cost. I think that's an issue that is best handled between the original designer and the client during the design process.


  37. #37
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Brandon,

    I'm not saying that value engineering taken to below code is done intentionally, just that the end result is often there.

    During the designs value engineering process many things are changed and redesigned, and sometime (more frequently than one would hope) some previous VE changes are not considered during subsequent VE changes, with the end result not meeting code.

    I agree that value engineering should be "an issue that is best handled between the original designer and the client during the design process.", it's just that sometimes 'cost' concerns overrun 'common sense' limits.

    Jerry Peck
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  38. #38
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Alright, no argument there. It's rare that a set of plans & specs, submitted for code review and approval, get approved without at least one round of comments and revisions. Also, since everyone can make mistakes, as more hands touch and re-work a design, more mistakes can be made.


  39. #39
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I want to thank everyone for their replies, opinions, advice. When I started this thread, I had no knowledge at all about floor framing, ledgers, etc. I just saw a 2X2 holding up my floor and thought - "Wow, is that gonna hold up?". My main goal was to insure that the current set-up was reliable and commonly used in my area. I now know, through this thread and discussion with my builder, that it was built properly according to local codes, and that it is a common way to build in this area. I also realize that there are other possible ways to strengthen the attachment. I'm still considering adding the Simpson A35 or LS50 framing angle (thanks for the link), but at least now I know that it's not NECESSARY but optional mainly for my own piece of mind.

    The important thing is I have a builder I trust completely who is open to communication at all times. I even sent him the link to this thread before discussing it directly with him. These guys have earned my trust and I believe them when they say this is common and accepted practice in this area. But again, thanks to everyone here I have a clearer understanding of the situation as well as other options.


  40. #40
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I have a similar floor system on my main floor using a 2x2 ledger. My joists are 2"x8" 16" oc. The span is approximately 10'. I currently have a 55 gallon fish tank against the oustside foundation wall in the house. I am moving up to a 90 gallon and am concerned about this ledger holding the weight. I have gone in and added joist hangers in the area where the tank will be, but want to be sure the floor holds the weight. Any suggestions?


  41. #41
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Your framing design meets (and even exceeds by a bit) the 40 lb psf standard. We'd need to know the footprint of the fish tank to be sure it isn't overloading the standard framing of floors.

    I'm thinking it's approximately 800lbs (720 of water plus and extra 80lbs of tank, cabinet, etc.) Therefore, it shoudl have a footprint of at least +/- 20 square feet. That seems bigger than most tanks I've seen but 90 gallons is pretty big.

    You might also call an aquariam store or manufacturer to determine if/when tanks exceed standard floor construction. I'd think somebody in the business would know.


  42. #42
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    The footprint of the tank is 48 1/4 long x 18 1/4 wide.


  43. #43

    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I personally would not be concerned with it as you say it is on an outside wall. If it were in the center of a span, I would worry about deflection. (my non- engineer opinion)


  44. #44
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Thanks. I do understand the 40lbs/sqft concept too, but isn't that considering the weight of the entire room? Minus people, the room has only a small table and chairs + the hardwoord floor covering.


  45. #45
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    If you have access to the underside you could just sister on some additional joists to the ones beneath the tank. Run them as close to each end as practica. If you can bear them on the same surfaces as the ones present, great. If not, they'll still help a great deal by stiffening the joists and preventing deflection.

    I agree with Brandon that it would most likely be okay but the deflection and movement might be a bit annoying. Supporting a static load (floor framing) is just so easy that I've just always over-built the heck out of it so there is no worry at all.


  46. #46
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I am actually thinking about drystacking a pier of cinder blocks placed on about six inches of gravel (digging out for the gravel). Then spanning a 4x4 across 4-6 of the beams in the area where the tank will sit to distribute any weight that might be applied.


  47. #47
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Kevin Bolick View Post
    I am actually thinking about drystacking a pier of cinder blocks placed on about six inches of gravel (digging out for the gravel). Then spanning a 4x4 across 4-6 of the beams in the area where the tank will sit to distribute any weight that might be applied.
    If you are going to do something like that, at least construct a proper footing and fill the blocks.

    The gravel will redistribute with the load and the support will not do much good.

    Additionally, you will have just created a hidden multi-lane expressway for termites to attack the structure from below.

    You do not want to create additional problems by trying to solve your other problems, and doing as you described will potentially create those other problems.

    Besides, when you go to sell and forget those are down there, your buyer's home inspector will (hopefully) write those up as 'What settling went on to cause these supports to have to have been installed? Contract a structure engineer to design appropriate repairs.' - or something to that affect.

    Jerry Peck
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  48. #48
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    Exclamation Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Rich Mackowsky View Post
    Okay - the ledger is 2 X 2 (measures 1.5 X 1.5 with tape measure, so that's nominal 2 X 2 correct?). The joists are 2 X 10 (1.5 X 9 tape measure). Space between joists is 12.5. Joists are doubled up as seen in pics.

    There are 3 nails in the ledger per joist connection. The joists are also crossed nailed into the rim joist.

    Th only joists with hangers are the ones over the newly cut hole in the existing foundation (for HVAC, plumbing, etc.) There is one other joist with a hangar, and that one is below the bathroom.

    I have included a pic of the overall add-on, as well as a pic of the foundation before framing - the pillars I mentioned are visible.

    So - does this look acceptable? Is it possible at this stage to add hangars to all the joists? Is that even necessary?










    Forgive me if this was already stated, but that 2x2 ledger probably doesn't have any structural reason to be there at all. Look at it - It's got about (2) nails under each joist. What holds the joists in place is the toenails and an occasional hanger as near as I can tell from the photos. Personally, I would never like to see a floor joist held up by toenails. A short rafter sure, but not a floor joist. People will be walking on this every day. The 2x2 "ledger" is probably only there to hold the floor joists in place while they were nailed.

    I also see (2) ply joists held up with single joist hangers. They strengthened the joist, but not the connection. What's the point of that? You know you can buy (2) ply hangers. They are cheap and you can get them at any Home Depot or Lowes.

    They really should have used a joist hanger at each joist. At this point I would look into retrofitting each joist that has no hanger with an angle clip. Each Simpson A35 gets you like 450# of capacity.


  49. #49

    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Hi MTG,

    Toe nailing floor joists is not allowed as a permanent support method. The options are to run the joists over something like the sill plate, using hangers, or that nailer. I agree that the nailer is likely not supporting much of those joists, but from what I know, it is required. Contractor's don't use the nailer method around here though.......... You can look at R502.6, R502.6.2 for details (sorry, I can't copy/ paste it) Here's OR's building code on- line based on the 2006 IRC: 2008 Oregon Structural Specialty Code

    Also, I think they only used the hangers at the opening that separates the crawlspaces, since a nailer would not work there. The cheaper the better, right??

    Last edited by Brandon Whitmore; 03-09-2009 at 06:36 AM.

  50. #50
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Mike, isn't the shear strength of a 16d common about 180lbs? With 3 per joist the ledger provides about 540lbs of support per ledger.


  51. #51
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    Smile Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by Vern Heiler View Post
    Mike, isn't the shear strength of a 16d common about 180lbs? With 3 per joist the ledger provides about 540lbs of support per ledger.
    The nail value you use depends on the species of the lumber and nail diameter. I see a stamp on the joist saying S. Fir which would have lower allowable values than say Southern Yellow Pine or Douglas Fir. Also it's been my experience that most framers use a gun nail which almost always has a smaller diameter than the common nail values shown in the National Design Specs. In practice a 3-1/2" long supposedly 16d nail often has a diameter equal to that of a 10d nail. If I had to guess, not having all the particulars, I would place the allowable nail value closer to 100# than 180#. Also remember that you are required to reduce the nail value for toenails by a significant amount - perhaps 1/3. Toenails must be driven at 30 degrees to the joist - how often is that not the case? I'm talking more personal preference than anything - even if you can make the calculation work, I just don't like to see toenails holding up a floor joist.

    And is it just me or is this narrow 2x2 ledger cracked? Another reason not to use a narrow ledger.

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    Last edited by Mike Truss Guy; 03-09-2009 at 09:19 AM.

  52. #52
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    I'm with the thumbs down crowd. This "ledger" shouldn't be nailed to the sill plate.

    A ledger should be on the header/girder too support the tails, notching the tall joists if necessary, otherwise the correct hangers. Although I think I see two (header) spanning the brick opening in the original bearing foundation wall, I don't see any evidence they have been fastened showing they're functioning as a unit, inside left of the opening looks like the sill plate is missing a chunk already. Don't see any thing to evidence over the rest of the existing foundation wall. The 1st of each on a single hanger see some screws, 2nd of each double joist just sistered up afterward bad some seem to be floating.

    Termites? don't see sheild, moisture? looks like one of those tails in the pics is wet.

    I'd like to see a pic from under the floor from the other side of the bearing/sheer wall from under the original side of the foundation.

    Where are the plans?


  53. #53
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Quote Originally Posted by H.G. Watson, Sr. View Post
    This "ledger" shouldn't be nailed to the sill plate.
    You might be right that it is nailed to the sill plate, see post #10, 7th photo down (next to last photo in that post) - looks like it is nailed to the sill plate.

    Jerry Peck
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  54. #54
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    Default Re: Attaching floor joists to existing foundation - is this acceptable?

    Yes this is what I was talking about, attached first thumbnail (ledger8.jpg) obviously this ledger is nailed into a 2x sill plate here, since same foundation wall seems this is the case throughout. Note header above.

    Note 2nd thumbnail (ledger3.jpg) two double headers side by side (four ply girder)? bearing only on this so-called ledger at opening in original foundation wall - should be bearing 4" not floating. From outside photos of foundation appears might be two doubles for load bearing walls (see roof lines of addition note alcove) that are supported on one of the two intermediate pillars and eventually bear on the outer foundation - one pair on the longer wall of the alcove. I suspect this opening in the original foundation wall is just under the original exterior door (see french doors).

    Don't see any evidence the header/girder on original foundation wall is nailed/built-up.

    Essentially looks to be tail joists assume bearing on outer new foundation wall's sill plate. Don't see any signs of scabing/strapping in the other photos.

    I'd be calling in an engineer to review plans and construction to protect my own interests before your "builder" goes a step further.

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    Last edited by H.G. Watson, Sr.; 03-09-2009 at 01:55 PM.

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