Replies

1. 
   Scott_Frankland | Feb 05, 2002 01:27am | #1

   *
   Pre-engineered floor joist.

   Scott

1. 
   Tn...Andy | Feb 05, 2002 03:41am | #2

   *The fifth multiple ( or divisor ) of 8 feet.4 x 24" = 96" ( 4 spaces, 24" on center joists)5 x 19.2" ( real close to 19 3/16) = 96" ( 5 spaces, 19.2 on center joists)6 x 16 = 96" ( 6 spaces, 16" oc)And as Scott said, the only place I've seen it used is on pre-engineered floor joists where 24"oc would just be a little too far apart to meet floor load specs......though I guess there is no reason you couldn't use it on regular joists, rafters, etc,

1. 
   Jeff_J._Buck | Feb 05, 2002 04:01am | #3

   *it's been on tapes way before pre-engineered stuff.....but still divide's 8' by 5. Just on old way of layout. Jeff

1. 
   Matthew_Steadman | Feb 05, 2002 04:25am | #4

   *I some times use it on low budget homes to save on tji costs.

1. 
   Phill_Giles | Feb 05, 2002 05:52am | #5

   *Used to see it on older homes with "real" rafters to handle a snow-load.

2. 
   ken_hill | Feb 05, 2002 08:05am | #6

   *So what does 'BCI' stand for?

3. 
   Phill_Giles | Feb 05, 2002 06:48pm | #7

   *In what context ? If you worked on the Cape, it stood for Broward County Transit; to many it stands for Biodiversity Care Trust; and to some it means Basic Career Training.

4. 
   ken_hill | Feb 05, 2002 10:49pm | #8

   *PHIL- I've always been determined to learn something new every day. With your post I guess I can take the next three days off! ...............Seriously, I've heard reference to the 19.2" incremental spacing as having something to do with 'B C I' ( that's Bee-See-Eye phonetically, Phil ).

5. 
   Dirk_Johnson | Feb 06, 2002 02:45am | #9

   *Great guys huh? Scott - never using pre engineered joists, is there a standard top cord dimension that works with this odbball number? Andy - if you were to layout joists on something less than 24" O.C. - doesnt that only complicate the decking and subsequent framing?

6. 
   Scott_Frankland | Feb 06, 2002 04:05am | #10

   *After the first job I did with them I swore I would never go back to 2x lumber again. I used them in a ICF demo home several years ago and it was the first time I even noticed those marks on the tape.Scott

7. 
   Phill_Giles | Feb 06, 2002 06:18am | #11

   *Ah, between the font and the single quote, that looked like BCT when I was tired, sorry. I've seen that acronym many times; know that it has something to do with continuous intervals; but I have no idea what the real base wording of the acronym is.

8. 
   piffin_ | Feb 06, 2002 08:28am | #12

   *It saves a buck on framing lumber but you can end up paying it back on spoecial order fibreglas insulation. It really only pays on larger commercial jobs!

9. 
   Richard_Utter | Feb 07, 2002 03:02am | #13

   *So the only reasonable time to use it would be on first floor joists that more often than not, do not get insulated.

10. 
    Phill_Giles | Feb 07, 2002 03:59am | #14

    *Well, you can also think about Icynene, when you use that stuff with "I" section engineered joists it creates a structure that's rock solid. Same with insulated panels (like EIFS).

11. 
    Tn...Andy | Feb 07, 2002 02:53pm | #15

    *"Andy - if you were to layout joists on something less than 24" O.C. - doesnt that only complicate the decking and subsequent framing? "Dirk,No, no really....16" OC , you break a sheet of 8' material at the 4' mark, and you're on a joist...With 19.2, you break on the second or third joist/truss/whatever and next run, you take the leftovers and break on a different one.The insulation factor is a valid one, though, since standard is only made for 16 and 24.The only time I've ever used the 19.2 spacing is on floor trusses that specified it. I personally would go to 16 if there was any doubt about 24 being strong enough.

12. 
    Tim_Mooney | Feb 07, 2002 03:29pm | #16

    *Is sprayed insulation out with you boys ? Seems to be getting common here.

13. 
    Matthew_Steadman | Feb 08, 2002 04:56am | #17

    *Sprayed insulation sounds great to me. I hate fiberglass. It's miserable to work with, around or, near. I start to cough as soon as it's in and don't stop until the sheet rock's up. The problem is I don't know anything about the blown on stuff. What dose it cost? Who dose it?

14. 
    Phill_Giles | Feb 08, 2002 05:43am | #18

    *read this one : http://www.icynene.com/

15. 
    David_Cass | Feb 08, 2002 10:53pm | #19

    *I worked on a roof w/ 19.2" once. I also worked (at another time) with a fello who called them cubits.Not exactly right, but close enough for a name.

16. 
    David_Thomas | Feb 09, 2002 02:13am | #20

    *Matthew: I pay $0.60/sq ft for the first inch (R-7) of urethane foam. $0.50 for each subsequent inch. The first inch includes the mob costs. Filling the bay with foam gives great R-value. Most cost effective is probably 2 inches and then put in the next smallest FG batting. Spray-on is great for reducing air infiltration. It also stiffens up the sheathing a bit. -David

17. 
    Mike_Maines_ | Feb 09, 2002 05:49am | #21

    *David, I seem to recall asking you this a long time ago, but I forget. Wouldn't two inches of foam against the sheathing and fiberglass inside of that put a vapor barrier in the wrong place? Like against the fiberglass?PS my cousing lived up there for a while working on the pipeline. Named his dog Keen Eye. Always thought that was pretty clever.

18. 
    Matthew_Steadman | Feb 09, 2002 11:23pm | #22

    *Thanks Phill and Dave.

19. 
    p_m | Feb 10, 2002 06:49am | #23

    *The reason for the diamonds is so you can measure things that are 19 3/16" apart without having to look at the numbers and little lines. -Peter

20. 
    Mr.T | Feb 13, 2002 04:44am | #24

    *I thought the diamonds were so every few months some one could post a question asking what they are for?:)T

21. 
    ken_hill | Feb 13, 2002 11:02pm | #25

    *Keep in mind the marks are NOT 19 3/16" multiples. They are EXACTLY eight feet divided by five or: 19.2" ! ....... :o) Ken

22. 
    Steve_Schefer | Feb 13, 2002 11:43pm | #26

    *Ken you are absolutely correct. You all may not believe this but it really happend just yesterday. Two years ago a good friend of mine and protector of others was attacked and beaten with a baseball bat. We thought we had lost him for sure but he pulled through suffering severe memory loss. He's getting better but still not quite ready for society yet. Yesterday I went over to see him and his dad. I asked him if he remember about 19 3/16 and he responded "not 19 3/16 it's 19.2 over 8. His dad who is the GC couldn't rember what it was for and his son said "Dad, it's rafters, you taught me!".

23. 
    Eric_Pinkston | Feb 14, 2002 04:09am | #27

    *The latest JLC said their starting to make pre-cut insulation for 9 foot walls. Hopefully the 19.2 wide stuff will be here soon too.Eric

24. 
    Phill_Giles | Feb 14, 2002 07:00am | #28

    *Oh they have it, they even have the over-sized stuff for the engineered studs and for metal; but hardly anyone keeps it in stock.