Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Dockside Chat
Reload this Page >

builder question, joist placements

Notices

builder question, joist placements

Old 06-25-2007, 09:26 AM
  #1  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default builder question, joist placements

Here is the drill,
2 x 10 PT joists on 16" centers. 48" from one edge is a triple thick beam. With the beam in place the next joist is within 2" of it and the brackets interfere. Because the span is now about 18" can I just leave it out? Or should I toe nail it in without a bracket? Do I continue the 16" placement from the center of the beam or from the running joist placement?

Next question, One edge of the floor joist structure is triple thick 2 X 10". The beam sits entirely upon a cement tie beam for its length. The edge butts up to the ledger. I cant use a Simpson triple or even double bracket because the outside edge will protrude past the edge of the house. I was thinking a single bracket against the ledger and sister the other two against the first then maybe a few extra twist straps along the length to secure her down to the tie beam. What do you suggest?

Thanks guys.

140 MPH Florida code
baitkiller is offline  
Old 06-25-2007, 10:31 AM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Mar 2002
Location: Milwaukee, WI
Posts: 502
Default RE: builder question, joist placements

Baitkiller

Hard to tell without something to look at. You could use a concealed hanger for the joist next to the triple beam (Simpson HUSC) or standard OSB is rated to span up 24" so the 18" span should be fine. I would continue your layout at 16" OC and discount the beam location, if you don't when you sheet the floor you will have to cut.

As for the triple to the outside. It's there to support the wall above evenly. Use a double hanger and sister the last joist to the double. Can't hurt to use a few extra straps.


Disclaimer - without seeing drawings or site conditions the above opinions are those of the author and should not be used without consulting with a local building professional.
buzzellc is offline  
Old 06-25-2007, 10:36 AM
  #3  
Senior MemberCaptains Club Member
 
Garett's Avatar
 
Join Date: Feb 2003
Posts: 24,235
Default Re: builder question, joist placements

Pictures, I for one could use some pictures, at least sketch drawings.

Is this new construction or existing? Will it be inspected?
Garett is offline  
Old 06-25-2007, 10:48 AM
  #4  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default Re: builder question, joist placements

Ill go take some photos, please check back in about 45 minutes.
baitkiller is offline  
Old 06-25-2007, 11:28 AM
  #5  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default RE: builder question, joist placements

Pics added!


Overview


Joist placement


Tie beam to ledger with triple beam placement


Double hanger, not over hang past edge of house.


Single hanger, can I use it?


See, its level
baitkiller is offline  
Old 06-25-2007, 11:44 AM
  #6  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default Re: builder question, joist placements

I'm thinking maybe I could cut off the overhanging bit of the double. My cut off wheel and angle grinder would do it in seconds.

BTW current count is 980 nails in by hand. Sore.....

Bye for now, gotta go make a dollar.
baitkiller is offline  
Old 06-25-2007, 12:05 PM
  #7  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Aug 2003
Location: On The Razors Edge
Posts: 10,131
Default Re: builder question, joist placements

Personally, since it's bearing on the tie-beam, you don't need a hanger.
Just1more is offline  
Old 06-25-2007, 01:24 PM
  #8  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 23,571
Default Re: builder question, joist placements

I suspect that end triple is just there to carry a wall above it. The midspan triple may be for the same reason? That end triple should probably flush with the end of the header/edge of wall? Horizontal strap with tapcon(s) to existing masonry? Or is that 1/2"-3/4" setback for structural sheathing? In any case, Florida code requires any changes to any structural issues be stamped by architect/engineer. Personally, I'd let that 18" span go..5/8" is span rated for 25"for flooring (25"/40" span on back of plywood?)
billinstuart is offline  
Old 06-25-2007, 05:08 PM
  #9  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default Re: builder question, joist placements

Bill thats right, the 1/2" setback is for the sheathing. Once sheathed every single stud is strapped and tap-conned into the tie beam. I left 2" on the outside walls to accomodate the rim joist and sheathing. I need to trim the ledger so I am not forced to relief cut the sheathing later. We will see how well my famous rubber ruler bears me out then.

The triple beam that is inset supports a column that in turn supports the second floor joists surrounding the stair well. The outside beam of course supports the two story flat wall on top of it. That's a big wind load to account for and I should have done it in block. Unfortunately the engineering firm I hired sucks big fat green donkey *&^%.

baitkiller is offline  
Old 06-25-2007, 08:06 PM
  #10  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 23,571
Default Re: builder question, joist placements

Since the joist(s) are over the concrete beam, the simple solution would be use the single joist hanger, then nail the other -2- joists to it. Frankly, with the structural sidewall sheathing and probable 3/4" t&g floorply (or even 5/8"), that joist hanger isn't loaded much.
billinstuart is offline  
Old 06-25-2007, 10:51 PM
  #11  
Senior MemberCaptains Club Member
 
Garett's Avatar
 
Join Date: Feb 2003
Posts: 24,235
Default Re: builder question, joist placements

A triple 2x10 beam on a tie wall, why? Is this code because of the hurricanes you guys get? So do all load bearing and partition walls have to have triple beams as to provide a rigid nailing surface? Then I’d have to assume tie down straps are need every few feet apart to hold down the toe plates? Because of the weather Florida gets is that why you have to have 35-40 nails per joist hanger?
Garett is offline  
Old 06-25-2007, 11:07 PM
  #12  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Mar 2005
Location: Whitesboro, texas
Posts: 8,050
Default Re: builder question, joist placements

No treated lumber or moisture barrier on concrete ?

welder is offline  
Old 06-26-2007, 06:33 AM
  #13  
Senior MemberCaptains Club Member
Thread Starter
 
Join Date: Sep 2005
Location: s.w. florida
Posts: 4,172
Default Re: builder question, joist placements

The lumber is PT, a barrier will go under it as well. 40 nails per hanger makes for a happy inspector.
baitkiller is offline  
Old 06-26-2007, 08:28 AM
  #14  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 23,571
Default Re: builder question, joist placements

Every stud will be strapped to the tie beam. Each nail is good for about 100#'s of uplift, so if you have a calculated uplift of 2000#'s, each end of the strap shoud have about 20 nails, or 40 nails total. 10d hot dipped stubbys or common..the shank diameter will be spec'd. The plywood floor/wall/roof sheathing also forms a "shear diaphragm" to counteract diagonal loads. Even the sheetrock becomes a part of this structure, and must be applied in a prescribed method.
billinstuart is offline  
Old 06-26-2007, 10:03 AM
  #15  
Senior MemberCaptains Club Member
 
Garett's Avatar
 
Join Date: Feb 2003
Posts: 24,235
Default Re: builder question, joist placements

Thanks Bill .........it goes to show me how little I really know when it comes to building codes in other regions. Timber, straps, nails and labor.....man all those extras sure would add to the cost of a project.


One thing I'm rather surprised about though is why code would allow the use of common nails if all of those steps must be taken or regulations must be abided by? IMHO ardox nails as we call them up here (twisted or spiral nails) have a much greater holding power then any common nail will every have ~ actually up here other than finishing and roofing nails common nails are Very scarce.
Garett is offline  
Old 06-26-2007, 11:45 AM
  #16  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 23,571
Default Re: builder question, joist placements

It's all about shear..the side load. It gets more complicated..ACQ treated lumber is very corrosive and requires that straps/fasteners be able to resist the corrosive chemicals. Same with proximity to salt air environment. The new MCQ treated material is much less corrosive, btw.
billinstuart is offline  
Old 06-26-2007, 04:46 PM
  #17  
Senior MemberCaptains Club Member
 
Garett's Avatar
 
Join Date: Feb 2003
Posts: 24,235
Default Re: builder question, joist placements


Garett is offline  
Old 06-26-2007, 05:01 PM
  #18  
Senior MemberCaptains Club MemberPLEDGERPLEDGER
 
Join Date: Apr 2006
Location: Struggleville
Posts: 7,536
Default Re: builder question, joist placements

I would have just backfilled the concrete blocks, threw down a plate and poured it.
Bugbuster is offline  
Old 06-26-2007, 06:12 PM
  #19  
Senior MemberCaptains Club Member
 
Join Date: Nov 2004
Location: Key West
Posts: 2,385
Default Re: builder question, joist placements

The 2" difference on the centers makes little structural difference, the only problem with that could be breaks for decking. You have to keep that in mind, lest your plywood falls 2" short. As far as that triple beam, I see no reason why you couldn't simply use an gusset angle bracket and lag in.

CayoHueso is offline  
Old 06-27-2007, 08:52 AM
  #20  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 23,571
Default Re: builder question, joist placements

Bug..like in pour a cell with mortar and stick a bolt in it? No can do. That's a continuous tie beam with steel. Lotsa steel. Tied to the footer with steel. Lotsa steel. You guys in 'Lanta got it easy. Now if you can just sell the existing inventory.............
billinstuart is offline  

Thread Tools
Search this Thread