Buell Boy wrote:
Sorry everyone. I don't take offense by your replies. My post was
severely lacking in details. I'll try to give them here.
The 2x8 beams are for a deck, about 30" above the elevation.
I don't think there is much risk to life and limb, but beyond that, I'm
over-engineering the design. The footer spacings are 6', the table said
I can use 8'. The joist spacings are 16", the max was 24". The max
joist span is 6', I'm using 2x8 PT (I could use 2x6 PT according to the
table).
All of the wood is PT for obvious reasons (an outdoor deck). I'm being
VERY conservative on materials and design.
The source that told me to use carraige bolts was the Stanley book,
"Building Decks" from Home Depot. That's the same source that said to
seperate the beams with PT plywood spacers. It's NOT an old reference-
it's Copyright 2002. Making a BEAM is on page 44, where they describe
the plywood spacers and the carriage bolts.
Given all of that complexity, I'm considering maybe just "sandwiching"
the 4x4 post with the 2 beams. It looks simpler is perhaps even
stronger.
Anyhow- my original question was "Do I really need the plywood spacers"
if I choose to build 4x8x20' beams from 2x8's? Should I just sandwhich
and forget bamking beams?
- BX1
I am glad to see you were able to hang in and reclaim control of your
thread.
I am far from familiar with Florida state regulations and suggest it be
worth a browse on the state web or look in a local library to ensure
conformance to the state requirements at least. Your municipality won't
necessarily apply the same rules but unlikely to be far off but I would
keep pressing them to at least acknowledge conformance so you don't end
up with a liability issue at some later date.
I think most of the group gave the indication that using parameters
above minimum code requirements is not going to get you into trouble for
this application.
The spacer issue might be a code requirement for built-up beams in your
rather moist environment and likely intended to prevent (or at least
minimize) potential for rot. When shim spacered I would be inclined to
use carriage bolts through the shims to ensure the integrity of the beam.
You don't specify that you plan to lay the joists across the top of the
support beam or hang them on hangers on the beam. This will influence
your "sandwich" vs "built-up" choice considering a potential for
deflection on the hang joists on a sandwich beam. And in this over top
model you don't indicate the amount of cantilever beyond the beam. Our
local reg's indicate a maximum of 24" but in context of the supported
span to a max 1/4 or 1/3 ... can't recall.
From a Canuck view, you seem to have a reasonably sturdy plan that will
serve your needs and should meet codes with the provision that you need
to be sure about required insect and moisture protection.
I did a quick DAG on Florida building codes and found some useful hits
to look through.
Good luck
Ed
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