Constructing a beam from 2x10 's

[Michael Daly]

"if serviceability is the governing criteria." I type fast - sue me.

Mike

[Michael Daly]

You can get drugs to treat your obsessive behavior.

Mike

[Ed & Sue Beresnikow]

J. Clarke wrote: ...snip

Damn! there is going to be a lot of pissed housing contractors around here if they have to stop using doubled 2x12 lintels in the 3ft wide doorways and windows under 6-8ft wide ... way oversized! - especially on the non-bearing walls! Hey, Joe! saw me up a 1/2doz of 5"inch cripples will ya? :-)

Ed

[Buell Boy]

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

[Buell Boy]

I've tried OVER and OVER to reach the local building departments. Their website is not useful, and reaching a person by phone is a 2-3 week proposition. Since the Hurricanes here (I'm in Florida in an area where 3 hit last year), there is so much building going on that it's almost impossible to speak to anyone in the building or code departments. Permits in our town are 6-12 months from the time of application.

Good suggestion though I just WISH I had a building inspector avaiable. I also talked to a clerk about the project. She said they are so backed up that projects like mine are not being permitted at this time- she basically said "have at it"..

Welcome to Florida!

IRC correctly the =BC" steel flitch plate w/bolts may have been an alternative to either =BD" or 3/4" ply nailed.

BX1's best bet is to check with Building/Zoning or Community Development in his town and see what they say. To overbuild is never a crime

[Ed & Sue Beresnikow]

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