Deck Beam Sizing And Post Spacing?

diyerforever

I am sparky by trade asking a little help about the deck I would like to build. Let me explain the deck first. The overall deck will be 29'6" x 12' and 8'H at the highest point. The 29'6 is due to yard restriction. But anyway if you start at one end there will be 3'6" then a 12'4" driveway then 13'8" to the end. I can place the posts for the beam anywhere except in the driveway.(obviously) I was planning on attaching the deck to the house and having a beam size of 3- 2x12 combined with 3-6x6posts 14' on center and 2x10 joist. I am asking is this code (and safe). The drive slopes down so beam height is not a problem.

I thought about turning the beams to run away from the house and span the driveway with the joist but that is a lot of posts. If this is the only way that it can be done than thats what I'll do.

I heard of placing a flat piece of 1/4 or 3/8 steel between the beam and bolting it all together to take out the bounce and strengthen the beam.

I was hoping someone on this site has run across this before or has any advice on the situation. I am open to any and all suggestions.

Thanks in advance,
sparky by trade diyer forever

RobertCDF

I have spanned large driveways before with a 14" glulam beam. You MIGHT be able to use 3 2x12's depending upon the loading requirements of your local building department. IF NOT you could most likly use (2) 11 7/8" microlam for your beams. (I have used these to span 18' with a 40 PSF LL and 15 PSF DL) Check with your local building department for permits and to double check your plans.

__________________
Robert Shaw
Colorado Springs Custom Decks
Colorado Custom Decks
Custom Composite Decks

bob the builder

Where I live if you want post spacing every 14' you would need 4/2x12's not 2. Then 2x10's 16" o.c. for s. pine # 2.

You could run your beam into the house if you have a way to attach it you would still only need 3 posts total. The benefit I guess would be no seams on deck boards that are 12' long...

Yes you could use a fletch beam/steel sandwich but it's not needed.
Bob

onhitch

yes , run your beams pependicular to the house and you are golden!

diyerforever

What about 14" beams? Wonder how long it would take to get those? Are they readily available? How much are they?(roughly) Would I need to rap them with anything?

Thanks for the replies,

diyerforever

RobertCDF

When I used the 14" glulam I think it ran me $8.XX a linear foot I would have to look that up to be sure. But it is 3" wide so you only need one instead of 2. I did cover it with flashing to keep water from sitting on it. But there are pressure treated glulams out there. I saw an ad for them in Professional Deck Builder magazine.

__________________
Robert Shaw
Colorado Springs Custom Decks
Colorado Custom Decks
Custom Composite Decks