# Deck Beam Question



## pfloyd (Feb 28, 2008)

So , I am pricing out a 19' x 19' deck which will be built underneath a 17' high upper deck. The new deck will be at 8 feet high and I will hang it off the 6x6 posts of the upper deck and probably add supplemental posts as well. The upper deck was framed with 2x12 and no beams , just joists straight across. The best i can gather is that is not to code, that 2x12's can only span a max of 16.5 feet at 12" centers.

I want to do the new deck properly with beams and joists hung flush (need headroom). I want to use LVL's but they are not rated for outdoor use. What are the alternatives for beams? It will be a sealed deck and it is underneath a higher deck, so its only moisture exposure will be from the air. The HO intends to eventually close it all in so it will be a garage, then storage above (the new deck),then the upper deck. Is it a big deal in this scenario to just go with the LVL's?

I built many decks last year at UBC (the university, not the code), and they all used LVL's but they had soffits put in.

there is a picture of it at the end of this album.http://picasaweb.google.com/guntfin/MyPictures


----------



## Jason Whipple (Dec 22, 2007)

If it were me, I wouldn't add any more weight to the existing deck footings. Build the new one on it's own legs. You don't know if the footings for the upper deck could handle the additional weight. If later on you find that to be true, you just bought two decks.

I don't see the need for LVL's either, Double TYP 2 x 12's work just as well with the right amount of spacing between footings and posts. Unless there's some reason you have to span that distance without support posts, use p/t lumber. 

Just my opinion.


----------



## pfloyd (Feb 28, 2008)

Jason W said:


> If it were me, I wouldn't add any more weight to the existing deck footings. Build the new one on it's own legs. You don't know if the footings for the upper deck could handle the additional weight. If later on you find that to be true, you just bought two decks.
> 
> I don't see the need for LVL's either, Double TYP 2 x 12's work just as well with the right amount of spacing between footings and posts. Unless there's some reason you have to span that distance without support posts, use p/t lumber.
> 
> Just my opinion.


 Its a garage at the bottom. I would rather span over it than post down to the slab. I dont know how thick it is. I want to keep it 2x10 because headroom it at a premium. The posts are seated on concrete garage pony walls, pretty thick and i assume they have proper footings on under the slab. Check out my Picasa picture album.I put a picture of it in there.

The rear of the deck will be pinned into the foundation walls, so only a portion of the deck will add load to the current posts. Adding this deck will actually_ help_ the upper structure i think, as it was poorly framed and has no bracing. Im thinking LVL's are worth the extra cost in this case. If I have two and joist off them the span is not a big deal anymore. Not too sure that 2 2x12's have the same rating as an LVL.


----------



## Patrick (Apr 12, 2006)

How do you find these homeowners with screwy houses, that want even screwier home improvements? You gotta find some normal work to do


----------



## rbsremodeling (Nov 12, 2007)

pfloyd said:


> So , I am pricing out a 19' x 19' deck which will be built underneath a 17' high upper deck. The new deck will be at 8 feet high and I will hang it off the 6x6 posts of the upper deck and probably add supplemental posts as well. The upper deck was framed with 2x12 and no beams , just joists straight across. The best i can gather is that is not to code, that 2x12's can only span a max of 16.5 feet at 12" centers.
> 
> I want to do the new deck properly with beams and joists hung flush (need headroom). I want to use LVL's but they are not rated for outdoor use. What are the alternatives for beams? It will be a sealed deck and it is underneath a higher deck, so its only moisture exposure will be from the air. The HO intends to eventually close it all in so it will be a garage, then storage above (the new deck),then the upper deck. Is it a big deal in this scenario to just go with the LVL's?
> 
> I built many decks last year at UBC (the university, not the code), and they all used LVL's but they had soffits put in.



What do the plans say??


----------



## Jason Whipple (Dec 22, 2007)

rbsremodeling said:


> What do the plans say??


Exactly, the 20k seems to be reasonable to me. Included would be 2-4k just to get "the stamp".


----------



## pfloyd (Feb 28, 2008)

Then the job wont happen. They wont pay that. And i dont work.I could probably pull it off fine, but man, this stuff is a lot of fine lines that need crossing.


----------



## pfloyd (Feb 28, 2008)

Patrick said:


> How do you find these homeowners with screwy houses, that want even screwier home improvements? You gotta find some normal work to do


 If youre a "craigslist whore" you should be in the same boat. Actually, this one is a referral.But yes, a "normal" job would be a nice change. Starting at the bottom, I guess....


----------



## RobertCDF (Aug 18, 2005)

You can get cedar glulams, and PT glulams. If the deck was on normal piers I would say no to the haging of the beam in between but since its on a footer wall I would feel fairly comfortable but would still like to see the footer at the bottom of the stem wall. Keep in mind that the new deck will add a loading of about 5,000 lbs to each of the 2 6x6 posts. Looking at the simpson book real quick I did not see a hanger that would fit on a 6x6 post and carry that kind of weight. You are going to need a 5 1/8" wide glulam to span your load the height of it will need to be determined by an engineer. (you could use a 3 1/8" gluelam but you would lose lots of headroom.)

I have used LVL's a number of times but they were propery flashed but now the building department wont let us use them anymore. The morons who dont know how to flash properly ruined it for the rest of us.


----------



## Dan_Watson (Mar 1, 2008)

In regards to the origional 17' high deck, where do the 2x12 joists run to if there is no beam?


----------



## pfloyd (Feb 28, 2008)

RobertCDF said:


> You can get cedar glulams, and PT glulams. If the deck was on normal piers I would say no to the haging of the beam in between but since its on a footer wall I would feel fairly comfortable but would still like to see the footer at the bottom of the stem wall. Keep in mind that the new deck will add a loading of about 5,000 lbs to each of the 2 6x6 posts. Looking at the simpson book real quick I did not see a hanger that would fit on a 6x6 post and carry that kind of weight. You are going to need a 5 1/8" wide glulam to span your load the height of it will need to be determined by an engineer. (you could use a 3 1/8" gluelam but you would lose lots of headroom.)
> 
> I have used LVL's a number of times but they were propery flashed but now the building department wont let us use them anymore. The morons who dont know how to flash properly ruined it for the rest of us.


 I dont really see many glulams anymore.They were everywhere in the 90's but they seem to be phased out unless they are huge structural projects.They are very heavy and would be overkill for a 400 sq ft deck. Microlams (LVL's) and "Timberstrands" are in heavy use in this neck of the woods.

This deck will be over a garage that will be walled in within the next five years, so I could build it as an interior space (there _is _a full deck above, after all)

As far as posts, there are 8, not 2, plus the back end will be anchored into concrete. Check the picture up top. I think 2 lateral microlams (lvls) will be fine if they are nailed directly to the 4 posts with added support posts underneath the LVL's anchorbolted to the concrete pony walls. Maybe I will double them.i know they are very strong , but they do tend to deflect and "bounce".Thats beyond strong enough, unless the concrete is crap.
I put in a bid for 7500, we'll see what happens. Thats materials/expenses for max 2500, and it gives me a 5000 dollar week.I think the issues i raised to them about the upper deck has them hedging a bit. I may have to kick rocks.......

Update..they passed.They want an engineering report on the whole existing deck first, as I suggested. Oh well. Sometimes honesty doesnt pay. I may have to go back to working for someone else for a bit.That _really _sucks. This is a tough thing to break into when you are starting out! I certainly dont think I overbid it!


----------

