double deck porch advice

[farmerpsv]

Hey friends,
i've gotta say that tractorbynet is the greatest site on the web. there is more knowledge here than most college campi ( which may not be saying much /forums/images/graemlins/shocked.gif). anyway y'all are a great bunch, always get help and enjoy reading all the posts. now, to the current project...
am building a house and want to attach a double deck wrap around porch but don't know the size lumber to use. the house is a double A victorian (two side by side 14' sections offset two feet). the porch will stand 8' from one section and 10' from the other. the side portion will stand out 8'. the total front portions will be 36' wide and the side portion will extend about 14'. i want to be able to have the hot tub on the top porch, in the corner, so i imagine this thing will need girth. my questions would be:
1. what size ledgers to use?
2. what size joists?.
3. 6x6 posts adequate? spacing?
4. buried posts or concrete footing? (distance to upper deck is 14'from ground)
5. what to do with the corner when i run out of ledger, will a doulble joist resting on a post suffice to run floor joists off of?
and any other advice you may have for a died in the wool do it yourselfer.
thanks,
paul

 

[bczoom]

Paul,

Check out my posts in this thread

Are the pics I posted similar to what you're considering?

Brian

 

[PBinWA]

Check out this site

The Journal of Light Construction

http://www.jlconline.com

They have articles from back issues that give a lot of good advice and have done a fair amount of coverage on deck building in the last two years.

 

[EddieWalker]

As much as I hate doing it, in your case, I think you should pay for an engineer to design it for you. The span you mention and the unknown weight of the hot tub plus the type of soil you have add up to some variables that nobody should be guessing on.

For example. What is your frostline, or how deep do your footings need to be? What size hot tub will you put in? 1,000 gallons will be 7,000 pounds. That's a HUGE issue, especially when your tying it into an existing structure AND putting it on the second level.

I would also be extremely hesitent on listening to anybody's advice on how to do it who doesn't have the qualifications and is willing to put it in writing.

Once you know for sure what it will take, then it should be a fairly simple project that you will enjoy doing.

Eddie

 

[beenthere]

Putting a 'ledger' on a house is
1) critical from a structural standpoint, as normal house construction isn't engineered for the forces of a deck.

2) critical from allowing water to penetrate the walls, and behind the ledger, promoting decay problems that haunt one later on.

Free standing would be my choice, as much as possible.

A construction certified engineer would be my suggestion as well.

 

[dmccarty]

Paul,

Check out the Journal of Light Construction website that was listed previously. There have been articles in the last year or so about attaching ledger boards to the house. What I took away from some of the articles and letters is that the ledger is often attached incorrectly to the house. The ledger failing under load is often the cause of the deck failures you see in the news.

Using the right kinda of fastener and spaced correctly is critical for the ledger.

The size of your ledger, size of joists, their spacing, post size, post height, and post spacing depends on the load on the structure.

After reading the JLC articles I would get a PE to come up with a design and then you can build it. A few dollars for the design is cheap compared to what you are building.

There have been deck failures in my area of the last year of so where people have gotten hurt. Chicago had a deck failure that injured dozens of people and killed quite a few.

Will you need a permit to build the porch/deck? If so you might have to get an engineer anyway.

Later,
Dan

 

[farmerpsv]

thanks everyone for the input and links. sounds like an engineer might be in order. was figuring on z flashing the ledger and attaching with 2 lag bolts every 24". still, would be worth the cost of being safe. 7000lb is alot of weight, and that's without wet bodies /forums/images/graemlins/smile.gif
thanks again
paul

 

[beenthere]

Call the wood dept at VPI in Blacksburg.

Brooks Forest Products Center
(540) 231-7134

They will have some wood engineers who should be able to give you some good pointers, I would think.

 

[gates]

Are you going to get a permit? If so , draw the plan the way you are considering building it and submit the plans for review. The plans reviewer should make necessary changes, required by code, with in reason. They will not design the project. If no permit I definetely agree with others, hire a structural engineer! Information obtained on this forum may be area dependent, this is something else to consider. Building code is not universal, ie. depth of footers.

 

[dmccarty]

</font><font color="blue" class="small">( ... attaching with 2 lag bolts every 24". )</font>

I am pretty sure that using lag bolts was a no no on the ledger board. JLC's article was pretty in depth on this subject. I think the recommendation, depends on load of course, was BOLTS and washers, not lag bolts, every six inches or some very close distance.

You should be able to access the JLC articles without being a member. You will see a summary of the article. If you are doing any sort of construction, barns, decks, plumbing, tiling, etc around the house I highly recommend the magazine and the website. If you pay for access to the website they have their magazine articles going back for years. They have a mechanism to keep a library of their articles on the website. JLConline is a great reference.

Later,
Dan