Hi DIY team!

I'm venturing to build a deck with the following characteristics:

-427 SQFT
-24 inches from floor
-Attached to house
-Trex Composite Decking with PT framing members
-2x10 for Joists, 2x12s for Beams, 6x6 for Posts.

Please see the attached pics:

1-The post to beam connection layout
2-The post locations
3-The joist layout [I'm using flushed beams, not dropped on top of beams]
4-3D View

I'm using Lowes' deck designer application and it seems it only spits out dropped beams. My problem is that since I only have 24 inches of height my posts would short, I won't have much air flow/clearance, and if I frame with 2x8s I feel I won't have the support I need for a Pergola. I feel that with 2x10 for joists and 2x12 for beams I'm building a sturdier deck.

My questions:

1-You'll see in the post location page that I'm not evenly separating the beams vertically (i.e. first section is 9'4'', second and 3rd are 7'6''. The reason why is because if I push back the first beam towards the house I'll get only 3 posts and I need more support in the middle section where a Pergola will be built. Is this uneven separation possible? any red flags? Since I'm using 2x10s for joists I should be ok since the max span is 12' I believe. I'm also using blocking for the 9'4'' section to reinforce the area.

2-What's the minimum distance to have between a footing and the house/foundation? I'm using 1 foot of separation to be able to dig the hole and avoid any issues with the house.

3-You'll see in the post location page that the horizontal post separation is not the same as well (5'1'', 5'11', 5,11') as I need more weight support on the right. is this OK since I'm staying within the maximum span for 2x12s?

4-Do you recommend blocking for the rest of the 7'6'' sections on the joist layout page?

5-Any general corrections/suggestions?

Thanks!

 

Composite Decking: Excellent, you will never be sorry you made that decision.

You need to check with your local building dept for anything specific to your area.

2x10 for Joist: Good
2x12s for Beams: Good
6x6 for Posts: Overkill 4x6 is sufficient

Add a 4th beam where the blocking is, 3 posts are sufficient

Not sure where the notched post is at but notch posts are a weak point where it can split

Need to consider railing installation, there was a recent thread about mounting, need to consider that now, not later

A much wider set of steps will look a lot better

 

Just some light reading regarding deck construction that could answer most of your questions. It is good that you have the plan so thought out. Notched posts are not likely to "split", but the beam must be bolted to the tang to make the beam and post one unit.

http://www.awc.org/pdf/codes-standar...Guide-1405.pdf

 

I've seen several examples of "notched" posts where the cut + side loads provide the perfect point to split.

Notching posts is just not desirable, they can be avoided with some planning.

 

Just an observation...seems to me like you could get away with only two beams, which would cut the amount of holes/footings/posts in half (six total). Just run them the other way (along the length)..

 

And if you did a cantilever, you could do your beams like such, which gives you the added post height without notching:

 

Beams as illustrated above are not allowed in most places where there are codes and decks are inspected. In those places, notching is required. See the dca6 that Chandler linked to... all your questions are pretty much answered in there.

 

I just looked up the joist span for a 2x10 southern pine board spaced 12" O.C., and it is 16'-2". You could move the top-most beam down a few feet and omit the center beam altogether.

 

Okay. I wasn't aware of that. My brother in law just built a deck that way in VA, but he didn't get it inspected.

 

Hey Chandler, do you have a link for specifications/requirements for a covered/screened-in porch? I'll be building a deck this year with plans on enclosing it next year.

 

Too late to talk you into a free-standing deck? I hate punching holes which are doing their job and keeping the weather outside.

 

Plans submitted for permits will be modified to show allowed spacing between support piers and beams. It would also be prudent to have your plans for a covered patio presented at the same time so that sufficient structure is build into the deck to support your building on top of it.

 

See that is not true, that is how I have built every deck avoiding notching posts and after 30 years the decks are still standing.

And every deck was inspected, I do not cut corners when safety is involved!

 

Yeah, see, that was 30 years ago. What matters is what the codes are today... not what was allowed 30 yrs ago. I built them that way too. We also used to use 4x4 posts and there was no such thing as a lateral load device. All depends on the local code, which is exactly what I said.