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Discussion Starter · #1 ·
Hi everyone, I am new to this forum but hoping to get some help with an issue I am facing building my first deck:

I ran into a height issue with how tall I poured my footers. I needed to lose about 2.5″ in height between the frame and the decking, and I discovered that you can notch your joists and beams if following strict guidelines.
Now just a few facts on the build:
-I am currently located in Colorado and my city uses the 2015 IRC
-The deck is a 16’x20′ attached to a ledger on the house
-My footers are 12″, attached to which are 6″x6″ posts, which I have notched to attach my beams which are 2-2″x10″
-I am using pressure treated southern pine, with a beam span of about 6’10” and a joist span of about 8’2″
What I want to do is notch my beam where it crosses my post with a 1.5″ notch. This will need to be an actual width of 5.25″ and this is where the code loses me. I see in IRC 502.8.1 that you can notch the edge of a board to 1/4 its width (which I should be in the clear on) but I don’t see how wide this notch can be. The illustrations provided show a single beam span, but I am using 2 lengths of beam to make up the 20′ run.
I am fairly certain I will be good on my joist notching as this seems to be fairly common and the notch wont be more then 3″ wide.
Any ideas on whether this beam notching will be permissible?

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retired framer
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Basics first, is the 20 ft long and the posts are,? ft from each ends with any posts? between them?
The beam will be how far from the ledger?
What is the notch for?
Will the deck joists cantilever passed the beam?
Yes you will find a notch in the book, that does not mean that it will actually pass inspection. If you are close to span limit, a notch might take it over the limit.
 

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Discussion Starter · #3 ·
Basics first, is the 20 ft long and the posts are,? ft from each ends with any posts? between them?
The beam will be how far from the ledger?
What is the notch for?
Will the deck joists cantilever passed the beam?
Yes you will find a notch in the book, that does not mean that it will actually pass inspection. If you are close to span limit, a notch might take it over the limit.
I have 2 - 20 foot long beams, my center beam has 6 posts and my outer beam has 4 posts, the greatest beam span between these posts is 8'2". I have a 3 inch cantilever on one side of my middle beam and an 11" cantilever on one side of my outer beam.

The beam to ledger distance will be 7'8" and the span between the two beams is 8'2". I was planning to have my deck joists cantilever 6" past the outer beam.
 

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retired framer
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I have 2 - 20 foot long beams, my center beam has 6 posts and my outer beam has 4 posts, the greatest beam span between these posts is 8'2". I have a 3 inch cantilever on one side of my middle beam and an 11" cantilever on one side of my outer beam.

The beam to ledger distance will be 7'8" and the span between the two beams is 8'2". I was planning to have my deck joists cantilever 6" past the outer beam.
So what is the reason for the notch? and which beam do you want to notch?
Are the joists to be 2x8 or 2x10?
 

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Discussion Starter · #5 ·
So what is the reason for the notch? and which beam do you want to notch?
Are the joists to be 2x8 or 2x10?
My intention with the notch is to reduce the height of the deck floor. Based on my footer height, I can't reduce the post size, but I only need about 2.5 inches in height reduction to align the deck floor to my living room door.

Both joists and beams are 2x10, with the beams being made up of 2 - 2x10s. I would like to notch both beams 1.5 inches and my joists 1 inch.
 

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retired framer
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My intention with the notch is to reduce the height of the deck floor. Based on my footer height, I can't reduce the post size, but I only need about 2.5 inches in height reduction to align the deck floor to my living room door.

Both joists and beams are 2x10, with the beams being made up of 2 - 2x10s. I would like to notch both beams 1.5 inches and my joists 1 inch.
Your deck should be well below the floor inside so, I agree that decks and beams should all be 2x10 but in this situation I would be getting advice on span tables.
Changing the beams to 3 ply 2x8s would give you a full 2" and changing the joists to 2x8 would gain you another 2".
There are people here that have one hand on a span table , some one might be along to help out.
 

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Discussion Starter · #9 ·
I missed something. You have 6x6 posts ... why can't you cut the tops of the posts down a little?
The posts are already about 5 inches in height. If I were to further cut them by 3 inches I would have the entire weight of the deck resting on 2 inches of post which seems like a risky move given that could cause the post wood to crack and fall apart. My goal is to maintain the structural integrity of the post by notching the beam.
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The posts are already about 5 inches in height. If I were to further cut them by 3 inches I would have the entire weight of the deck resting on 2 inches of post which seems like a risky move given that could cause the post wood to crack and fall apart. My goal is to maintain the structural integrity of the post by notching the beam. View attachment 700553
If that is all the problem is a 5 1/2 in 2x6 block laying flat would be fine.
 
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The posts are already about 5 inches in height. If I were to further cut them by 3 inches I would have the entire weight of the deck resting on 2 inches of post which seems like a risky move given that could cause the post wood to crack and fall apart. My goal is to maintain the structural integrity of the post by notching the beam.
I'm dense ... I don;t understand what your situation is, I cannot follow the description of the structure. Are you reversing the term beam and post? How is your post only 5" high? Is the deck almost on the ground?
 

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I'm dense ... I don;t understand what your situation is, I cannot follow the description of the structure. Are you reversing the term beam and post? How is your post only 5" high? Is the deck almost on the ground?
I don't know where the ground is, the piers are to close to the beam. Or to low for the beam to just sit on the piers.
 

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The complication is caused by the OP wanting the exterior deck level with his Living Room door....

My intention with the notch is to reduce the height of the deck floor. Based on my footer height, I can't reduce the post size, but I only need about 2.5 inches in height reduction to align the deck floor to my living room door.

That should not be. A deck requires step-down if for no other reason than climate...
weather, ground movement, and material expansion and contraction.

He's unknowingly looking for future aggravation.
 
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