# Opinion on Deck Frame using PT 4X6 Beam & 2X6 Joist



## Knucklez (Oct 21, 2007)

are you designing for absolutely astronomical dead load capability?

that's a lot of digging you need to do. lots of metal brackets to connect post to beam and post to pier. these things are expensive. i'm sure you can redesign to get better cost optimization. 

can you make it with 3 rows of piers rather than 4? that's huge savings. and in the same row a pier every 8' rather than 3?

for example, to dig a hole is virtually the same cost. rent the one man auger, put the 12" blade on it. cost & effort the same. drop in the 10" sonotube and fill with concrete. yes larger tube is more concrete, but concrete is $4/bag and you need like 1.5 more bags for this size tube (in my area we are 4' deep). so its not actually a huge adder. but now you can support much bigger load. you can span farther distance with two 2x10 or 2x12's. so think about it...


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## ricksample12 (Feb 6, 2015)

I'm going to be building a deck hopefully sometime soon also free standing. If it were me I would do 3 rows instead of 4. Then also reduce some of the piers per row. My current deck is 16' wide and they only have 3 piers spaced 5-6' apart. It looks like you have 24 piers... that could easily be reduced to 12-15 unless you plan on holding something very heavy on this deck like a semi LOL


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## Knucklez (Oct 21, 2007)

i just finished fully floating. well, i finished the foundation & framing. it gets tricky if you have such a deck along side of a house. other thing to keep in mind for floating deck is to make extra effort to stabalize because you don't get luxury of attachment to house. stairs can help, but strapping *and *blocking go a LONG WAY too.


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## 8cuda (Mar 31, 2015)

Thanks for the feedback. I will look at redesigning the layout of the piers. Since the deck will be free floating, I wanted the make the frame structure stable. I was going to use 8' joist, but I'm fearing that 2X6 8ft may deflect. 
Is HD pressure treated boards okay to use?
Randy


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## ront02769 (Nov 28, 2008)

We're it mine, I would look at two by eight or two bye ten everything, cut the number of piers, two rows of them only. Google "span tables southern yellow pine" and check out the jpist and beam tables to give you an idea of what different sizes will let you do. You may end up with a sturdier deck at the same or lower cost. And yes, PT wood is best for framing the deck 
Rovidence that you use the proper brackets and fasteners, e.g. HOT galvanized. Ron


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## fortunerestore (Mar 6, 2014)

One thing to keep in mind, before making freestanding deskis that how much weight your structure has to hold.The weather also defines the footing for the freestanding desk, like in colder climates you may need to get frost footings and in warmer climates it is recommended they be engineered.


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## GBrackins (Apr 26, 2012)

cuda,

check out the "Residential Wood Deck Construction Guide" as published by the American Wood Council. http://www.awc.org/publications/dca/dca6/dca6-12.pdf

This will provide you with beam and joist sizing based upon the species and grade of lumber used, and how to frame a typical code compliant deck.

Good luck!


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## ront02769 (Nov 28, 2008)

Good advice BUT while that will give you all of the spans, etc. it won't deal with the differences in local requirements around footings, deck blocks, etc. as that is different all around. Ron


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## GBrackins (Apr 26, 2012)

true about local differences, guess that is why it is called a Guide. We're lucky here in Mass that the BBRS adopted the Guide based on the 2009 IRC as a part of out State Building Code for residential construction as I'm sure you're aware.

Best advice is to verify local requirements with the building department.

It does provide footing sizing (based on 1500 pdf soil bearing capacity) in Table 4 and Figure 12 provides footing options. Of course nothing is better than an actual soil evaluation report, but seldom does a designer have this for a residential project.

The 2012/2015 IRC codes have adopted much of the guide directly into the code.


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## AndyGump (Sep 26, 2010)

> The 2012/2015 IRC codes have adopted much of the guide directly into the code.



I wish they would, especially the guard details. The IRC has nothing in there like that, not that I can find anyway.

All rails in California on a deck that is 30" high or above basically need to be engineered unless you are using a system that has been approved by ESR and is current in that approval.

Also, I have had luck in convincing a couple of Building Departments in my area of Calif. that the lateral device shown in the CRC is an alternative to the more normal 1/2" lag screws to house band or rim joist method.

Andy.


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## ront02769 (Nov 28, 2008)

Gbrakins, deferring to a Blue Devil's better informed opinion. My reference was actually supposed to highlight the use of Dek Blocks (or similar) as a short-cut around digging proper footings for a free-standing deck, allowed some places, not in others. 

ron


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## Knucklez (Oct 21, 2007)

i would never build a deck with anything less than 2x8 joist. we're lucky in NA, wood is cheap. pressure treaated from HD is about the same as anywhere else, there's only a few manufacturers that supply all. what i find that is different is the wood itself and the cost. HD & lowes tend to have scrappy wood.. splits, bends & twists. if you go to a lumber yard they tend to have straighter wood and guess what, it is often cheaper!


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## 8cuda (Mar 31, 2015)

Using the Span Chart for Southern Yellow Pine, 
2x6 joist allowable distance at 16" O.C. is 9'-9"
The max allowable post distance is 7'-9"

I guess my current design has a large safety of factor 

My choice for using 2X6 is that I can man hand that size of boards, as I will be doing the build myself.

Also, I can fit 2X4, 2X6, and 4X6 in my Honda Civic with rear seat down. I will pick up some boards on my way home from work each day.


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## Knucklez (Oct 21, 2007)

OMG, i hear you! i have a small hatch back as well.. but i put 2x10 12' long in there, stack them up and red flag the 6' that sticks out the back. that was a bit nuts..

i put my beams 8' a part cause i had 1' cantilever on one side and wanted to overhang the other side at random length so i could have joist sister up with another and keep going. means i bought a lot of 2x8 10' for the joists. but it was no problem to move them with just me doing the work and loading in my hatchback. 

don't believe me?


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## 8cuda (Mar 31, 2015)

Amazing and creative we are to get the job done :thumbsup:

I have not yet to venture the _"red flag the 6' that sticks out the back. that was a bit nuts.."_


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## shaftmaster (Mar 30, 2015)

8cuda said:


> Also, I can fit 2X4, 2X6, and 4X6 in my Honda Civic with rear seat down. I will pick up some boards on my way home from work each day.


Save yourself some hassle and your car from wear and tear. Order what you need from a lumber yard and have it delivered. You will also gain options as far as length of boards, etc.


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