Redi-Footing deck posts

[tjbnwi]

I have this, I don't recall seeing an adopted code;

http://www.awc.org/publications/DCA/DCA6/DCA6-09.pdf

I recall something from the University of Virgina also, ill have to see if I can find that.

Tom

[Dutchman]

Hmm, must be a Maine thing. Or, it was an LSD glitch in my synapse from the college days and I'm seeing things.

[DonMirabito]

DG,
IIRC you are in Michigan. I'm thinking you are in an area that has a deep frost line and have to set the footings pretty deep like maybe 4 feet or more. Is that right?

Do you follow the IRC in your area? If so, check out the various sections in chapter 3 and requirements for distributing "ALL" loads to the ground. Also check out Chapter 4 TABLE R401.4.1.

The above sections will dictate how big the footings need to be and IF you can use piers at all, how close they need to be spaced. Your soil conditions may dictate you need a frost wall or some other type footing/foundation support. IMHO, it isn't about what the post gizmo can do so much as how heavy is what it is supporting relative to these design constraints. For example, if you are putting these things on soil with 1500 pound strength per sqft then that is all you can support IF the footing has bearing of 1 sqft. These posts do not even have that much bearing!

Hopefully this is clear...

Don

[Greg Di]

The above sections will dictate how big the footings need to be and IF you can use piers at all, how close they need to be spaced. Your soil conditions may dictate you need a frost wall or some other type footing/foundation support. IMHO, it isn't about what the post gizmo can do so much as how heavy is what it is supporting relative to these design constraints. For example, if you are putting these things on soil with 1500 pound strength per sqft then that is all you can support IF the footing has bearing of 1 sqft. These posts do not even have that much bearing!

Don is on track. Any footing/pier/whatever is only as good as the soil, so unless you have a soil test at the job site, you have no idea what the soil is capable of holding.

This is what appeals to me about helical piers and why I got involved with Techno Metal Post. Our installations are each verified to handle a specific load based on the quality of soil. If the soil is weak, we keep going until the soil is strong. At the end of the install, I can tell you exactly what the helical pile will hold--no guesswork--it's the most scientific way to install a foundation system you can hope to get. Numbers don't lie.

[magna111]

Usually... http://forums.jlconline.com/forums/s...ion+calculator

[dgbldr]

I have this, I don't recall seeing an adopted code;

http://www.awc.org/publications/DCA/DCA6/DCA6-09.pdf

I recall something from the University of Virgina also, ill have to see if I can find that.

Tom

Tom, I haven't seen that document before, but it looks suspicious. On bottom of page 7, it says ALL deck posts must be 6x6 or larger. That precludes the Redi posts. Right after that, it says deck to post must be bolted and shows the double 2x beams sitting sistered on a single side shoulder cut (haunch).(Fig. 8.)

The pictures you posted in #3 violate all these. I'll have to read the code, but I'm a bit skeptical of this document.

[dgbldr]

The above sections will dictate how big the footings need to be and IF you can use piers at all, how close they need to be spaced.
Don

Yes Don, all that means is that on poor soil we'll need more posts. Not an issue, and our soils are generally good. I'm trying to establish whether the Redi posts have general merit and whether it makes sense to try them out.

You are indeed correct in that they have a fixed, and small, footprint. You can't just make it bigger diameter with the next size up sonotube :)

[MarkMc]

Will your AHJ accept them? Have run some $ numbers on your typ job vrs your usual methods and say the techno posts? Bearing in mind that any ability to get right to work on them may well be mitigated by, well, not being able to get right to work on them due to numbers to be set or status of the rest of the job.

[tjbnwi]

Tom, I haven't seen that document before, but it looks suspicious. On bottom of page 7, it says ALL deck posts must be 6x6 or larger. That precludes the Redi posts. Right after that, it says deck to post must be bolted and shows the double 2x beams sitting sistered on a single side shoulder cut (haunch).(Fig. 8.)

The pictures you posted in #3 violate all these. I'll have to read the code, but I'm a bit skeptical of this document.

As I stated I have never seen an adopted code. I believe, what I linked was a proposed code document.

It is not a proposed code document, but a combination of code and what they feel is best practice.

I went and looked at the document again. It states any code citation is bracketed. The 6x6 post and the notch is the AWC recommendation, not a code requirement. The code sited in the post section is R402.1.2, that only deals with the treatment of a cut end.

I much prefer the way I shoulder the post, far less chance of a split going straight down from the notch. The support tongue is still 2-1/2" by the depth of the beam ply.

Tom

[dgbldr]

Tom, we always put our beams on top of posts, with saddles, no shoulder cuts. So I was a bit curious about the shoulder cuts and asked my engineer.

He told me that the reason they show the single-sided shoulder is that it's a beam. They also show a fastening schedule. The way you do yours is not a beam (at least in our neck of the woods it isn't). To call it a beam, the 2 plies have to be in contact the whole length and be fastened together over the entire length. Otherwise you have to engineer it as 2 half-thick single-ply beams.

[tjbnwi]

Thanks dg, I'll look into it.

Tom

[tjbnwi]

Dg,

I have discussed this with an engineer and a building inspector.

I do bolt the plies with spacer, every 32". The building inspector said he would pass the install. The engineer said it could be treated as a repetitive member. He will check into it and get back to me.

More to come.

Tom

[dgbldr]

Right. I'm not saying your spaced 2x beam is inadequate. I'm saying my engineer and my inspectors do not consider it as equivalent where a span table calls for a 2-ply 2x beam. It would have to have engineering calcs, including fastening schedule.

Perhaps one of the structural engineers here would care to comment.

I did a bit more reading on the Redi posts and I'll PM you my findings.

[KeithQ]

I know the last post to this thread is a year ago, but wonder if anyone has more redi-footing experience to add. Also, the redi-footing web site is down (it worked yesterday) and it seems their phone numbers no longer work -- does anyone know if they went under (no pun intended)?

Thanks...Keith

[tjbnwi]

I've done 2 more decks with them. Still like them better than concrete.

I have no answers to your questions.

Tom