Deck support footings?


I'm building a 15 x 22 foot wood deck near the side of my house - pressure treated pine 2x4s. The deck is very low to the ground - there's a very slight ground slope, but at the most with the deck level there's maybe only 3-5 inches of clearance from ground to the bottom of the runners. The ground is reasonably well-drained, and here in Texas there are no frost line issues, so rather than digging footings, my plan for footings was to use some type of concrete pavers or stepping stones laid out on the ground every two feet along each runner to support the runners - with two feet between each runner - because of the low ground clearance issue, I was going to use the same 2x4s as I'm using for the decking, laid down on their side versus on end. What type of support form would I need - what type of footprint should the laid-on-the-ground platforms have? Thanks!
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You shouldn't use PT for the deck. That's a hazard to people who use it. Ever gotten a bunch of splinters from PT wood? Use PT for ground contact only; not for the decking.
Decking is usually 2x6; NOT 2x4. Same for joists (what you call "runners")
Pavers in place of footings is probably gonna work if you don't get it inspected, but footers sunk into the ground would of course be the wiser way to go.
Texas Yankee wrote:

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Thanks for the info - I've used PT for a couple of other decks I've done and I was OK with the look and feel; as far as the materials, the 2x4 is MUCH less expensive (per square foot) than 2x6, at least where I am, so I'll do the extra work and use 2x4s instead of 2x6s.
But what do you think about the size of the pavers I'm gonna use for footings - what size (footprint) should they be? Thanks, again!

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in the 12-18" range. I presume you are talking about 2" thick?
Dave
Texas Yankee wrote:

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Yes - if I can get something like that - what I've seen at HD looks like it's about 1 1/2 inches thick.
Thanks!

and
MUCH
do
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Home Depot and Lowes and others carry this or a very similar block. This would not require any additional support.
http://www.nitterhouse.com/masonry/products/specialty_products/deck_blocks.php
Texas Yankee wrote:

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wrote:

I've used those before.. they were very slick, but you need a bunch of them... If you follow the directions that come with them, you get a very solid deck without cementing 4x4's into the ground.. YMMV
mac
Please remove splinters before emailing
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I'd have to consider putting in a concrete patio instead. Much less maintenace over the next 100 years. Also no chance of wildlife taking up residence under it.

With the potential flex of a 2 x 4 you may need more support on some of them. HD sells a block made for decks with no footings. They can be dug in a bit to make everything level. It would be worth checking them out. I've seen them used, but have no first hand experience. I needed 48" deep footing where I live.
What type of support form would I need - what type of footprint

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Texas Yankee wrote:

..snip..
You might be creating a challenge (maybe even a nightmare?) here if I understand correctly - it sounds like you plan supports under the joists at 2ft o.c. (on centre) for the joist supports that are themselves 2ft o.c. - meaning you are going to have almost *100* these support pads!! *and* then attempt to make them level across the full deck field!! ?? Really??? You don't indicate if these pads would be placed on a compacted base of some form or directly on existing grade material.
It also sounds like you plan to lay your 2x4 joists on the flat (wide side down) free span across the 2ft o.c. supports. Unlikely to exceed any load capacities (check tables) but I'd worry about bounce and spring.
To be honest, I suggest you discuss your plans with even your supplier and look at options for your needs and against constraints like your budget and the maximum off grade height that you desire. Most locales don't have regulations requiring permits and inspections for this type of low and detached deck but still many building officials would take the time to give advice and recommendations for a safe and solid construction result.
Ed made a good suggestion earlier to build this out of concrete and I assume not necessarily poured concrete like the garage floor but any of a wide range of finish choices going across many patterns of paving stones, flagstone, patio stones, etc.
A possible option to retain this with a wood surfaced finish in your area with good drainage you say, you might explore building the deck on grade on a properly compacted built up granular base and using your 2x4 runners as sleepers on this and decking across the sleepers. But, the sleeper material must be rated for ground contact and insect consideration is still there. I have seen this done for decks only about half the size you plan so definitely again check around locally for experiences and suggestions.
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I missed the part about him laying the 2 bys on their sides. If I'd noticed earlier, I'd also have advised him of the folly of his plan. :)
Dave
Ed & Sue Beresnikow wrote:

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It may depend somewhat on what type of soil you have where you want your deck.
I have rocky soil 1-2 inches deep on solid limestone(Austin area) and have supported pretty good sized storage building with concrete blocks leveled.
But I have to be honest: I hate decks. I have had 3 on three different houses in two states and they were all a pain in the rumpus due to maintenance being required from day one and on. All three were builder constructed but had blatant mistakes in them(decking turned with wrong side up, fasteners coming out, ragged pieces used that were bent, etc) The deck in Colorado was only 4 years old but was coming apart due to the activity of the sun up there in the high altitudes.
If you can possibly swing it concrete in some form is the way to go. You can do almost anything with it these days in terms of finish. And doing your own form and pour would not be too hard if you studied it and got some help from friends who had done it before. Or hire it done.
Decking materials are very expensive and will form a structure that will need maintenance to even stay in fairly good shape.
As an aside: one of the remodeling radio shows in town has a guy that has been on for years and he is saying that the new ground contact and exterior preserved lumber products react with some of the galvanized fasteners and decay them in 2-3 years. Yet another reason to do concrete.
Your choice of course but had to sound off a bit. Good luck with whatever you do.
RonT
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Texas Yankee:
I am a contractor in San Antonio, and I know how much we all love our decks down here in Texas. Concrete is for patios and for porches. Not for sitting 2-5 feet off the ground with a cold one to watch the sun set on the hill country. I personally like the organic quality of sitting on a wood deck an the feel of it under my feet.
A couple of thoughts: When I put down a deck frame work, cut away any vegetation, then go 4" below the frost line/vegetation roots with a 2'X2' hole. Depending on where you are, this is usually not too deep. I line the hole with sand to level the bottom out and put a 2'x2' concrete pad down. Then I use the deck blocks. I use 4' centers all around for this, and never have complaints.
Plan on an easy to apply wood finish every 2-3 years. When I build one out of any material, I tell the folks to get a cheap pump sprayer and a 5 gallon bucket (depending on deck size) and spray down the clean deck 30 days after we are finished. Spray again in six months. Spray again a year. Then as needed. I have seen well maintained decks stay around for 25 years and still look great, and zero maintanence decks go to crap in 2-3 years.
But the best advice I could think of for you is to go to the library and take a look at any of the 10,000 books on deck building. They are everywhere. They are at Half Price books. They are at Lowes. They are at Home Depot. In fact, I don't know if they still do it, but they used to do the design work as well as the material take off at Home Depot for free.
There are also some great programs around out there that you can buy that help you design your deck for appearance as well as structure.
You will hate yourself if you are pennywise and pound foolish on this. I know... I make a killing fixing homeowner built decks/gazebos/storage facilities/shops and all other manner of home made monstrosities where the "builder" doesn't plan or execute well. Slamming a pile of lumber together like they do on the home shows just won't cut it.
With so much information at your fingetips you should take another couple of weeks and work out all the logistics before you buy a board.
Robert
BTW... where in Texas are you?
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Howdy!

I'm in Maryland, and the deck I built most of ten years ago has required zero maintenance to date. I used Trex for the decking (and the tops of the railings). The support structures are all PT of the appropriate size.

[snip concrete recommendation]

No. A quick google search finds that the ACQ preservative demands a better grade of fastener -- either with a heavier coat of zinc, or appropriate types of stainless. Learning that took me five minutes.
yours, Michael (catching up on rec.woodworking)
--
Michael and MJ Houghton | Herveus d'Ormonde and Megan O'Donnelly
snipped-for-privacy@radix.net | White Wolf and the Phoenix
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