Another Deck Question...

[pslamp32]

Well I've decided to take a stab at building a deck. I've decided to use traditional 'footers' (I think that is what they are called). The permit guy said that I needed holes 18" deep X 18" wide. I think I'll try to use those pier things so the wood posts are not in contact with the ground. Can someone detail exactly what I do from the point that the holes are dug for me. Most instructions I've read seem to skim over this part as if it is common sense and It probably is but... The deck will probably be ~20 X 12. I don't want to attach the deck to the house so I believe I'll need at least 6 holes right? At the highest point I expect the deck to be~ 4 ft. off the ground. Most places will be between 3-4 feet I believe. What size dimensioned lumber do I need for the girders and rafters? I thought the permit guy said 2 X 10. Seems a bit like overkill to me. That would be 19" above the posts before decking so 20.5" from the top of the posts to the top of the deck right? How far out of the ground do the piers stand? Alot of questions I know. Sorry...

 

[Jim M.]

Peter,
I was in the same boat last summer, try this link, it answered most of my questions better that the two stupid books I'd bought.

http://www.decks.com/article263.aspx

Mine was free floating and only 10x10'; my soil is mostly sandy-loam, so I used cardboard tubes filled with ready-mix and went down 3' with an anchor plate about 3" above soil line. I framed mine with 2X8' and it's only 14" above grade. Feels real solid, but I don't think I'd ever make a living out of doing them:eusa_doh:
Hope that helped, Jim

 

[Nativespec]

Just put some gravel in the bottom of the hole and then tamp the gravel with a 4x4 post.
Also, it is not so simple, you will need to refer to code and calclulate spans, size of lumber and all depends on the number of footers. Decks changed and are now built like the rest of the house since they started failing around college campuses in great numbers when their strength was put to the limit.

You will also need to use 5/8" bolts or cut let-in's into the posts. Free standing decks are a good idea to let water drain away from the band. The only problem is that you may hit the footer of your house when digging new post footers. If this is a problem, you can use cantilevers in your framing (up to 2') to bridge the gap between the footers of the house and the deck.

I have a fairly recent code book, but you really need to understand how it all goes together-it is not all that simple and can be very expensive to tear down and rebuild.

I built about a 600 sq ft deck for a friend of mine last year and it cost around $9,000-but it is a good looking deck

David

 

[Travis Porter]

I personally would not use the concrete piers. You can buy steel fittings that will fasten to the concrete footers and the posts as well as keep them off the ground.

 

[Gotcha6]

I personally like the dug & poured piers. I pour 6" in the bottom & let it set up. Then I can set my posts on top of it & move them around to get them square. I can also cut them to proper length to work with. A little temporary bracing & pour up the sides. You'll then have the entire bottom of the post encased in concrete to take the load & keep it from wicking water up from the bottom of the post hole. Even though you'll probably be using 'ground contact' lumber, I doesn't hurt to protect it as much as possible. The concrete in the bottom also helps spread the dead load to the soil better.

 

[Nativespec]

I like the quickset concrete, hate using temporary supports. I use it sparringly and then poor the regular mix on top.

David

 

[Mark Anderson]

here is the but-backward way i do it, dig the hole for the footer down below frost line ot the 12" minimum.

biuld the deck complete with post with a petistal on the botom (do not cut the botom of the post, leave the treated end on it for protection)

use tempory (2-2x4 spruce, cheap). to suspend the deck and post over the hole, the post should "hang" 6" above the botoam of the footer hole.

nail a strap at the bottom of the post that hangs down into the hole, i use brick ties as the shpe will lock it into the concreat. this is required for up lift. ( if the wind is stong enough to lift my 14x24' deck it's gong to be the least of my problems....but my deck is tied down lol)

make sure deck is leavel and the post are plumb,

call for the footing inspection if required in your county.

pur concreat just high enogh so the legs of the pedistal are locked into place, i donot imbed the bottom of the wooden post in the concreat, i have seen too many post decay due to the moisture that will be locked in by the concreat....treated or not.... also if the wood swells it would slpit your footer.

 

[coastal1]

Hi, Peter,
I don't know what type of house you have but If it is brick I would suggest using block or brick piers. I've built several and the pier adds to the look of the house as well as stability for your corners. On the inner spans not so visible from outside you could lay blocks with out the brick. Of course you would still need a footer for each column but the brick would be alot more asthetically pleasing than the treated or piers.

 

[Phil in Apex]

I finished building a freestanding deck about a month ago (See my posts for a full pictorial detail). I laid out and dug all my footing holes first and once they were inspected I poured all the concrete at once. For the main support posts, I tamped down about 3-4 inches of crushed gravel before I poured the concrete.

Once the concrete was set, I set up my posts, beams, and cross beams. My town does not require the post to be anchored in any way to the footing. They say it is fine just resting on it. That was not good enough for me, so I used some simpson galvanized L-brackets and anchored one end to the post with a 1/2" galv. lag bolt, and the other end into the concrete with a concrete anchor.

This was much easier than setting an anchor in the concrete, because then you are locked into that location for the post. I was able to tweak my post locations and get them just right before anchoring them down.

As for spans and details, go to the library (or buy it) and check out the fine homebuilding book on building decks.. It is by far the most detailed and will answer most of the questions you have. Of course, go by local code before any book... The folks at the inspection dept in my town gave me a copy of the NC code for decks which answered most of my questions similar to what you are asking.