deck repair/rebuild


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Old 01-15-02, 02:43 PM
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deck repair/rebuild

i have a sagging deck. the house is preowned. there are minimul supports on the outer edges with out girders in the center.

the deck measures 30'l x 12'w.

i want to install a girder supported by columns. my plan is to measure off the foundation and dig holes, pour cement and add caps.

the plan is to jack up the existing deck, lay in a girder and place supports of 4x4 or larger.

what is available for digging holes besides a manual post hale digger hat will make acceptable holes?

how do i calculate how many bags of premixed cement and what kind should i use?
 
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Old 01-15-02, 05:19 PM
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First, is the deck attached to the house with a ledger, or is it freestanding? If it is attached, you will need 2 girders running in the 30' direction. If it's freestanding, you will need 3. (And I am assuming that it projects out from the house 12' and runs for 30'.) Layout where you will need the supports. They need to be about 5' apart along the girder. Dig out holes that are about 18" square and 4" to 5" deep. Fill each hole with concrete and set a pier block into the wet concrete, then level the pier block. Don't worry about the pier blocks being level from one to the next (your posts will adjust for that), only that each one is level. How many sacks of redimix is needed will be determined by the size of the sack you are using. They generally come in 1/2 ft. (60 lb.) and 3/4 ft. (90 lb.) sacks. Each of your holes will need about 3/4 ft. Buy 4 or 5 extra sacks. you can always return any that you don't use.
 
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Old 01-15-02, 05:33 PM
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If you have the space to operate, gas post hole diggers should be available at rental places; they come in 1-man and 2-man models. The bags of concrete mix will tell you how much they will cover; as I recall a 60# bag of concrete mix covers .6 cu.ft. (could be off on that, haven't done any concrete work lately). Capacity of the hole would be depth of hole x 3.14 x the radius squared. Figure using inches and then convert to cubic feet (1 cuft=1728cuin). For example a hole 10 inches across and 3 feet deep would be:

36 x 3.14 x 25 (the radius, 5, squared) = 2826 cu in or 1.6 cu ft.

Then divide the answer by however much cu.ft. the concrete mix bag covers; for bags that cover .6 cu.ft you would need approx 2 1/2 bags for that size hole.
 
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Old 01-15-02, 09:07 PM
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Post hole diggers, at least the ones that the-tow-guy seems to be referring to, will dig an 6 to 8 inch hole. That's fine for setting fence posts, but you don't want to bury a support post for your deck directly in concrete. That is why I suggested the pier blocks. I have put up over 100 decks the way I mentioned and have NEVER had a support post rot.
 
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Old 01-16-02, 05:16 AM
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We must have been typing posts at the same time, Lefty. I was assuming his method was similar to yours when he said pour concrete and add "caps". Knew someone would be along to expound on the particulars of the project, I was just answering the two questions he posed. Also, I don't think he indicated where he lives. The pier block on 4-5" slabs would certainly work here in SW Fla where we don't have to worry about freezing weather, but is it okay for the long term in colder climates?

By the way, one of the funniest things I ever saw was two guys putting in a fence line using a two-man posthole digger. It ran out of gas with the auger about two feet in the ground so they left it standing in the ground and refueled. Well one of the guys went to his pu truck for some water and the other guy grabbed one handle of the digger and pulled the starter rope. You guessed it, the handle slipped out of his hand, the auger stayed stationary in the ground and the power head spun like a merry-go-round until they could manage to hit the kill switch.
 
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Old 01-16-02, 02:26 PM
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deck repair/rebuild

to: lefty and the-tow-guy
Thank you for the input. I can check with a mason on the recommended footing depth for my area. 2' rings a bell. Trenching for conduit is 30" with 2' of cover (I work for SBC/SNET).

tow-guy: The location is in Norwalk, CT + / - 40 miles east of NYC along the coast of Long Island Sound. We set the anti-freeze for max of 20 below 0.

Lefty: The deck is presently attached to the house with joist hangers; the joists are 2 x 8 (they measeure 7 1/2").
When you say one girder or two girders, do you mean to double or triple up with a main beam running 30' long about 6' from the house (or closer to the end of the deck?). Or parallell runs, one say at 4' out and the other at 8 or 10' out.
What size girder is recommended; 8, 10 or 12".
The joists are face nailed at the far end into a 2 x 8, which is sitting on 4" x 4" wooden posts standing on blocks laid on the ground (we don't have big parties on the deck).
 
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Old 01-16-02, 04:26 PM
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THAT Norwalk -- I was thinking the one in So. CA. That will make a difference because of the frost line. Because of that you should forget what I said about the pier blocks. Instead, do as the-tow-guy suggested and rent the auger. Go down 24" to 30" with that. Fill the holes with concrete and set a Simpson EPB44 post base in it. This will allow the post to stay above the concrete and still be solidly anchored to it.

Since the joists are attached to the house (I would hope with a ledger), measure out either 5' or 6' and run a row of posts parallel with the house, and a second row out either 10' or 12'. The difference will be whether you want to cantalever the last 2' of deck, of set the outside girder flush with the edge of the deck. (Either way is fine, though I find using the 2' cantalever usually works better.)

On top of the 2 rows of posts you will run a girder parallel with the house, in the 30' direction. That girder should be at least a 4X6, and the joints in it need to occur centered on a post. Attach the posts to the beams with Simpson post-to-beam connectors.

Your joists (2X8's) will rest on the top of the 2 girders, and Simpson makes several connectors that can be used there.

Good luck with the project, and don't hesitate to ask questions if you want anything clarified or run into other problems.
 
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Old 01-17-02, 02:14 PM
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deck repair/rebuild

Lefty,

Thank you for the input. I appreciate your efforts.

I belive I have enough direction at this point.

Don
 
 

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