the deck

[jasdoit]

Alright, looking to put a deck on the back of the house. Here are some basic specs:

A) 14' x 14' total size

B) total height from grade: 13" ( not very high off ground )

Couple questions or minor concerns that im looking at.

1) Because of the low total height of the deck I'm wondering about the 4x4 post? My first thought is to use 8" tubular forms for the concrete footings and rest the post on top BUT being the post would only be roughly 9 or 10" tall would that be an issue?? In this case, is it better to just run the post straight into the ground through the concrete??

2) Also, Being I've never really used a string line and really never worked with lining up post, what kind of tolerance am I dealing with or can get away with? This deck will have 2 rows of post with 3 post in each row, when laying these post out, is it possible to be off say 1/4" or 1/2" off the mark and still work? If the beams are running parallel with the house, if one end of the beam is 1/4 to 1/2" farther out than the other side from the house, is that considered good enough? Now, I know the closer the better but is there any forgiveness at all? I guess whats really getting me is not only are there 2 rows of post but there are also 2 single posts in opposite areas of the deck as well. Position of these is concerning me.

I guess all Im trying to say is if Im off a little or out of square a little is it still gonna stand strong? And are 10" post too short to work with?

thanks to anyone who replies!

 

[Wuzzat?]

2) Also, Being I've never really used a string line and really never worked with lining up post, what kind of tolerance am I dealing with or can get away with?

The kind of level that uses a garden hose can give 1/16" accuracy. Grainger publishes the accuracy of some of the levels that they sell.
Try for high accuracy, you'll always end up worse. Ideally your reference elevation should be in the center of the deck so the longest distance to any post is √2 x 7' = ~10'.
To check square, check that both deck diagonals are equal, at ~19.80'.

IMO leveling this closely is mostly for appearance.
I hope the horizontal surfaces close to your deck are level, otherwise you might have to disguise the differences, which may be visibly objectionable. The trick in this case is to make it so the eye is not drawn to this area.

 

[oldognewtrick]

1/4" on decks is pretty close. Make sure you have fall in your stringers away from the house so water doesn't run towards the house. If you have any doubts about framing and structure, google deck designs, go to the library or get a deck book from any big box supply store or lumber place. Post pics of what you build, we'd like to see.

 

[jasdoit]

ahh this is great, thanks for the replies! OK, it seems I might have mislead you guys into what I was thinking but replies about leveling, meaning the horizontal direction make sense so thanks for them. But I guess my real concern is accuracy going the other direction, let me see if I can explain this right.....

visualizing the beam that is parallel with the house... having 3 post supporting that beam, a left, center and right post looking down from the sky. What if when poring your concrete into the dug holes then using j bolts as anchors for the post, what if you get those j bolts off a bit to where when you attach the post to the j bolt you have say the left post 1/4" to a 1/2" or even 1" further out from the house than the right post. Meaning, if I were building a sandwich style beam I would technically have to push or force the left side of the beam over to meet the post in order to connect it.

I guess if you have your string lines set up as a guide and making sure the string is parallel with the house while you are inserting the j bolts you should be alright?!?!

I guess the answer Im looking for is...... naaahhhhhhh, all you have to do is measure out with the tape measure where you want it to be and you're good! haha.

It's just when you see the vids online and read the books it seems everything is extremely accurate where I know when you get out there it tends to be a different story.

Thanks again, Ill be sure to post pics when this begins!!!

 

[inspectorD]

I know...oh ask me ...i know...

What I do to get all my j bolts in a row is this.
Dig all your holes in your line with a string.
By a 2 x 4 the length of the beam. Or connect 2.
Drill your holes where the j bolts will go in each peir while the 2 by is over each peir along your line.

Install each j bolt in a hole to hold it in place as the concrete dries.
Now the j bolt is 1-1/2 inches over the concrete, and they are all in line for your beam.

I buy a PT 2 x and use it for blocking if I need any in the framing.

Have fun.