setting deck posts on a steep slope

[MikeT]

I am trying to think of the best way of setting my deck posts on my sloping lot.  What I was thinking about was creating a 16'x14' ( the size of my deck) frame out of 2x4s, hanging mason's string from the places where I want to post to be, and setting it at the lowest point of the house where I can temporarily affix it.  Then I would level it and tack in some 2x4 support posts.  Then I would go to where I had the string and tie a plumb bob to it and mark the spots where it lands.  That would be the place where I would want to dig and place my posts and in theory it would be in the same place as it would be for the final placement of the deck which is some 10 feet higher than the temporary frame I am tacking in.  

Does this make sense as a tactic?  Does anyone have another, better way of doing this?

thanks,
mt

[PEG688]

Lot of work but it would get your post right in the corners IF they had to be . Remember to square it up as well of course.

It's alway a PITA on sloped lots .

If your using beams and your post would be under the beams a cantilever could work so as long as you where "close"  and  of course in line and parrell to each wall , if that make sense :-/

 

 What you could also do is set the top two post plumb and temp them up or pour in first then pull a tape off them , fairly level or level , knowing you diagonal measurment  would be required , two tapes one for lenght one for the diagonal #, then plumb bob down from that "point" .

BTW the diagonal measurment  for a   16' x 14' building would be , 21' - 3 1/8"


Edited cuz I can't speel dimension so I used a different word  

[MountainDon]

For what it's worth here's how I located the four posts on my gazebo. http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1166598189/60
scroll down almost half way

I started with the post at the highest corner, the NE. Dug the hole, dropped in the post, tamped the earth back in place. Then I measured across to the NW position, dug that hole, dropped in the post and shoved it this way and that way until it was plumb and the correct distance from the first post. I clamped a straight 2x4 from one to the other and also used 3 diagonal braces from the post to the ground to hold it straight. Then I pounded dirt again, all the while checking for plumbness.

On to post three, the next lowest point, the SW corner. Used more 2x4's clamped to the posts, measured a lot and braced the post again. Dug and set the fourth post. These last two holes were made a bit oversize to allow for jiggling their positions until the sides were equal, the diagonals within less than 1/8 inch, and the posts were braced plumb. Pounded dirt again.

[edit]To clarify a point; the 2x4 that were temp clamped to the post along bottom sides were positioned level. Then using the 3:4:5 triangle method the third and fourth posts were jiggled into position and the whole thing double checked by measuring the diagonals. [/edit]

[PEG688]

Thats pretty much what I tried to discribe , BTW Mtn D it looks good ,  yer doin a fine job  8-)

[MikeT]

Thanks PEG and MountainDon.  I made a copy of your suggestion and will share it with my smart coworker, my father, who will help me this weekend.  We will figure this out.  

mt