Help!!Advise on what to do...deck post holes..

Old 03-29-10, 03:31 AM
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Help!!Advise on what to do...deck post holes..

i decided to extend my 12"x16" deck to 14"1/2' x 22"..after i was quoted a price to build a brand new deck, that wasn't in the budget. i live in Pgh. PA

the existing deck is maybe 1 inch off the ground on one end. and maybe 3 or 4 inches of the ground on the other side. the addition will be about the same.

i rented a gas auger over the weekend, dug in but couldn't get the postholes very deep with out hitting rock. dug some of the rocks out with a bar. i got most of the holes at least 1 foot to 1foot 1/2 deep. some deeper, but not much.

dummy me, i was in a hurry, and said screw it (don't know why) and went ahead and cemented them in(4x4 post with cement in bottom of the hole and around the post, seems solid) where they were supposed to go...woke up the next morning, and got myself all worked up thinking i screwed up...

my question is: since the deck is so close to the ground do i really need to worry about what is already done? or do i need to redo the work? talked to a friend said "3feet in Pgh is ideal cause of the frostline, but 2foot would do."

(i set a swingset with 1foot of concrete in the same yard with no frost heaving.)

Any advise or elaboration would be appreciated..thanks
Old 03-29-10, 03:51 AM
Join Date: Jan 2010
Location: North of Boston
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I don't know the correct depth in Pittsburgh, but you will notice any frost heaves in a deck addition much more than you will with a swing set.

If you want a quality job that will improve the value of your house, you should pay attention to the guidelines. It's easier to correct it now than after you build the addition.
Old 03-29-10, 06:19 AM
Join Date: Oct 2008
Location: New England
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This is one of those easy jobs that's not so easy. Our Red Sox Fan has it correct, the frost is probably there, but the deck will show it more. But even if you went down 5 feet, frost can still lift those posts. The size of the pad you put at the bottom of the hole and the material the post is made of, contribute to the frost potential. Other issues like the soil, drainage, and how the other posts were installed need to be considered. If the other posts are floating with the frost and you anchor the new ones below the frost line, part of your deck will rise and part will stay put.

There are so many things to consider, that the simple approach may be to put it together with screws and see what next winter looks like . The only real way to be sure what you are doing will work is to install all of the supports, old and new, so they are all correct and the same. Obviously something you want to avoid.

Not sure the extent you want to go into this so I'll wait to describe more options.

Side note, one of the benefits of Mike Holmes doing his thing on tv is we are seeing what needs to be done to correct short cuts. Not picking on you, but I can see Mike coming in next year and throwing all of your hard work in a dumpster, excavating half your property and building a deck with BBQ, hot tub, trellis, and built in lounges. I wonder who pays for those projects he does?


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