I will be building a deck soon. Part of it will be over top of an existing concrete patio…4″ slab on grade construction. The existing patio is in good condition.
Two questions…will I have any issues if I support some or all of the deck on this existing patio using a post base with a standoff plate?
Secondly, what are your thoughts on post in concrete vs. attaching a post to a formed concrete base above grade? I have been told a lot of good and bad for each method…what is really the best way?
Edited to add…I live in NE ohio
Edited 3/25/2007 12:52 pm ET by timjea123
Replies
In your area of the country setting a post in concrete is probably not a good idea. If you must set it in the ground, set it on a block of concrete (preferably with a metal standoff) and then backfill with crushed rock (best) or plain soil.
What is wrong with the existing concrete patio--why do you want to put a deck over it? I'm probably not the only person who will see what you wrote and have this question.
Edited 3/25/2007 3:14 pm ET by Danno
Backfill with crushed rock will hold the post better than concrete, and has less of a tendency to rot the wood.
It sound as if some of the deck will be on footing and some of it on pad. Is this the case? If so you need to cut out the spots where you need posts and dig new footings through the slab. They would move at differant rates otherwise and cause problems. it would also not pass code. You need to float all of it or set all of it on footings. Its one or the other not both.
But in many areas a low deck isn't required to have footings, meaning you could put everything on pads. In our area a deck lower than something like 18" isn't subject to code at all.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
He said part of it would be above a slab. So he should support all of it the same to allow for proper movement. He is also in Ohio.
I would never put anywood ina footing unless it was a fence.
Edited 3/25/2007 11:33 pm ET by AllTrade
Surface piers would be roughly the same as on the slab.Not sure what Ohio has to do with it.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I would roto hammer 3/4" holes in the existing patio and put in adjustable 4" saddles for your beam run. Anything off of the patio should be dug down to footing debth for your area filled with concrete and set with a similar type of saddle.
"Rather be a hammer than a nail"
Bob