I would like to build a wooden deck over an existing concrete patio that is located between the back of the house and the garage. I would like to avoid breaking up the concrete patio if possible.
Just did mine. Had a new pad poured and new deck put on. If you are getting a permit, most towns will want you to dig 4 ft down and use 12" tubes - so you would have to break a portion for each footing.
However, if you are not getting a permit and your concrete pad is 4" thick, post footings (about $12 at HD) are drilled into the concrete (you can use tapcon screws - comes with it's own bit) and nailed into the post.
is height an issue, via any doors that are low to the ground going out to the patio.
i would just put down sleepers ( 2x4 on layed on its flat) anchored to teh slab and then fasten the decking to teh sleepers using 2 1/4" deck screws
Thanks!! Appreciate the help! Time to make some saw dust!
I would not anchor the sleepers to the existing deck, I'd just lay them on top of the concrete and let the weight of the deck hold them in place. You might decide to remove the deck someday and you won't want a bunch of holes in it then.
If the deck is going to be significantly above the slab, there are concrete post holders that sit on the slab and 4x4's can be inserted vertically or 2x horizontally. These look like a flat topped pyramid about 8" tall.
if the sleepers arent fastened down they will bounce and move all over the place as the decking is nailed down. with this happening there will be a line of nails that is no where near straight which is a small detail that gets critiqued by every person that walks on the deck
if posts going to be used its means several beams which will raise the height ofthe deck that much more
Question: aren't you concerned about leaving a gap between the concrete pad and the deck? What about moisture, insects, rodents, elephants, trash, leaves...in such a confined area?
Not enough space between the concrete & the finish deck for proper air ventilation, moisture control. High point allows 1.75" of framing under the threshold of the sliding glass doors.