[TINTIN]

how do i attatch uprights for a pergola on existing decking?

[Ice]

Any chance of a photo?  The decking, not you.

[arugula]

You can get this sort of thing but they don't look great . How about removing some of the decking planks and replacing some of the posts in the framework underneath then replace the planks on top or add new uprights outside the planked area?

[noshed]

Sounds like a recipe for slippery decking...

[arugula]

True enough. When we had a pergola, it wasn't over decking....

[Steven Rowe]

how do i attatch uprights for a pergola on existing decking?

All depen on what size off framework your going to put up and the size of timber, if your going for a bigish size, id lift the deck boards where your supports are needed and dig  holes and concrete them in , when i build things like this i usealy use 4''x4''x10ft posts for supports and 5''x2'' boarding for the main frame ,