A free standing roof needs to have posts sunk into the ground.
Roof on a deck built on deck bloks.
Several commercial waterproof deck systems are available to create a dry space under a deck but rune stactic of adding a roof to a deck seems to be just as effective.
For corners deck blocks are built to accommodate 90 degree angles.
However many decks are right next to the back of your house which raises a few issues.
Because they are not recessed in the ground deck blocks keep your wood off the ground and prevent the problems that occur from columns standing in water for long periods.
Lay out the concrete pier blocks into six columns and three rows.
If your deck has a gap between it and your house this might not be a problem as you can simply build a stand alone deck cover.
A free standing roof can be built over a deck paved patio or concrete pad.
If it is next to a house or structure it should be secured to the siding or roof of that structure as well to keep it stable through high winds and lashing rains.
A 12 by 8 foot freestanding deck requires no sawing or hammering with a simple ladder frame and pier blocks.
Typical decks are designed to support 55 psf lbs per square foot.
Here are the details in case you d like to build your own building a deck with a roof version.
Joining a home made roof to your existing roof might require a level of expertise that you don t really have.
And it s inexpensive and easy to build using materials found at any home center.