it is best to support the joists from underneath with 4x4s. This is going to require two peope to set up. one holds a 4x4 against the bottom of the joists and the other person cuts another 4x4 to go underneath on each end. this will support from underneath and you can access the roof without compromising the structure, or worse, your safety.
In order to build a deck on your enclosed porch you will need to know how tall you plan on building your porch as well as if there are any city restrictions. I suggest downloading free porch and deck design software as it includes the price of the required materials as well.
The most simple porch decks are probablly the ones that are wooden. Those are nice and cheap. You can find your porch deck plans cheap at the home depot.
veranda deck patio
deck
Porch
balcony, deck, stoop, veranda
A veranda or a deck are other words that could be used to describe a raised porch.
porch, deck
Screened in deck plans can be found on some websites online. Here are a few I've found, www.front-porch-ideas-and-more.com/screened-in-porch-plans.html, and at www.front-porch-ideas-and-more.com/build-a-screened-porch.html.
ehow.com has a range of tutorials on how to do certain things and building a Porch deck is one of them, you should check it out at ehow.com, they are really good ones as well
Porch/Sun Porch Patio Lanai Deck Terrace Balcony Terrace Piazza/Piazzetta Gallery/Galleria
yes