Cover the gap between the deck and the ground with a skirt made of pressure treated or composite plywood.
How to keep bugs from coming up through deck floor.
In order to effectively protect against bugs a screen porch must be completely enclosed but if your porch wasn t well built from the start it is often the deck floorboards that were overlooked.
So it has the basic kind of 2 4 style decking on the floor.
What kind of bugs and how high is the deck from the ground.
It seems screening the underside of the joists has the potential to trap debris that falls through the cracks.
The crawlspace beneath is open as it is a post on pad foundation.
Traditional decking has a 1 8 or 1 4 gap between boards which is more than enough room for mosquitoes or other bugs to crawl through.
In addition there are various chemicals that can be applied to the deck boards that not only protect it agains weather but keeps the bugs aways i cant remember the name right now but if you search it on the net you can find it.
My first thought was to lay marine grade plywood over the decking but given the potential for water to enter through the screen and lay on the floor i m a bit leery.
We have a porch that was built around an original deck.
The underside of a deck can provide a nice shady area for a variety of crawling creatures to make their home.