Plan on building a deck? Reduce
the chance of water infiltration—install the decking a few inches below patio and
entry door thresholds. It's true that decking installed at the same level as
the interior flooring looks great and makes for a smooth transition, but unless
you live in the desert, it's not a good idea.
When decking is installed up
tight to the bottom of a door, that door is not only subject to falling rain,
but also to the rain that splashes off the decking. And if you live in a
northern climate, even a modest snowfall will expose your door to the powerful forces
of water melting and refreezing.
Back when I was a siding contractor,
water infiltration at doors with flush decks caused all kinds of problems. We frequently
found rotten doorsills, damaged flooring and the beginnings of serious
structural damage on houses only a few years old. There's no magic number, but
I would recommend a minimum of 2 in. from the top of the decking to the bottom
of the patio door threshold. I opted for 3-1/2 in.
Many doors have a sill or
threshold that needs to be supported, so don't forget to install a kick plate
under the door. I ripped down a piece of decking trim board and painted it the
same color as the door. Kick plates do get "kicked." Eventually, I am going to
replace mine with a PVC or composite board—either will take a beating and look
great without my having to stain or paint it every year.
— Mark Petersen, Contributing
Need more advice about
building a deck?
Rebuild an Old Deck With New Decking and Railings
Attaching a New Deck to a House the Correct Method
How to Build the Deck of Your Dreams