The Great Deck Build: Part 2 (On Reflection)

Our home improvement projects often suffer from “mission creep,” as one seemingly simple project becomes hopelessly entangled with another one… or two. Our deck replacement served to illustrate the point perfectly, as we learned some very important lessons about proper construction and materials.

Lesson #1: Flashing is a must.
We expected that the demolition of our old deck would take most of the day. Imagine our surprise when it nearly collapsed after removing just a couple support beams. On closer examination we discovered that the header beams between the house and deck were nearly rotted away. So, too, was the wall anchoring one side of the deck to the house.

Related: Planning Guide: Wood Decks

The culprit: no protective flashing—that thin continuous piece of sheet metal or other impervious material installed to prevent water seepage into an angle or joint. Years of water seepage along the edge of the deck, onto the wooden beams below, and behind the walls of the house had caused the damage. Flashing would definitely be installed for the rebuild.

Rotted Header Beam

Lesson #2: Header beams can be replaced.
Header beams—also known as house bands, band joists or header joists—are the load-bearers of the house. If they are not sound and sturdy, they need to be replaced. Replacing ours was a fairly easy job, since the old beams were so decayed. Luckily the sill plate above the foundation wall, and the horizontal floor joists, were both OK.

We attached new 2” x 12” beams to the floor joists with metal lag bolts and finished off the new header with flashing (remember Lesson #1), being sure to overlap the edges and run a small bead of caulk for a tight seal. We then attached the 2” x 8” ledger beams for the new deck to the header beams, thereby making a solid anchor for the frame joists of the new deck.

New Insulated Wall

Lesson #3: Timing is everything—even in DIY.
Since we didn’t anticipate replacing the rotted exterior wall, we had no idea that we would be racing the clock to close it up before nightfall. (You know the old adage—don’t start a plumbing job late in the day or on a weekend, because if there’s a problem, there will be little recourse until morning—or worse, Monday!) 

In order to rebuild the wall quickly, we purchased eight-foot sections of 2” x 4” pressure-treated pine for the wall
 studs, 2” x 8” boards for the sill plate, 4’ x 8’ sections of plywood, and 4’ x 8’ sections of foil-lined insulating 
panels. We replaced the sill plate, framed out the wall with the 2″ x 4″s, and nailed up the plywood. We covered the plywood with the insulating panels and finished all of the seams and the edge of the future deck with flashing and caulk. By the time darkness was setting in, we not only had a brand new wall, 
we had learned quite a bit more about exterior construction than we ever expected.

For more on decks and deck building, consider:

How To: Stain a Wood Deck
Planning Guide: Wood Decks
Get Inspired: 12 Sensational Deck Designs