Decks are supposed to be beautiful and they are when designed, installed and maintained properly. Many decks have problems when they were not designed or installed/extended properly, often after as an add-on after a home is built. When the customer called initially, he was looking for some quick repairs before a party he was planning.
After the party we went back to deal with the source of the problems, and found a nightmare, especially for a house that was only 5 years young. The deck was not flashed properly and that's where the problem started. The siding and doors above the deck needed significant repairs, i.e. we rebuilt the door frames for 2 entry doors and replaced a sliding patio door. Even worse, the water damage traveled 4 to 6 feet into the kitchen requiring that floor to be replaced. Below the deck (photos #3 to 5), the siding, plywood sheathing and siding had to be replaced. The biggest challenge was replacing part of the sill plate that sits between the foundation and the exterior wall framing.
Decks Frequently Need Repairs Due to Water/Wood Rot Damage
Most decks provide the relaxation homeowners long for but occasionally there are problems. Most often deck problems are found where the deck is attached to the house. Water flows downhill, so precautions need to be taken to direct water from the roof, the siding and sky to travel to the ground without penetrating behind the siding. This requires flashing to be installed under the siding, wrapping over the ledger board (how a deck is attached to the house) and away from the house. When a deck isn't flashed properly, water gets into the wood and if unable to dry out, this creates an environment where wood rot happens.
All 3 of the decks shown below had problems where they attached to the house. What is most interesting is the range in ages – house #1 was more than 100 years old, house and deck #2 where built about 20 years before we repaired the deck and the house where photos #3 to 5 where taken, was just 5 years young. Let's look at each more closely:
- This deck was fascinating to pull apart given it's age. The damage was extensive but because the wood was old growth or virgin wood, with tightly-spaced (close together) growth rings, the wood resisted penetration by water and the organisms that cause wood rot. The boards we removed were at least 2 inches thick where today's deck joists are 2 inches when cut but they shrink to 1 and 1/2 inches when dried. With the quality of materials and workmanship, this deck was at least 50 years old versus today's deck average deck life of 20 to 25 years.
- In photo #2, the homeowner never saw the problem outside because it was hidden by vinyl siding. It was only when minor repairs were started in the basement, that they found several wall studs were almost entirely eaten away by wood rot. We had to add structural support to the house the entire length of the deck, replace insulation and all of the exterior sheathing. The deck itself was in fairly good shape given it's age.
- The homeowner attempted a short-term solution by putting up plastic insulation over their basement insulation in photo #3. They ignored the mold visible behind the plastic, never realizing it meant water was penetrating their home's exterior.
- Photo #4 shows how quickly wood rot can destroy building materials because this home was only 5 years old. This was a huge job, replacing damaged structural wood, along with the entire exterior including siding, water barrier, plywood sheathing, insulation and replacing/rebuilding framing for multiple doors and windows.
- Photo #5 shows the work almost completed under the deck, including a new vinyl window.
One way to avoid these problems is for do-it-yourself homeowners to hire a handyman to install the structural components of a deck while the homeowner adds the flooring and railings. This will reduce the number of decks installed without the proper flashing to minimize water penetration.
Read the rest of our series on water damage and wood rot repairs …