Top 10 Deck Defects
Decks are a great way to add outdoor living space to a home. It’s important to make that space safe and secure. Here are ten commonly found defects during deck inspections. This is not a comprehensive list, nor is it a checklist for code compliance. Be sure to check your local building codes for regulations on decks in your area.
- Improper attachment to the house. This is among the most serious defects that a home inspector can find whilst inspecting a deck. If the decks ledger board (Usually a 2×8 or larger board) is not correctly attached, the deck can separate from the house, casing collapse and potential serious injury. About 90% of deck collapses are caused by improper attachment. Ledger boards should be lag screwed or through bolted to the home, generally with 2 bolts staggered between each joist minimum. If you’re not sure your deck is correctly attached, consult a licensed contractor.
- Posts in contact with the soil. Very commonly decks are supported by 4×4 or larger posts set on concrete footers below the level of the soil. Ideally, footers should extend to soil surface to prevent the post from contacting excess moisture and decaying.
- Improperly supported joists are a common framing issue. Joists are the long supporting members that carry the decking. They should be attached to the ledger with approved joist hangers.
- Improperly supported beams or girders. Large framing members carrying the weight of the joists, beams and girders should be supported directly on the posts, not simply bolted to the sides.
- Poor or missing railings. Very often, decks lack requires railings. Any deck over 30 inches in height should have a railing that extends at least 36 inches above the deck surface. Most injuries related to decks are caused by railing failures.
- Inocorrect baluster spacing. Balusters are the vertical components that fill in the space between the top and bottom railing. They should be spaced less than 4 inches apart to prevent a child from getting their head stuck. Balusters should never be horizontal as children can easily climb them.
- Lack of a graspable handrail. Commonly, decks are built with a 2×4 or 2×6 handrail on the stairs that is too wide to grasp in the case of a fall. Hand rails should be 1 ½ to inches wide.
- Open risers. Children are at risk from open stair risers. The riser is the area between the stair treads. Openings in stair risers should be less than 4 inches.
- Lack of flashing against the siding. Flashing a deck against the house can be difficult and is often done incorrectly. Decks must be flashed and counter-flashed above and below the ledger. Failure to do so can cause water infiltration and damage to the house. This is a complicated issue and should be evaluated by a professional if there is any question.
- Paint hides wood decay. Very often older decks have been painted to improve their appearance and the paint may conceal defects. Probing can reveal some defects, but not all. Paint is often the sign of a deck on its last legs.