How do I replace rotted soffit boards on a garage in coastal Saint John NB?

Replacing rotted soffit boards on a coastal Saint John garage is a manageable DIY project that involves removing damaged boards, addressing the underlying moisture source, and installing new materials designed to handle the Bay of Fundy's harsh salt air and persistent humidity.

Soffit rot is extremely common in coastal Saint John due to the combination of salt spray, high humidity, and temperature cycling that accelerates wood deterioration. The soffit boards (the horizontal boards under your roof overhang) are particularly vulnerable because they're exposed to moisture from both above and below, and coastal garages often lack adequate ventilation to dry out trapped moisture.

Start by identifying the full extent of the damage before ordering materials. Probe all soffit boards with an awl or screwdriver — rotted wood will feel soft and the tool will penetrate easily. Often, what appears to be isolated damage extends further than visible, especially in Saint John's salt air environment. Check the fascia boards (vertical boards at the roof edge) as well, since rot typically spreads from the soffit upward. Take photos and measurements of all damaged sections.

Address the moisture source first or your new soffit will rot just as quickly. Common causes include clogged gutters overflowing onto the soffit, missing or damaged drip edge allowing water to run back under the shingles, inadequate attic ventilation creating condensation, or ice dams in winter. Clean your gutters thoroughly and ensure they drain properly away from the building. In coastal Saint John, gutters should be cleaned at least twice yearly due to salt corrosion and debris accumulation from Bay of Fundy storms.

For material selection in coastal Saint John, avoid standard pine or fir lumber that will rot again within 5-10 years. Fiber cement soffit boards ($4-$7 per linear foot) are the premium choice — completely rot-proof, insect-proof, and designed for coastal environments. PVC or vinyl soffit ($2-$4 per linear foot) is more affordable and maintenance-free, though it can become brittle in extreme cold. Pressure-treated lumber ($3-$5 per linear foot) is acceptable but requires regular staining every 3-4 years in the salt air. Aluminum soffit ($3-$6 per linear foot) is lightweight and corrosion-resistant but can dent from hail or impact.

The replacement process involves carefully removing the damaged boards without disturbing the roof structure above. Use a pry bar and reciprocating saw to cut through any nails or screws holding the soffit. Work slowly — the fascia board above may be damaged and could shift if you're too aggressive. Measure each opening carefully since older garages rarely have perfectly square or consistent dimensions. Cut your new soffit boards 1/8 inch shorter than the opening to allow for expansion and easier installation.

Install proper ventilation while the soffit is open. Coastal garages need excellent ventilation to prevent moisture buildup that leads to rot, mold, and ice dams. Install soffit vents every 4-6 feet along the overhang — these allow air to enter the attic space and exit through ridge vents or gable vents. In Saint John's humid climate, inadequate ventilation is often the root cause of soffit rot, not just direct water exposure.

When to hire a professional: If the fascia boards are also rotted, if you discover rafter tail damage when removing the soffit, if the garage roof structure appears compromised, or if you're uncomfortable working on a ladder in Saint John's frequent wind. Structural repairs require proper engineering, especially in coastal areas where wind loads are higher. Also consider hiring a pro if your garage is two stories or has complex roofline details where water intrusion could affect the main structure.

Expect to spend $8-$15 per linear foot for DIY soffit replacement in Saint John, including materials and basic tools. Professional installation runs $12-$25 per linear foot depending on access difficulty and material choice. The investment is worthwhile — properly installed, ventilated soffit in appropriate materials should last 25-40 years even in Saint John's challenging coastal environment.

Need help finding a professional garage contractor for more complex soffit or roof repairs? New Brunswick Garages can match you with experienced local contractors through the New Brunswick Construction Network.