Roof Deck, Fascia and Soffit Rot: What It Costs to Fix
Rot on a Fort Collins roof almost always starts at the edge. Not in the middle of a slope, where the shingles are, but along the eaves where the decking, the fascia board behind the gutter, and the soffit under it meet. It's dry here, which slows rot compared to a humid climate, but the edge of the roof gets wet in a way the rest of it doesn't: ice dams in March, overflowing gutters in a July cloudburst, and meltwater running behind a gutter that hail knocked out of line years ago. Here's what it looks like, why it spreads, and what the repair costs.
The three parts, and what each does
The roof deck is the plywood or OSB the shingles are nailed to. On Old Town houses it may be 1x6 skip sheathing with plywood over it; on anything after the 1970s it's 1/2-inch plywood or 7/16 OSB. The first sheet at the eave is the one that rots.
The fascia is the vertical board at the edge of the roof that the gutter hangs from. Usually a 1x6 or 1x8 of pine or cedar, sometimes wrapped in aluminum.
The soffit is the horizontal panel under the overhang. Wood, hardboard, or vented aluminum or vinyl. It's where the attic's intake vents are, which is why soffit damage matters beyond looks.
How the water gets in
Hail-dented gutters. A gutter that took hail years ago and was never replaced with the roof is often pushed out of pitch or dented so it holds water at the back edge, against the fascia. Every rain and every melt wets the fascia. This is the most common cause we see in Fort Collins, because so many roofs were replaced on insurance claims that paid for shingles and not the gutters.
Ice dams. Meltwater backs up behind ice at the eave and soaks the first course of decking from above. If there's no ice-and-water shield, it gets into the plywood and the top of the fascia. The attic insulation post explains why that happens here.
Missing or short drip edge. Drip edge is the metal strip that carries water off the deck and into the gutter. A lot of 1970s–90s houses don't have it, or have it installed under the underlayment where it does nothing. Without it, water wicks back under the shingle edge and runs down the fascia.
Overflowing gutters. Cottonwood leaves in October pack a gutter solid, and the next storm sends water over the back edge.
Clogged soffit vents plus a bath fan. Moisture in the attic condenses at the coldest spot — the eave — and rots the soffit from inside.
What it looks like from the ground
- Paint peeling or bubbling on the fascia behind the gutter
- A gutter that has pulled away or sags at one end, because the fascia can't hold the hangers
- Dark stains on the soffit, or soffit panels sagging
- A soft spot in the shingle edge when you press it from a ladder
- Wasps or birds getting into the soffit — they find the rotted opening first
How far it spreads
Rot in the first sheet of decking usually stays in that sheet if it's caught within a year or two. Left longer, it works into the rafter tails — the ends of the rafters that carry the overhang — and at that point the repair goes from carpentry to framing. A fascia board rotted through means the gutter has been unsupported for a while, which means more overflow, which means more rot. It compounds.
What it costs
| Repair | Typical Fort Collins price |
|---|---|
| Replace rotted decking | $90 – $150 per 4x8 sheet |
| Replace fascia board | $12 – $25 per linear foot |
| Replace wood soffit panel | $15 – $30 per linear foot |
| Aluminum fascia wrap | $8 – $15 per linear foot |
| Add drip edge with shingles re-laid at the eave | $6 – $12 per linear foot |
| Sister or replace a rafter tail | $150 – $400 each |
| Re-hang or replace a gutter run | $9 – $16 per foot for seamless aluminum |
A typical job — one rotted sheet, 12 feet of fascia, a section of soffit, drip edge, and the gutter re-hung — runs $900–$2,200. Rafter tails add to that. The roof repair page covers the eave work as part of a leak repair; a full replacement always includes new drip edge and a decking allowance, which is why the eaves are the cheapest thing to fix during a re-roof.
Doing it right
The fix has to break the cycle, not just replace the wood. That means: new decking with ice-and-water shield over it at the eave, drip edge installed over the membrane and under the underlayment, new fascia primed on all six sides, vented soffit so the attic has intake, and a gutter that's pitched to the downspout and hung on the new fascia with hidden hangers into solid wood. Replacing the fascia and hanging the old dented gutter back on it is a repair you'll be doing again.
When it's not the roof
If the soffit is stained but the fascia and decking are sound, look in the attic for a bath fan venting into the eave, or a soffit vent buried in insulation. That's a ventilation fix, not a rot repair, and it's cheaper. And if the decking is rotted along an eave that faces north and gets ice every winter, plan the insulation and ventilation work at the same time, or the new plywood will be wet again by the third March.
Need roof work in Fort Collins?
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