What the Corps says about materials
| Part | Rule | SMP section |
|---|---|---|
| Decking and walkways | Treaded metal, lumber treated with environmentally suitable chemicals, or skid-resistant marine products | 15.3.4 |
| Coverings | Carpet and similar coverings banned; existing carpet has to come off | 15.3.4 |
| Floats | Marine floats, 8-year warranty, fire resistant; no drums | 15.3.2 |
| Paint and stain | Optional; if used, dark browns, black or dark greens only | 15.3.8 |
| Bare wood | May be left to weather naturally | 15.3.8 |
| Roofs | Wood and shingle, or metal; pitch no steeper than 3 in 12 | 15.3.5 |
| Shore steps | No arsenic-treated wood, no landscape timbers | 15.3.11 |
Source: 2004 Shoreline Management Plan.
Decking materials compared
| Material | Installed dock, per sq ft | Lifespan | Upkeep |
|---|---|---|---|
| Pressure-treated pine | $20–70 | Up to 20+ years | Preservative and stain every year |
| Cedar | $20–60 | 25+ years | Waterproof every year |
| Plastic / composite-type | $15–60 | 30+ years | Regular washing |
| Vinyl | $20–70 | 25+ years | Washing |
| Aluminum | $25–75 | 30–50 years | Little |
| Hardwood | $30–90 | Up to 75 years (some species) | Oil or let it grey |
National figures for a dock built in each material, labour included, from Fixr (Jan 2025). Lanier docks are large, covered and deep-water anchored, so whole-dock prices here run higher; our dock cost guide has Lanier planning ranges, including composite or PVC decking as a $4,000–12,000 upgrade (our estimate).
Steel or aluminum frames
Both are on the lake: Lanier dealers' used lists include steel docks and aluminum ones (Marine Specialties). Steel is strong, but its coating has to be kept up against rust. Aluminum resists corrosion, and Fixr gives it a 30–50 year life (Fixr). Whatever the frame, a railed roof deck adds load, so ask what the structure is designed to carry. The plan notes that metal anchor posts add grounding if the wiring ever fails (SMP §15.3.9).
Floats
Floats carry everything, and they fail quietly. The Corps wants marine floats warranted for at least 8 years against sinking, waterlogging, cracking and shedding beads, and floats within 40 ft of a fuel line must be fully impervious to water and fuel (SMP §15.3.2). Loose foam from old floats is a large part of what volunteers pull from the lake each year (LLA). Fixr puts replacing a single float at $150–200 (Fixr). Refloating is often the best-value repair on an older dock; see repair or replace.
What to ask before you choose
- Is the decking skid resistant when wet, and how hot does it get in July sun on bare feet?
- What float brand, and what does its warranty cover?
- Is the frame steel or aluminum, and what coating or alloy?
- Which parts need yearly care, and what does that cost?
- If painted, is the colour on the Corps' list?
Common questions
Can I put composite decking on my Lake Lanier dock?
Yes. The plan allows marine products with skid-resistant surfaces alongside treaded metal and treated lumber (SMP §15.3.4). A same-size redeck usually doesn't change your permit, but check with your ranger.
Is carpet allowed on a Lanier dock?
No. The Corps bans carpet and similar coverings because they hide rot, promote decay and get slippery, and existing carpet must be removed (SMP §15.3.4).
What colours can I paint my dock?
You don't have to paint. If you do, dark browns, black and dark greens that blend in are required; bright colours aren't allowed (SMP §15.3.8).
How long does an aluminum dock last?
Fixr gives aluminum docks a 30–50 year lifespan, against up to about 20 years for maintained pressure-treated wood (Fixr). Floats and decking may need replacing sooner.
Sources & further reading
- Lake Sidney Lanier Shoreline Management Plan (2004), hosted by the Lake Lanier Association. §12, §15.1–15.3, §18
- Fixr: cost to build a dock (updated Jan 2025). Cost and lifespan by material, float replacement
- Marine Specialties: used docks and lifts. Steel and aluminum docks on Lanier
- Lake Lanier Association: shoreline sweep. Foam debris
Editorial note: General planning information, not engineering or legal advice. Prices are estimates; confirm current rules with your local officials and a qualified pro.