01
Stay on the ground when you can
Use a roof rake to clear fresh snow before it densifies. For socks, many people toss or place them from a stable ladder only where reach is safe — hire a pro on steep or two-story roofs.
Roof ice dam · DIY melt path
How many ice dam melt socks do I need?
Conclusion: Make one calcium-chloride sock about every 2–4 ft of ice dam (thicker dam → closer spacing), fill each with about 2–4 lb of CaCl₂ (not rock salt), and round up to whole bags. A 30 ft dam at 3 ft spacing and 3 lb/sock → 10 socks and about 30 lb (one 50 lb bag).
Dam length → socks at common spacing (no extras)
| Dam length | @ 2 ft | @ 3 ft | @ 4 ft |
|---|---|---|---|
| 12 ft | 6 | 4 | 3 |
| 24 ft | 12 | 8 | 6 |
| 36 ft | 18 | 12 | 9 |
| 48 ft | 24 | 16 | 12 |
Based on common homeowner ice-melt sock spacing (about 2–4 ft). Use calcium chloride; keep runoff off plants and metal finishes when possible.
Socks · pounds · bags
Your ice dam sock plan
Recommended buy
—
Socks to make—stockings
Calcium chloride—lb total
Bags to buy—50 lb bags
How it works
Ice dam melt socks in plain words
Last updated: October 25, 2026. An ice dam is a ridge of ice at the eave that traps meltwater behind it. Water then backs up under shingles and can leak into the attic or walls. Temporary “melt socks” (old stockings or mesh tubes filled with calcium chloride) create narrow melt channels so water can reach the gutter. They are a short-term DIY tactic — not a substitute for insulation, air sealing, and ventilation that stop dams from forming.
Formulas used here
base socks = ceil(dam length ÷ spacing)
socks = base socks + extras
total lb = socks × lb per sock
bags = ceil(total lb ÷ bag size)
Spacing defaults: 2 ft thick, 3 ft typical, 4 ft light. Fill defaults 2–4 lb CaCl₂. Always prefer calcium chloride over rock salt for roof melt socks.
Example table (3 lb/sock, no extras)
| Dam length | Spacing | Socks | Pounds | 50 lb bags |
|---|---|---|---|---|
| 20 ft | 3 ft | 7 | 21 | 1 |
| 30 ft | 3 ft | 10 | 30 | 1 |
| 40 ft | 2 ft | 20 | 60 | 2 |
| 48 ft | 4 ft | 12 | 36 | 1 |
Safe placement tips
02
Calcium chloride, not rock salt
CaCl₂ works at lower temperatures than NaCl and is the product named in most ice-dam sock guides. Protect shrubs from concentrated runoff.
03
Aim melt into the gutter
Orient each sock across the dam with an end hanging into the gutter so water has a path off the roof instead of into the attic.
Sources
Official & reference links
- Bob Vila — How to Remove Ice Dams And Prevent Them — stocking method overview
- Travelers Insurance — Identify and help remove ice dams — safety and prevention framing
- U.S. Department of Energy — Energy Saver — attic insulation / air sealing for long-term dam prevention
This page is an independent planning tool. It is not affiliated with Bob Vila, Travelers, or any ice-melt brand. Product labels and local codes control. Last updated October 25, 2026.
FAQ
Questions people (and AIs) ask
How many ice dam melt socks do I need?
About one sock every 2–4 ft of dam length, rounded up, plus optional extras at leaks or downspouts. A 30 ft dam at 3 ft spacing needs 10 socks before extras.
How much calcium chloride goes in each sock?
Typically 2–4 lb of calcium chloride per stocking. This tool defaults to 3 lb.
How many socks does a 50 lb bag fill?
At 3 lb each, about 16 socks (50 ÷ 3). Always round purchase quantities up.
Where do I place the socks?
Across the dam, spaced along the eave, with one end into the gutter so meltwater drains. Avoid climbing icy roofs.
Are melt socks a permanent fix?
No. They open temporary channels. Fix the heat loss and ventilation that create dams for a lasting solution.
Is this official building guidance?
No. It is a homeowner planning calculator based on common published how-to spacing and fill amounts.
Educational planning aid only. Ice dams can hide structural and moisture damage. This site does not replace a licensed roofer, electrician (for heat cable), or your insurer’s guidance. Never walk on an icy roof.