Closing the Lake House for Winter: A Pipe-First Checklist

The most expensive thing you can find when you open a lake house in April is a split pipe. Closing up is mostly about water: where it sits, where it can freeze, and what happens when it expands. This checklist puts the water side first, then everything else.

Which pipes freeze first

The American Red Cross lists the pipes most exposed to severe cold as outdoor hose bibs, swimming pool supply lines and water sprinkler lines, followed by supply pipes in unheated spaces such as basements, crawl spaces, attics, garages and kitchen cabinets, and pipes that run along poorly insulated exterior walls (American Red Cross, Preventing and Thawing Frozen Pipes). At most lake houses that list describes half the plumbing.

Step 1: Outdoor hoses and bibs

Disconnect and store every hose. Close the indoor valve that feeds each outdoor bib, then open the outdoor bib and leave it open. The Red Cross explains why: an open outside valve lets any water left in the pipe expand without breaking it (same source).

Step 2: Sprinkler, pool and other outdoor lines

Drain irrigation and pool supply lines following the manufacturer's or installer's directions. Do not pour antifreeze into these lines unless those directions call for it; the Red Cross notes antifreeze is harmful to people, pets, wildlife and landscaping (same source).

Step 3: Decide: heat on, or fully drained

There are two ways to leave a lake house for winter.

1. Heat stays on. If the house will be heated while you are away, the Red Cross recommends a thermostat setting no lower than 55 F (same source). Add insulation in attics, basements and crawl spaces and insulate hot and cold lines in unheated areas; pipe sleeves or UL-listed heat tape are the options it names (same source).
2. Fully drained. If the heat goes off, the whole system has to be emptied, including the water heater, traps and any pump or pressure tank. Because systems differ (well vs municipal, pump type, slope of the lines), this is the job most owners hand to a plumber the first year and then repeat themselves from the plumber's notes.

Step 4: The quick-thaw plan for whoever checks on the house

If someone checks the house during a cold snap and a faucet only trickles, the Red Cross says to suspect a frozen pipe, keep the faucet open, and apply gentle heat such as a heating pad, a hair dryer or towels soaked in hot water, never an open flame, blowtorch, kerosene or propane heater (same source). If the frozen section cannot be found or reached, call a licensed plumber. Leave that note on the counter.