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Dolphin Pool & Spa

How to Check for Cracks and Damage After a Minnesota Winter

Monday, May 4, 2026  ·  Your Happy Dolphin Pool & Spa Team

Checking pool coping for cracks after a Minnesota winter

Images are AI generated and do not depict an actual pool or Dolphin Pool & Spa location.

Minnesota winters are not kind to pool structures. Months of freeze-thaw cycling, ground movement, ice expansion, and temperature swings that can swing 80 degrees in a single season put real stress on every part of your pool — from the shell and coping to the deck, plumbing, and equipment. Most of that stress is invisible while the pool is closed and covered.

Spring opening is your annual opportunity to do a thorough walkthrough before the water goes in and hides any problems. Catching damage early — before the pool is full and running — saves you money, prevents small issues from becoming big ones, and makes for a much smoother season. Here's what to look for and where to look for it.

1 The Pool Shell and Walls

Once the cover is off and the water level is low enough to see the walls clearly, walk the perimeter slowly and inspect the shell. What you're looking for depends on your pool type:

Pool Type What to Look For
Vinyl Liner Tears, holes, wrinkles that weren't there before, liner pulled away from the bead track, fading or brittleness around the waterline
Concrete / Gunite Cracks (hairline or structural), spalling, rough patches, staining that may indicate seepage
Fiberglass Crazing (fine surface cracks), blistering, delamination, or any areas where the surface feels soft or hollow

💡 Pro Tip: For vinyl liner pools, run your hand slowly along the walls at and just below the waterline. Small tears are easy to miss visually but you'll feel them. A liner that has become stiff or crinkly — especially around return jets and skimmers — is telling you it's nearing the end of its life.

2 Coping, Tile, and the Waterline

The coping — the cap stones or poured concrete that runs around the top edge of the pool — takes a beating from freeze-thaw cycles every single year. Walk the entire perimeter and look for:

  • Cracked or broken coping stones
  • Coping that has shifted, lifted, or separated from the pool shell
  • Missing or deteriorated mortar joints between stones
  • Cracked or popped waterline tile
  • Grout that has washed out or crumbled
  • Any section where water could get behind the coping and refreeze next winter

⚠️ Don't ignore coping cracks. Water that gets into a crack in your coping will freeze, expand, and make the crack significantly larger next winter. A small repair now is far cheaper than replacing sections of coping after another season of freeze-thaw damage.

3 The Pool Deck

Concrete and paver decks shift every winter as the ground freezes and thaws. Most of it is cosmetic — but some of it is a trip hazard or a drainage problem waiting to happen. Look for:

  • Cracks wider than a hairline — especially if they run toward the pool
  • Sections that have heaved, settled, or are no longer level
  • Paver stones that have shifted, tipped, or have wide gaps between them
  • Expansion joint material that has dried out, crumbled, or pulled away
  • Areas where water pools instead of draining away from the pool
  • Spalling or surface deterioration from road salt tracked in from driveways

💡 Pro Tip: Walk the deck in bare feet after a dry day. You'll feel lifted edges, soft spots, and uneven sections far more reliably than you'll see them. Any trip hazard near the pool edge is a safety issue that needs to be addressed before anyone is running around the deck this summer.

4 Skimmers, Returns, and Fittings

Plastic fittings that are set into the pool wall are vulnerable to freeze damage — especially if the pool wasn't winterized correctly or if water levels were higher than recommended going into winter. Check each one carefully:

  • Skimmer body — look for cracks in the plastic housing, especially around the throat and faceplate
  • Skimmer lid and basket — replace if cracked or warped
  • Return jet fittings — check for cracks and confirm the eyeball fitting turns freely
  • Main drain cover — inspect for cracks and confirm it is secure and compliant
  • Gaskets and faceplates — replace any that are brittle, cracked, or no longer sealing properly
  • Light niches — check for cracking around the lens and housing

5 Underground Plumbing — The Leak Test

You can't see underground plumbing, but you can test it. Before you fill the pool, plug the return lines and skimmer lines at the equipment pad and pressurize each line with a simple pressure test. A line that won't hold pressure has a crack or separation somewhere underground — and you want to know that before the pool is full of water and you're watching your level drop an inch a day trying to figure out why.

⚠️ Losing water after opening? Don't assume it's evaporation. Minnesota pools lose roughly ¼ inch per day to evaporation in summer. Anything more than that — especially if it happens consistently regardless of temperature or wind — points to a leak. Give us a call and we can help you track it down before it becomes a much bigger problem.

6 Equipment Pad and Mechanical Components

Walk your equipment pad and give everything a visual once-over before you fire anything up. Look for:

  • PVC pipe fittings or unions that have cracked or separated over winter
  • Pump housing cracks — especially on older single-speed pumps
  • Heater connections and gas fittings — look for corrosion or physical damage
  • Filter tank for cracks, UV damage, or seam separation
  • Valves and unions — turn each one by hand before startup to confirm it moves freely
  • Electrical conduit and wiring — look for rodent damage over the winter months

💡 Reminder: Never run your pump dry. Before you start the system for the first time each spring, confirm all valves are open and water is flowing freely. Running a pump without water even briefly can damage the mechanical seal and void the warranty.

7 When to Call a Pro

Some things you can address yourself — a cracked skimmer lid, a worn gasket, a shifted paver. Others are worth a professional set of eyes before you proceed:

  • Any crack in the pool shell wider than a hairline
  • A skimmer body that is cracked through or pulling away from the wall
  • Plumbing lines that fail a pressure test
  • Water loss that continues after opening despite no visible damage
  • Coping or deck sections that have shifted significantly toward the pool
  • Any electrical damage or wiring concerns near the water

Dolphin Pool & Spa has been diagnosing and repairing Twin Cities pools since 1988. If you find something during your spring walkthrough that doesn't look right, give us a call — we'd rather help you catch it early than see you dealing with a bigger problem mid-summer.

Found Something That Doesn't Look Right?

We're Here to Help.

Don't wait on damage you find at opening — small problems don't stay small for long. Give us a call and we'll walk you through your options. We're here Mon–Thurs 8–5, Fri 8–6, and Sat 8–4.

Call Us Now — 763-542-9000
Dolphin Pool & Spa

Your Happy Dolphin Pool & Spa Team

3405 Hwy 169 N, Plymouth MN  ·  763-542-9000  ·  dolphinpool-spa.com