Roof leak / soft deck

Map before you coat. Walk seams, screw heads, vent flanges, and antenna mounts in daylight. Lap sealant that is cracked, chalked, or pulled away is a classic path. Interior stains often show up downhill from the real hole — a wet corner over the bed can start at a front cap joint or an AC shroud two bays forward. EPDM and TPO membranes fail differently than sealant alone; coating over dirt, mildew, or an unsound deck locks moisture in. Do not buy five gallons of coating until you know where water is getting in.

Symptoms

• Ceiling stain that grows after rain (or only after wind-driven rain)
• Musty smell in a closet or over a slide with no obvious drip yet
• Soft or spongy deck near a vent, AC, skylight, or ladder mount
• Lap sealant cracked, alligatoring, or lifted at screw heads
• Leak only while driving / only at highway speeds
• AC condensate vs true roof intrusion confusion (wet near the AC chase)
• Aftermarket dish / antenna / Starlink plate with a tired boot or open screw ring

Quick path (owner-safe)

1. Map interior stains to the nearest roof penetration uphill. Mark the ceiling with tape and take photos on a wet day and a dry day.
2. Inspect lap sealant, self-leveling caulk, and membrane seams. Look for alligatoring, voids, and lifted edges — especially on EPDM lap lines and around older butyl.
3. Press-test soft spots carefully with a flat hand — don’t punch through a wet deck. Note spongy feel vs solid.
4. Check AC shroud screws, gasket condition, vent flanges (bathroom, range, fridge), ladder mounts, and antenna / dish plates.
5. Differentiate AC condensate drain paths from roof entry — a wet chase under the AC is not always a membrane hole.
6. Document with photos before a mobile tech arrives; note recent roof work, coating, or wireless mounts.

Symptom forks

• Stain after rain, dry roof walk — slow seam leak or wind-driven rain at a flange; re-check after the next storm with chalk/tape markers.
• Soft deck near a vent — flange seal failure; stop walking that area until inspected.
• Leak only while driving — often front cap / radius joints or a poorly sealed aftermarket mount seeing wind pressure.
• Musty smell, no visible stain yet — early intrusion; thermal moisture mapping beats ripping headliner blind.
• Wet only under the AC — condensate management vs gasket failure; don’t coat the whole roof for a drain hose.
• New wireless mount, old stain pattern — re-inspect the boot and screw ring; clear-sky mounts still need a weatherproof seal (Starlink install capability — not a “Starlink Certified” claim).

Don’t skip (sealants, vents, AC gasket, EPDM)

• Front/rear cap joints and ladder mounts — high-motion, high-miss areas.
• AC shroud screws and gasket condition — retorqued shrouds without resealing are a classic DIY miss.
• Self-leveling vs non-leveling sealant used in the wrong place (vertical wall vs flat roof puddle).
• EPDM chalking, open laps, and failed tape repairs under a cosmetic coating.
• Skylight and MaxxFan flanges; bathroom vent caulk lines; fridge roof jack.
• Satellite / Starlink / antenna plates — seal integrity after any roof work.

Owner checklist

• Roof membrane type if known (EPDM / TPO / fiberglass) and any prior coating brand/year.
• Photos of stains inside, soft spots, and every penetration you can safely reach.
• AC brand/model and whether the shroud was recently removed.
• Recent aftermarket mounts (dish, antenna, Starlink, weBoost) and who sealed them.
• Coach year/make/model and parking location for a trip quote.

When to stop DIY

• Soft deck you can flex with light pressure — structural risk; Prefer Text.
• You are about to coat over dirt, mildew, or an unsound membrane.
• Active drip onto electrical, into a wall cavity, or onto 12V/120V gear — stop and dry-isolate; Prefer Text.
• Working at height in wind without fall awareness — wait for a mobile tech with the right setup.
• Delaminated walls, swollen cabinetry, or ceiling panels that sag — beyond a tube of Dicor.

What UMRT does on a roof call

Diagnostics-first leak finding (thermal imaging where needed), seam and penetration inspection, and honest scope: patch vs section vs full coat. We do not sell a coating as a magic fix over a soft deck, and we will say when structural or electrical-wet conditions mean stop DIY and plan a real repair. Prefer Text to book — trip fee quoted upfront.

Trip $75 / 30 mi then $1.50/mi · labor ~$150/hr (1 hr min / 30-min) · diagnostic $175 applied if you proceed. Corridor MT · WY · ID · WA.

Related guides & siblings

Deep dive: Roof leak troubleshooting · Roof coating guide · Roof service. Wireless mounts: Starlink / weBoost / Peplink (installs with sealed penetrations — no invented Starlink cert). Related: freeze vs intrusion lookalikes. Hub: Troubleshoot.

Prefer Text — (616) 606-5277. Trip $75/30 mi then $1.50/mi · labor ~$150/hr (1 hr min / 30-min) · diagnostic $175 applied · winterize $175 · trip-prep $225. Credentials: Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified.