You mounted the hammock, your cat jumped in once, and an hour later it slid down the glass. Frustrating — but almost always fixable. Suction cups fail for a handful of predictable reasons, and every one of them has a solution.
1. Clean the glass properly (this fixes most cases)
Dust and invisible grease films are the number one cause of failed suction. Spray the mounting area with window cleaner, wipe it with a lint-free cloth, and — this part matters — let it air dry completely. A damp surface traps a micro-layer of water that breaks the seal as it evaporates.
2. Clean the cups too
The rubber picks up dust from packaging and from your hands. Wash each cup with warm water and a drop of dish soap, rinse and dry fully. Never use oils or lubricants — they degrade the rubber.
3. Mind the temperature
Suction cups grip best when installed between roughly 65°F and 85°F (18–29°C). In cold weather the rubber stiffens and can't conform to the glass. If your window is cold, warm the cups in your hands or in warm water for a minute before mounting.
4. Press out all the air
Place the cup flat, then press firmly from the center outward. If your hammock has locking levers, press first and lock second — not the other way around.
5. Do the twist test before your cat gets in
Wait 24 hours after mounting, then gently rotate each cup about 45 degrees. If it resists, the seal is solid. If it slips, remount. Only then let your cat use it — supervised the first few times.
6. Check your glass type
Suction needs smooth, non-textured glass. Frosted, tinted-film, or heavily coated windows can prevent a proper seal. If that's your situation, a window sill perch or hook-mounted perch is the better choice — no suction cups involved.
7. Re-seat every few weeks
Suction naturally weakens over time as tiny amounts of air seep in. Pop the cups off, wipe them and the glass, and remount monthly. Thirty seconds of maintenance prevents surprises.
How much weight should a window hammock hold?
Look for a metal frame rather than plastic, and a stated capacity well above your cat's weight. Our Premium Cat Window Hammock uses a sturdy metal frame with heavy-duty cups and supports cats up to 44 lbs — comfortable margin even for a Maine Coon.
When a perch beats a hammock
If your window has a deep sill or a frame slot, a hook-mounted or sill-resting perch skips the suction question entirely. Cats don't care how it's attached — they care that it's warm, stable, and has a view. Browse the full range of cat window perches to compare mounting styles.
Still slipping after all seven fixes? Message us — we'll help you work out whether it's the glass, the cups, or the mount.