Air is likely leaking at the moving window sash
The draft follows the joint where the window opens or slides. Worn, missing, or compressed weatherstripping is a more likely cause than a gap in the wall assembly.
Why this result fits
- The strongest airflow is at a movable sash joint.
- The glass and surrounding trim appear intact.
- Operable windows commonly rely on weatherstripping that can wear with use.
What to do now
Close and latch the window normally
Clear the track of loose debris, then close and latch the window without forcing it. A latch may draw the sash against its existing seal.
Document the leak path
On a windy day, move the back of your hand slowly along the sash joint and note the strongest location. Do not use a flame, incense, or smoke.
Ask before adding a seal
Send maintenance a photo and request repair. If the lease permits a temporary product, use only removable weatherstripping sized for a moving joint.
Stop and escalate if
- The window is loose, cracked, will not lock, or cannot open normally.
- Water enters or nearby material is wet, stained, soft, or deteriorating.
- Any temporary material would interfere with ventilation or emergency escape.
What not to do
- Do not permanently caulk a joint that must move.
- Do not force a damaged latch or sash.
- Do not cover active moisture or prevent the window from opening.
Optional products
Tools that fit this result
You may not need to buy anything. These are product types with distinct roles, not a list of near-duplicate items.
Removable window weatherstripping
A lease-approved temporary seal for an intact moving sash joint.
What to look for
- Removable and sized for the measured gap
- Compatible with the frame finish
- Allows the sash and lock to operate normally
Limits
- Test adhesive on a hidden spot first
- Remove it if the window binds or will not latch
- Not a repair for damage, water entry, or a frame-to-wall gap
Paid link. As an Amazon Associate I earn from qualifying purchases. A purchase may earn Apartmentwise a commission at no added cost to you.
Frost King R338H Self-Stick Rubber Foam Weatherseal
Amazon ASIN: B000BQWWF4
Check price on Amazon (paid link; opens in a new tab)Paid link
Temporary interior window insulation kit
A seasonal option that can reduce the effect of an intact but leaky window when the lease permits it.
What to look for
- Interior removable installation
- Compatible with the frame finish
- Clear removal instructions
Limits
- Never install where it blocks required ventilation or emergency escape
- Do not trap active moisture behind film
- May leave adhesive residue or affect delicate finishes
Paid link. As an Amazon Associate I earn from qualifying purchases. A purchase may earn Apartmentwise a commission at no added cost to you.
3M Indoor Window Insulator Kit for Five Windows
Amazon ASIN: B00002NCJI
Check price on Amazon (paid link; opens in a new tab)Paid link
Message you can send to maintenance
I feel a draft along the moving sash at [location]. The window is [able/unable] to close and lock normally, and I observed [no water or damage / describe damage]. Please inspect the weatherstripping and window operation before I add any temporary seal.
Help prevent a repeat
- Keep tracks free of loose debris without dismantling the window.
- Report failed locks, worsening gaps, and water entry promptly.
If this does not match
Sources and review date
- Renters — U.S. Department of Energy
- Window Types and Technologies — U.S. Department of Energy
Content last reviewed: under the Apartmentwise methodology.