The short answer
Check the Seal and Caulk
The most common reason for a bottom leak is failed caulk or sealant around the window frame. Over time, sun and temperature swings crack the seal, letting rain seep in. Look for gaps, peeling, or brittle sections along the bottom edge and corners.
If you find damage, remove the old caulk and apply a fresh bead of exterior-grade sealant. Make sure the surface is dry before you apply it. This is a straightforward fix that can stop many leaks, but it only works if the rest of the window is sound.
Inspect the Weep Holes
Weep holes are small slots at the bottom of the window frame that let condensation and rain drain out. If they are clogged with dirt, paint, or debris, water backs up and spills over the sill. Clear them with a small wire or compressed air.
Also check that the weep holes are not blocked by the window screen or a poorly fitted sill. If you cannot clear them easily, a water damage inspection can help identify why water is pooling and where it is entering your wall.
- Look for small slots or holes along the bottom frame
- Use a wire or air duster to clear debris
- Ensure the sill slopes away from the window
- Check if the weep holes are covered by paint
- Test by pouring a cup of water on the sill
Look at the Flashing and Sill Pan
Flashing is a metal or plastic strip that directs water away from the window joint. If it is missing, bent, or installed incorrectly, water can run behind the siding and down to the bottom of the window. The sill pan, which sits under the window, should also be sloped outward.
You can test the slope by placing a level on the sill. If it tilts toward the interior, water will naturally flow inside. Fixing this may require removing the window and reinstalling it, so consider calling a professional for a proper evaluation.
Consider the Window Age and Installation
If your window is old or was installed without proper weatherproofing, leaks can develop even with no visible cracks. Nails that missed the frame, missing shims, or a poorly fitted unit can all create paths for water. In these cases, a simple caulk job will not hold.
A window replacement might be the right option if the frame is rotted or the leak is severe. Before you decide, have a water damage inspection done to see how far moisture has traveled into the wall. That will help you understand the full scope of the problem.
Address Water Damage Right Away
Once water enters your wall, it can soak insulation, rot wood, and encourage mold growth. If you notice staining, soft drywall, or a musty smell near the window, act quickly. Drying the area and removing wet materials is important to prevent structural issues.
For significant water intrusion, you may need emergency water extraction and structural drying. These services help remove moisture from hidden cavities. Policies vary, and your insurer decides what is covered. Check your policy to see what your insurance covers, and ask a qualified attorney if you have a dispute.
- Dry wet surfaces with towels or fans
- Remove soaked carpets or padding
- Cut out wet drywall if it is sagging
- Run a dehumidifier to lower humidity
- Call a mold professional if you see growth
Talk to someone now
Phones are answered 24/7 for Orem and nearby communities.
Call Now (801) 876-1119Frequently asked questions
Can I fix a leaking window myself?
Yes, if the cause is simple caulk failure or clogged weep holes. Clean the holes, replace the caulk, and test with water. If the leak persists or you see interior damage, call a pro to avoid making it worse.
How do I know if the leak is from rain or condensation?
Rain leaks happen during or right after a storm, and water appears at the bottom sill. Condensation forms on the glass and runs down, but it usually leaves water on the sill only. Check the window frame for wetness after a dry night to tell the difference.
Should I replace the window or just repair the seal?
If the frame is solid and the leak is from a seal, repair is enough. If the wood is soft, the glass is foggy, or the leak returns after resealing, replacement is more cost-effective. A professional inspection can guide you.