How to Fix a Leaking Roof

Find the leak source by checking for water stains and damaged materials, then repair with appropriate sealant, patches, or replacement shingles depending on the damage type.

1. Trace Water to Its Origin. Start inside your home by looking for water stains, discoloration, or wet spots on ceilings and walls. Follow the water trail upward since water can travel along rafters before dripping. Mark the general area with chalk or tape. Remember that the actual roof damage is usually higher up the slope from where you see interior damage.
2. Scout Exterior Damage Zones. Wait for dry weather and carefully climb onto your roof using a sturdy ladder with someone spotting you. Look for obvious damage like missing or cracked shingles, exposed nail heads, damaged flashing around chimneys or vents, or cracked caulking. Check the area above where you found interior damage. Take photos to document what needs repair.
3. Swap Out Bad Shingles. For missing or severely damaged shingles, carefully lift the shingle above the damaged area and remove the nails holding the bad shingle. Slide out the old shingle and slide a new one into place. Nail it down with roofing nails, then apply a small dab of roofing cement over each nail head. Press the upper shingle back down to cover the nails.
4. Seal Small Fractures Fast. For small cracks in shingles or minor holes, clean the area of debris and apply roofing cement or elastomeric sealant generously over the damage. Spread it beyond the edges of the crack by at least an inch on all sides. For larger holes, cut a piece of metal flashing or roofing membrane slightly larger than the hole, embed it in sealant, then cover with more sealant.
5. Seal Vulnerable Penetrations. Check flashing around chimneys, vents, and roof valleys for gaps or corrosion. Remove old caulk or sealant completely. Apply new roofing cement or specialized flashing sealant to fill gaps and create a watertight seal. For severely damaged flashing, you may need to replace the entire section by carefully removing the old flashing and installing new material.
6. Tarp It Until Conditions Allow. For temporary repairs during bad weather, cut a piece of tarp or roofing membrane larger than the damaged area. Secure it with roofing cement around all edges and nail down with roofing nails every few inches. This is only a temporary fix until proper repairs can be made in dry conditions.
7. Verify the Fix Works. After repairs dry completely, spray the area gently with a garden hose to test for leaks. Start low on the roof and work your way up to the repaired area. Have someone inside check for any new water penetration. Monitor the area during the next few rainstorms to ensure the repair is holding.