Valley Leak and Failed Spot Repair
A 25-year-old clay tile roof on a 4/12 slope has a leak above a bedroom. The roof has one layer of 30-lb felt under the tile; several field tiles are cracked and two are missing after a storm. A previous contractor repaired the area by sliding new tiles under the existing ones and sealing the joints with polyurethane caulk, but the leak continues. The valley is open metal, and the metal is rusted through in two spots. The homeowner wants to replace only the broken tiles and recaulk the valley. The attic shows water staining along a rafter bay, and the deck near the valley feels soft. The tile is no longer manufactured, and the homeowner is worried about matching the existing color.
1. Why did the previous repair fail, and is another spot repair appropriate?
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The previous repair treated a flashing and underlayment problem with caulk. Caulk at tile joints is not a water barrier, and sliding new tiles under old ones does not restore the underlayment or valley metal. The rusted-through open valley is a direct leak path; water can run through the rust holes and under the tile. The soft deck and attic staining suggest long-term moisture, likely deteriorated felt and sheathing. A spot repair of broken tiles only would leave the valley and underlayment defects in place, so the leak would continue. The appropriate step is to open the valley area, remove tiles several feet each side, inspect the deck and underlayment, and repair the valley and any rotted deck. If the underlayment is generally deteriorated, a larger restoration or replacement should be discussed. Matching tile color is secondary to watertightness.
2. Outline a repair sequence and what you would tell the homeowner.
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Install temporary dry-in if rain is expected. Remove tiles on both sides of the valley, at least 3 ft or to the next sound underlayment, and remove the rusted valley metal. Replace soft or delaminated deck panels and re-nail. Install new valley lining and underlayment per the manufacturer, with proper laps and corrosion-resistant metal. Reinstall sound existing tiles and new matching tiles, keeping exposure and headlap; if an exact match is unavailable, use a close match and place salvaged tiles in the prominent field. Seal only where the manufacturer allows; do not rely on caulk. Water-test the repair. Tell the homeowner: the broken tiles were a symptom; the valley and underlayment caused the leak. Provide photos, a written scope, and a recommendation for a full roof evaluation if more soft deck or widespread felt failure is found. Do not promise a permanent fix from a tile-only repair.