You repair a leak, and after a couple of months, it reappears at the same spot. That typically indicates the fault lies not in the shingle you had to replace, but in the manner in which the roof was initially installed. If you want to go here and learn what bad installation looks like, this list covers the mistakes we see most often.
Mislocated Nails
Each shingle has a designated nailing area. If the nails are located high on the shingle, then they are located where the doubled layer is not present, and the wind can easily move the shingle. Nails that have not been driven properly will fail to puncture through the roof. When nails poke out of the roof surface, they exert pressure on the succeeding shingle and make a hole in it.
Missing Underlayment
The layer under your shingles is there for the times when water gets past the top. Some crews skip it in tricky areas or overlap it the wrong way. Valleys, eaves, and spots around vents need extra protection. When that is missing, the same few places keep leaking.
Flashing Held Together With Caulk
The chimneys, skylights, and walls require metal flashings to be placed under the shingles. Caulk itself doesn’t last very long. It dries up and cracks after several years. If the flashing is not long enough or has not been cut out of the brick, then water gets behind the flashing.
Messy Valleys and Ridges
Valleys carry more roof water than anything else. If shingles are cut crooked or the cut edge faces the flow, water creeps sideways under them. At the ridge, loose caps and poorly fitted vents let rain blow in during storms.
Poor Airflow in the Attic
Some installers never check ventilation. A hot, damp attic wears out the roof from below and leaves moisture on the underside of the deck. It looks like a leak, but the roof is not the cause. Insulation stuffed against the soffit vents is a common reason.
Rotted Wood Left Under New Shingles
When the old roof comes off, any soft or damaged plywood should be replaced. Covering it up saves a few hours and costs the homeowner later. Nails will not hold in weak wood, and low spots let water sit.
Signs Your Roof Was Installed Badly
- Shingles that are lifting, curling, or out of line
- Nail heads showing or small bumps on the surface
- Ceiling stains that keep coming back in one area
- Thick sealant around vents and chimneys
Conclusion
A good repair finds the cause behind the leak. That might mean redoing flashing, resetting a section of shingles, or replacing bad decking. If you would like to go here for more on how we handle residential roofing in Cherry Hill, our roofing page explains our process. In case your roof continues leaking despite all the repairs, schedule an inspection with RGB Construction Services, as we will examine the entire roof and determine why the repair failed and what should be done about it.