Why is water pooling on my flat garage roof?

Water pooling on a flat roof is a common problem that needs attention! Here are the main culprits:

Poor Drainage or Slope Issues Flat roofs should have a slight slope (at least 1/4" per 12 feet) to direct water toward drain areas. Over time, the roof deck can sag or settle, creating low spots where water collects instead of flowing to gutters or drains. This is often due to structural issues, deteriorated support, or inadequate initial installation.

Clogged Drains or Gutters Debris like leaves, dirt, and moss can block roof drains, gutters, or downspouts, preventing water from flowing away. Regular cleaning (especially in fall and spring) can prevent this. Check if your gutters are overflowing or if drain openings are blocked.

Damaged Roofing Material Cracks, punctures, or deterioration in your TPO, EPDM, or tar-based flat roof material can prevent proper water shedding. This is especially likely if the roof is aging or has sustained storm damage.

What You Should Do First, have a professional roofer inspect the roof to diagnose the exact cause—pooling water is a sign the roof isn't performing correctly and can lead to leaks, structural damage, and premature failure. Don't ignore it!

Depending on what they find, solutions might range from simple drain cleaning to re-sloping the roof or replacing the membrane. If your roof is older (over 15-20 years for TPO/EPDM), replacement might be more cost-effective than repairs.

Next Steps Search for local roofers on roofer.city who specialize in flat roof repairs and can give you a free inspection and estimate. Most quality contractors can quickly identify whether this is a maintenance issue or a structural problem requiring more extensive work.