Roof Repair or Replacement? Questions for a Philadelphia House

Roofs Philadelphia connects homeowners with independent local roofing contractors. We do not perform roofing work.

This page has no phone number, on purpose. The line on the rest of this site connects homeowners who are planning a new roof or a full replacement; it does not take repair calls. If your roof needs a repair, a roofer who does repairs is the person to call, and this page tries to help you tell which case you are in.

Usually a repair

One leak on a roof with years of life left. A single spot, a flashing joint at a chimney or vent, or a seam that opened, on a roof well inside HUD's useful life for its material (15 years for EPDM or TPO, 20 for asphalt shingles or a built-up roof with gravel, 75 for slate).
Storm damage to a small area. A few lost shingles or slates, a torn corner of membrane.
A clogged drain or scupper. Water standing because the drain is blocked, not because the roof has lost its slope. The City's Rowhouse Manual says the roof "must slope to the downspout."

Usually a replacement

The roof is at or past its expected life, and the problems are spread across it rather than in one place.
Two layers are already on it. Under the City's EZ re-roofing standard the next roof must start with a full tear-off, so patching an old second layer buys only a little time.
The covering is water-damaged or deteriorated across the roof: the standard's own words for a roof that cannot be covered over.
Water stands across a flat roof because the slope is gone, which only rebuilding the roof corrects.
The deck is soft in many places. Once deck boards have to be replaced over a large area, the roof above them comes off anyway.

In between

A slate roof with sound slate and failed flashing is often a repair of the flashing; the EZ standard even allows sound slate to be relaid. A flat roof with one bad section and a sound remainder may be patched once. Get the reasons in writing either way, and if two roofers disagree, ask each to point to the condition on the roof that decided it.

If it turns out to be a replacement

Start with when to replace, what a replacement includes and roof permits. The home page explains the line for new roofs and full replacements.

Questions

Should I repair or replace my roof?

One leak, a small storm-damaged area or a clogged drain on a roof well inside its expected life is usually a repair. A roof at or past its expected life with problems spread across it, two layers already on, a deteriorated covering, a lost slope or a deck soft in many places is usually a replacement.

Is it worth patching a roof that already has two layers?

Usually not for long. Under the City’s EZ re-roofing standard the next roof over two layers must start with a full tear-off, so patching the old second layer buys only a little time.

Can a slate roof with failed flashing be repaired instead of replaced?

Often, yes. A slate roof with sound slate and failed flashing is often a repair of the flashing, and the EZ standard even allows sound slate to be relaid.

What if two roofers disagree on repair or replacement?

Get each one’s reasons in writing, and ask each to point to the condition on the roof that decided it.

Repair or replace the roof?