1. Article Body
Mobile home roofs fail in a small, predictable set of ways, and the most common complaint is not a leak at all.
Condensation, reported as a leak
The single most misdiagnosed problem in this category.
The cavity above the ceiling is shallow and frequently under ventilated, directly below a metal surface. Warm moist air meets the cold underside, condenses and drips.
The signs: it appears in cold weather rather than during rain, it is worst on the first cold morning after a mild spell, and it shows across an area rather than at a single point.
Sealing the roof will not fix it. Ventilation will.
Seam failure
On an original metal or rolled roof, seams are where water gets in.
Sealant applied at seams ages, shrinks and cracks. The traditional annual resealing routine existed for exactly this reason.
Fastener backout
Thermal movement works screws loose. The washer beneath hardens and stops sealing, and the raised head becomes a path.
Visible from the ground on a sunny day as a line of bright heads.
Perimeter trim and terminations
The edge trim where the roof meets the wall is a junction that moves, and it is rarely inspected.
Water entering here travels down inside the wall rather than dripping into the room, so it does damage for a long time before it announces itself.
Ponding on a shallow roof
A nearly flat roof with any deflection holds water.
On a coated roof, standing water breaks down the coating faster than anywhere else. On a metal roof it accelerates corrosion. Either way, ponding is a real problem rather than a cosmetic one.
Coating breakdown
Coating systems are maintenance products, not permanent roofs. They chalk, thin and lose adhesion, particularly at seams and on the sun exposed elevation.
An owner who coats once and never again has bought a few years, not a roof.
Rust and corrosion
On metal roofs, corrosion starts at cut edges, at fastener penetrations and at any point water sits. Surface rust on a panel face is usually cosmetic for years; rust through at a seam is a water path.
Penetrations
Vents, air conditioning units, satellite mounts, swamp coolers and antenna mounts. Each is a hole, and mobile homes accumulate them.
Hail and wind
Light panels dent under hail and lift at edges under wind. Uplift starts at the perimeter, so check the edges after any storm.
Previous repairs
Many mobile home roofs carry years of accumulated tar, sealant and patches applied by successive owners.
Layered repairs trap water, make diagnosis difficult and have to come off before any proper system goes on.
