Storm damage that shows up later: how a roof deteriorates after a big blow

Newcastle and big weather

Newcastle sits on a stretch of coast that is regularly hit by east coast lows, intense low-pressure systems that bring days of gale-force wind, heavy rain and big seas. The June 2007 storm, remembered for the bulk carrier Pasha Bulker running aground at Nobbys Beach, is the best-known example, but significant lows and severe thunderstorms with hail and damaging wind come through the Hunter most years.

Each event leaves two kinds of roof damage: the kind you see immediately, and the kind that develops afterward.

Immediate damage

The obvious damage includes:

• sheets lifted or torn away at the edges
• tiles blown off ridges, hips and verges
• branches or whole trees on the roof
• gutters pulled off or overflowing into eaves
• hail holes in skylights, broken tiles, dented steel
• water through the ceiling

These are dealt with first, usually by a make-safe: tarps, temporary sheets, replaced tiles enough to close the roof, and clearing debris. The permanent repair comes after.

Hidden damage that develops

The second category is what this guide is really about.

Cracked and shifted tiles

Hail and flying debris crack tiles in ways that are hard to see from the ground. A hairline crack may not leak in the next shower. Over months, water works into it, freezes and thaws occasionally on cold mornings, and the crack widens. Tiles that shifted slightly in wind may now overlap less, letting wind-driven rain past.

Loosened ridge capping

Ridge caps on tile roofs are held by mortar bedding and pointing. Strong wind can flex the caps and crack the bedding without moving them visibly. The next big rain then finds its way under the caps.

Fixings pulled or bent

On steel roofs, strong uplift can loosen screws or tear the sheet around them. A sheet that is still in place but slightly loose will flutter in the next wind, enlarging the holes.

Lifted flashings

Flashings along walls, chimneys and skylights can be bent or pulled away from their sealant. Water then runs behind them. The resulting leak may appear well away from the flashing itself.

Saturated insulation and timber

If water got into the roof space, insulation can stay wet for a long time, compressing and losing much of its value. Wet timber and plasterboard can grow mould and, if wet repeatedly, rot. Ceilings that were soaked can sag weeks later.

Debris left in valleys and gutters

Storms strip leaves and twigs from trees and dump them in valleys and gutters. The next heavy rain overflows the blocked valley into the roof space, producing a leak that looks unrelated to the storm.

A timeline of what to check

Within the first day or two (safely, from the ground and inside):

1. Walk around the house and look at the roof with binoculars.
2. Look for missing or displaced tiles, lifted sheet edges, bent flashings and sagging gutters.
3. Check ceilings in every room for stains, bubbles or sagging.
4. If you can safely access the roof space, look for daylight, wet insulation and dripping.
5. Photograph everything with dates.

Within a few weeks:

1. Have a roofer inspect the roof surface, valleys, ridges, flashings and fixings.
2. Have gutters and valleys cleared.
3. Ask for photos of any damage found and a written report if you are claiming.

Over the following months:

1. Recheck ceilings after the next few heavy rains.
2. Watch for musty smells, mould spots and peeling paint on ceilings.
3. Call the roofer back if stains appear or grow.

Insurance: what generally helps

Home insurance policies commonly cover sudden storm damage and exclude gradual deterioration, wear and tear, and rust. Policies differ, so read yours and talk to your insurer. Things that generally help a claim:

• reporting the damage promptly
• taking photos and videos before temporary repairs
• keeping receipts for make-safe work
• getting a roofer's written report describing the damage and its likely cause
• not throwing away damaged materials until the insurer says you can

Insurers may send their own assessor. You are entitled to get your own quote as well.

When storm damage tips a roof into replacement

A storm can reveal that a roof was near the end anyway. If the inspection finds brittle tiles that crumble when touched, rust through sheets beyond the storm damage, or rotten battens, the roofer may recommend replacement. Insurance usually covers the storm damage, not the pre-existing condition. A clear report helps separate the two. Our guide to roof leaks versus full roof replacement explains how that call is made.

Reducing the damage next time

• Keep trees trimmed back from the roof, especially branches overhanging the house.
• Clean gutters and valleys before winter and spring storm seasons.
• Have ridges, flashings and fixings checked every few years on older roofs.
• On re-roofs, ask about fixings and batten tie-downs suited to the wind exposure.
• Add sarking or a blanket when re-roofing, so wind-driven rain has a second barrier.

When to call

If water is coming in, call straight away and say it is urgent; read emergency roof work in Newcastle for the first steps. If the storm has passed and you just want the roof checked, book an inspection. Roof repairs are usually enough for storm damage on a sound roof.