Top 6 hidden dangers of flood damage

Hidden dangers of flood damage

After flooding much of the damage is obvious: furniture may have moved, fabrics and plaster are wet, wallpaper and paint is peeling and there may likely be mud and debris around with a tide-mark indicating the high-water point. Unfortunately, as the cosmetic damage tends to be both obvious and upsetting, all too many people rush to put it right, hiding more serious damage and potentially creating health and safety risks for themselves as they go.

While the effects of a major pipe burst and an external water incursion (such as flood water from a river) have different impacts in many ways, they are similar in others and our discussion below covers both.

We’ll describe 6 hidden dangers to check for if your home or business has been flooded. If this affects you, we provide a flood damage restoration service and if you’d like professional advice on the subject, please give us a call.


1. Damage to electrics, wiring or heating systems

You don’t need a degree in electrical engineering to know that water and electricity don’t mix. Even if your electrical systems were turned off for the duration of the flooding, there may be hidden damage in areas directly affected by the water, as well as areas which are part of the same system. Damage may occur in a number of different ways including direct damage due to the water; elements being displaced by the water and systems affected by short circuits.

During the drying process, moisture from walls, flooring and other materials is extracted into the internal atmosphere and this damp can also affect electric systems.

2. Water system contamination

This is primarily a problem when flooding is due to grey or black water, i.e. water from external sources such as rivers or heavy rainfall or when sewage pipes burst. In these cases it is possible for serious contaminants, such as human or animal faecal matter, industrial chemicals, and oils etc., to get into fresh water systems used for drinking, washing and cleaning. Wells and ground-water springs are at particular risk, but pipework and mains water can also be contaminated.

This can be a real hazard for at-risk groups such as infants, children, the elderly and those who already have compromised immune systems such as cancer patients and pregnant women. This is a strong argument for having in-building water tested before allowing employees or residents to return to normal use of the site.

3. Hidden water remains

Many flood damage victims either can’t afford professional drying services or don’t realise they need them. As a result, once the visible water has retreated or been pumped out, the building is left to dry out of its own accord. This can create hidden pools of water often under flooring or behind walls as well as leaving materials waterlogged for extended periods.

As many homes and businesses are fairly airtight, particularly once sealed against unwanted entries, the water may be trapped in the fabric of the building. This can lead to numerous problems throughout the structure – even in areas unaffected by the flooding and common signs of damp, such as mould and peeling wallpaper, may alert the owner to the problem but perhaps not in time to find and fix the underlying issue.

4. Damage to foundations, joists and underfloor areas

How often do you think about what’s beneath your feet? Most people never do – unless they’ve just stepped in something unpleasant. However, the area beneath the floor is both critical to ensuring the long term stability and safety of a building and the area most likely to be seriously affected by flooding or a burst pipe.

Water can cause damage to foundations, joists and underfloor areas in a number of ways, including direct damage through contact; bursting through structures as pressure builds, physically displacing materials such as sand and gravel; creating or widening holes, waterlogging materials, causing rot and/or weakening, swelling and distortion to materials such as wood, delamination to veneers or laminates and causing rust. If trapped for example inside a damp-proof membrane, water will continue to do damage. As a result, a structure (such as a kitchen floor) may seem fine at first and then over time, develop signs that something is wrong such as a ‘spongy’ feel when stepped on, visual cupping or wetting at the base of the adjoining walls.

5. Problems inside the walls

Water marks, peeling wallpaper or bubbling paint are just the surface signs of water damage and should be treated as such. It is however, essential to check inside the walls for standing water and/or wet insulation, damage to internal systems such as water pipes, electrical systems, gas pipes and more. Joists and structural elements should also be checked for damage as water can cause wood to swell, buckle or distort, compromising the structural integrity of the wall.

Brickwork should also be checked thoroughly as mortar is particularly at risk from flooding and, rendered finishes should be checked for any areas displaying cracking or damage as these can become points of water entry that do not readily allow the trapped water to escape.

6. Mould and mildew

Even the most effective drying processes cannot remove all the water from a property overnight. Damp air and water saturated materials provide excellent environments for mould and mildew to flourish with some moulds able to generate growth in just 48 hours given ideal conditions. These may then affect other parts of the property which were not directly impacted by the flooding. As an example, a burst pipe in the kitchen may cause water damage downstairs and, insufficient drying and ventilation may then stagnate the damp in the house leading to potential mould growth in unaffected areas when the conditions prevail.

Additionally, hidden mould for example inside wall voids is a serious health risk if proper drying hasn’t been concluded. Mould can release spores which can have a serious impact on the health of occupants of a building and vulnerable people including babies, children, the elderly and anyone with a compromised immune system or existing respiratory problems such as asthma are at particular risk.

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