Basement under water – preventive measures and first, important steps

As beautiful as summer is, it also bringsplenty of stormswith yourself. And heavy downpours have a dangerous long-term consequence: flooding. Once a certain amount of water is reached, the soil can no longer absorb water; it continues to flow into rivers and lakes, which then become full at some point and overflow. A basement full of water is just one of the terrible consequences of flooding and flooding. But whoever has the exact problem should not despair straight away and do rash and hasty things. Because these could cause just as much damage as acting too late and could even be life-threatening. So what should you do if your basement is flooded? And what are appropriate preventative measures? We'll explain it to you!

Preventing a basement from flooding

The easiest way to protect your home from flooding is to still be in the planning stages. Protective measures are not only recommended in flood risk areas. Flooding could also occur in other regions for various reasons. You should therefore inform your construction company about any structural measures. Those that prevent a cellar from flooding and can be planned during the construction phase depending on needs and terrain are:

Measures before the start of construction

  • Sealing, barrier plaster and drainage systems, which prevent water from penetrating through the walls.
  • Black and white tubs
  • Determination of the design water level, i.e. the highest water level that has ever been measured at the location of the building to be built. The planner determines this.
  • The housebuild elevated.
  • Backflow flapsin the pipes prevent water from overflowing sewersvia the water pipesof the house (are usually even mandatory).
  • You should theDo not seal outdoor areas too much, because the more asphalt, concrete or other sealing materials spread across the property, the less water the soil can absorb. Therefore, use materials that can absorb water (gravel or special paving stones) and leave enough green space.

What you can retrofit with to avoid a basement under water

  • Backflow flapsfor the pipes can be retrofitted.
  • Steps in front of doorscan protect ground-level buildings from flood penetration. A cellar door in particular should be equipped with such a step. To ensure that it really protects your basement from being flooded, a height of 10 to 15 centimeters is recommended.
  • Rain barrels or water storage tankscan collect excess rainwater and thus relieve the soil by gradually releasing the water. They can be installed in the ground and are not visible. The collected rainwater will also be useful for watering in the hot summer months.
  • speed bumpsare for houses that are in a valleyor on a slope, very practical because they prevent water from reaching the property. However, keep in mind that such an earth dam also requires a building permit.
  • Backsplashesare built around basement windows to prevent water from entering through these weak points. Alsopressure-waterproof basement windowsare possible.
  • Closures for building openingscan prevent a basement from being flooded.
  • Mobile protective elementscan protect against flooding of the house if they are installed in a timely manner. These include bulkhead panels and stop beam systems that are attached to building openings.

Of course, you can consider and have any retrofitting elements installed when you are building your house. Also remember: Just because you have taken numerous protective measures, there is no guarantee that the basement will not flood one day. You should be aware of this.

Basement under water – what to do?

So it's important not to rush anything if the basement is flooded. As frightening as a basement filled with water may seem at first, stay calm. If you act incorrectly, you could even endanger your life or worsen the damage. So, you have water in the basement – ​​what do you do now, step by step?

1. Basement full - what to do? Don't go into the water!

Also have basementsa power supply. Therefore it would be life-threatening to enter the water. Instead, go to the fuse box and turn on the main fuse to prevent short circuits. But the fact is that the fuse box is often located in the basement. So, what do you do if your basement floods if you can't get to the safety device without entering the water? Then definitely call the fire department!

It's not just the electricity that poses danger. Dangerous substances stored in the basement could also have mixed with the water (e.g. heating oil). This is another reason why the fire brigade should be called in, as the Federal Office for Civil Protection and Disaster Assistance (BBK) recommends. As a precaution, you can also turn off the water via the main tap until the fire department arrives.

2. Basement under water – let water sink by itself

If the basement is under water, it is best to start pumping it out straight away. But this can turn out to be fatal if you are in too much of a hurry. As difficult as it may be, in some situations you have to wait until the water level drops on its own. This is necessary when the water level is particularly high. Generally speaking, the outside water level is lower than the water level inside the house should be. Only then should you pump water from the basement.

3. Notify the insurance company, document the situation and call in experts

It is clear that you have to get rid of the water as quickly as possible so that the drywall, wooden elements in the construction and insulation do not become saturated. But you should discuss this step with experts. In some situations, pumping out is not recommended if the basement is under water - for example, if mud and water have even penetrated through the floor slab. Sometimes you even have to flood the basement.

Therefore: Contact the insurance company to act correctly and not lose your insurance claims. It will explain to you whether you should contact a structural engineer and building expert. Then you can document everything. Take photos of the situation. These things will also be documented later by the dedicated experts and after the water has gone again, which you can also do. Inquirewith the insurance, to what extent an expert is necessary. Until then, leave everything as it is and don't throw anything away!

4. Pumping

Before you start pumping out, you should not only be sure that no more water will seep in. The groundwater level should also have fallen back to its normal level. An expert can best assess all of this. Under no circumstances should you decide for yourself, because mistakes can have dire consequences: from flooding and swelling to cracks in the masonry and problems with the statics of the house.

5. Start cleaning

You are now finally free of the water, whatever the route. But the matter is far from over. Because now the cleaning is happening and it is more important than you might think. Any mud should be removed while it is still wet because once it dries, it can sometimes become as hard as concrete. You can rinse off muddy dirt on the walls immediately. Don't wait until it dries. It is also important that mud and water do not come into contact with the skin, as they can contain dangerous substances. Wear waterproof protective clothing as well as gloves and rubber boots!

Mud that hasn't come in through the windows or doors could be a red flag. If this has penetrated through the sewer system, i.e. drains, or even through the floor slab, it probably means that the statics of the house are damaged. This is checked by experts.

Remove carpet and/or furniture. It's best to put them outside to dry. If this is not possible, at least raise the furniture by placing it on blocks or stones. This will allow air to circulate better underneath them and dry the area. Also ventilate the basement rooms. As long as it doesn't rain, you can leave the windows and doors open all the time.

6. Dry basement rooms

Since the basement was under water, there is of course plenty of moisture in the rooms despite the pumping out. To avoid mold formation, odors and other problems, the basement room should be dried naturally. Simple ventilation is not sufficient here. Instead, get special dryers. You can either rent them or buy them for prices between 100 and 150 euros.

However, construction experts point out that a dryer alone is not always enough. Screed, drywall and hidden building materials could prove to be more of a challenge. For this reason, you should also hire an expert here. In addition to any impact sound insulation, they will also take a drill core in order to better assess the condition.

Tips to reduce potential damage from a submerged basement

  • Inform everyone in the household about the importance and operation of the main fuse. Children in particular should know that in the event of a floodunder no circumstances enter the watershould!
  • Store all items in the basement on shelves. These are preferably made of metal.
  • Any electrical devices are not placed directly on the floor, but rather elevated at least 15 cm (e.g. on a platform).
  • In risk regions where flooding can occur more often, the electrical installations and heating systems could be relocated to the upper floors.
  • Be careful what you store in the basement: avoid dangerous substances and valuables.
  • You should secure heating oil tanks by anchoring them. If the basement is under water, they could float up.
  • Wallpaper and carpets are less suitable for basement rooms. Decide against standard screed and also use tiles.
  • Sockets should be located higher up in the basement.

What needs to be taken into account after the disaster?

  • Do not drink water from the tap for the time being. Instead, use mineral water, even for cooking!
  • Before you use the drinking water pipes again, rinse them thoroughly.
  • Do not eat or smoke during cleanup! Fire (e.g. from matches or lighters) may also not be used.
  • The power and gas lines as well as electrical devices will only be switched on again once everything is dry. This decision should be made by a professional.