Drainage and rainwater drains

Rainwater refers to all forms of water that come from the sky, such as rain, snow, and hail. The purpose of rainwater drainage is to transport rainwater from the roof and gutters to the sewer system. Rainwater drainage isn't always connected to the sewer system; it ends above ground or in a gravel pit along the facade.

• Please note: you can only visually inspect the above-ground rainwater drainage system (and not its functionality). Asking current residents whether it functions properly and adequately (even during heavy rainfall) can provide clarity. The same applies to underground rainwater drainage systems that are connected to a sewer system or similar.
• Common problems with rainwater drains
• Benefits of disconnecting rainwater drains

If any defects are found in the fastening of the rainwater drains, these defects can usually be easily repaired. The necessary parts can be purchased at any hardware store.

If the rainwater drains have subsided or come apart, repairs will be necessary, particularly at the connections. Parts can be replaced or extended, and repairs are easily possible. Note: because these drains have now subsided, you should consider a possible cause: this is often due to subsidence or irregularities in the soil structure, which pull the drains or sewers downwards.

If the rainwater drainage system overflows and/or there is insufficient drainage or drainage capacity, this could be due to a blockage, break, or other (invisible) defect in the rainwater drainage system, either above or below ground level. Defects can usually be easily located and repaired.

The rainwater drain may not be connected to a sewer system but may end above ground . Ensure that rainwater can drain away unhindered to minimize the burden on the facade. If this drainage system functions properly and drains away from the facade, it can be maintained this way!

• If the drainage from the facade is not functioning optimally, creating a gravel pit or connecting it to a sewer can be a very simple preventive measure to improve drainage.
• If the water drainage capacity is not properly managed, the facade and foundation will be subjected to prolonged water loads. This will lead to flooding of the foundation or masonry, for example.
• Moisture in walls or foundations can lead to (invisible) defects in floor joists, basement walls, weakening of the foundation and soil structure.

If the rainwater drain ends in a (gravel) drain: this is an excellent solution, provided the drain has sufficient storage capacity. Water that continuously loads the facade will eventually cause damage or a moisture problem on the other side of the wall. Therefore, ensure that rainwater is collected unhindered in the drain to relieve the facade as much as possible.

• If the water drainage capacity proves insufficient, the facade and foundation will be subjected to prolonged water loads. This will lead to flooding of the foundation or masonry, for example.
• Moisture in walls or foundations can lead to (invisible) defects in floor joists, basement walls, weakening of the foundation and soil structure.
• At some point, a better solution will be to connect this drainage to a sewer system. This will usually have to be proven in practice!

Read our blog post "Checking your home's sewer system" here. While underground sewers can't be inspected during a building inspection, it's still wise to reserve a building inspection when buying a home. On our website, you'll find all sorts of information and helpful tips that may be helpful during negotiations or when buying a home. A building inspection reservation also gives you more certainty when submitting your offer.