If you have ever driven with a half-full water tank, you know the problem: the water sloshes forward and backward with every acceleration and brake. This sloshing creates noise, puts stress on your tank mountings, and can cause your van to handle differently. Baffles solve this.
What Are Baffles?
Baffles are internal walls in a water tank that break the water into smaller compartments. The water cannot all move at once, so sloshing is dramatically reduced.
Legal Requirements
While not a legal requirement for DIY campervans, professionally built motorhomes often include baffled water tanks to comply with stability standards. A 50L water tank holds 50kg — sloshing shifts that weight unpredictably.
DIY Baffles
If you build your own water tank from food-grade plastic or stainless steel:
- Add vertical baffles every 30-40cm of tank length
- Baffles should have 100-150mm gaps at the bottom (to allow water flow for filling/emptying)
- Each baffle should cover 60-70% of the tank cross-section
- Use 6mm food-grade plastic for the baffle panels
Commercial Baffled Tanks
Most commercial campervan water tanks include baffles:
- Tanks-UK: All tanks above 30L have baffles
- Fiamma: Standard on their underfloor tanks
- Whale: Baffled as standard
No Baffle? Use a Bladder
If your tank has no baffles, install a water bladder instead of a rigid tank. The bladder conforms to the tank shape and the water has no air gap to slosh in.
Conclusion
Baffles are essential for any campervan water tank over 30L. If your tank does not have them, add them during the build or use a water bladder.
