Power washing can potentially remove concrete sealers, especially if the sealer is old or has degraded over time. The high-pressure water stream used in power washing can strip away the protective sealer layer, leaving the concrete exposed. However, the extent of sealer removal depends on factors such as the type of sealer used, its age and the pressure and temperature settings of the power washer. Newer, high-quality sealers may be more resistant to power washing. If you plan to power wash a sealed concrete surface, it is recommended to consult with professionals like Baird Foundation Repair to ensure the appropriate techniques are used to avoid damaging the sealer or the concrete itself.