A softwash is a method of cleaning that was developed to reduce the side effects of high pressure cleaning on delecate surfaces. Common things you shouldn't pressure wash: your roof, home siding, and delicate wood. For these sensitive surfaces, you want to use the least amount of pressure possible while maitaining and effective cleaning. Softwashing lets chemicals do the work while the pressure washer is only used to rinse with high volume and low pressure - less pressure than a garden hose.