There are several ways, actually. By not having rain gutters to direct the flow of rain running off of your roof, it is possible to undermine the concrete that is the very foundation of your home. No rain gutters can also allow run-off to enter your home beneath exterior doors, causing massive interior damages. The possible damages are not limited to your foundation, either: Doors can begin to warp and the moisture buildup at exterior walls can be a root cause of mold in your home. Adding rain gutters to your home is an inexpensive way to help avoid what could be catastrophic repair costs in the future.