Porta potty for a 4-month farmhouse rebuild. Winterize it?

Yes, you need to ask the rental company for winterization for a standard portable toilet in a Montana winter. Winterization involves the service technician adding a brine or non-toxic antifreeze solution to the holding tank during each service visit to prevent the waste from freezing solid. A standard, non-flushing unit is much easier to winterize than a deluxe flushing model, which has a fresh water tank that can freeze and crack.

For a crew of 5 to 8 people on weekdays, one standard portable toilet meets the minimum requirement of OSHA 1926.51 for construction sites. A hand sanitizer dispenser mounted inside the unit is sufficient for OSHA compliance. A deluxe unit with a sink is not necessary for a small crew, and its water system is more vulnerable to freezing. The four-month duration qualifies as a long-term rental, which often has a lower monthly rental rate. Weekly service is standard, but confirm with the operator that winterization is included in the service plan.

Marcus is right on winterization, but confirm with your rental company that they use a non-toxic antifreeze, not brine, if the waste goes to a local treatment plant that restricts salt. For your crew size, one standard portable toilet meets OSHA 1926.51, but consider a handwash station instead of just a hand sanitizer dispenser, it’s better for mud and grease, and the rental company can winterize it by draining the tank between visits. Your gravel driveway and truck access are ideal; just ensure the unit stays clear of snow buildup around the base to prevent icing.