Porta potty has to sit on our lawn for the whole bathroom remodel. Will it kill the grass or crack sprinkler heads?

Yes, a standard portable toilet sitting on your lawn for six weeks will likely kill the grass underneath it and could crack sprinkler heads if placed directly on one. Your plan to use a flat spot on the side lawn is common when the driveway is occupied, but it requires preparation to avoid damage.

For the sprinkler heads, mark their approximate locations with small flags or stakes before the unit is delivered. The driver can then avoid placing the unit directly on a head. The weight of an empty standard unit is about 200 pounds, which is enough to crack a plastic sprinkler head.

To prevent killing the grass, place a barrier under the unit. Plywood or pavers work well. A sheet of 3/4-inch plywood, larger than the unit's footprint, distributes the weight and blocks sunlight. Even with a barrier, the grass will be stressed from lack of light and air, but it will likely recover faster than if the unit sat directly on the lawn. Reseeding in the spring is a good backup plan.

For the service visits, ensure the vacuum truck has clear access to the unit's location each week. The truck needs to park within about 25 feet. If the truck cannot reach the unit, it counts as a missed service, and you may be billed for the trip. Discuss the access path with your rental company when you schedule the delivery.