Ventilate under the mattress

Moisture needs a way out

People release moisture while sleeping. When a mattress sits against a cold, non-breathable platform, moisture can remain trapped at the underside. We worried about that from the beginning, so we drilled a large number of ventilation holes through the plywood.

The mattress can breathe from above, and the holes give the underside an airflow path. Removing all those circles of plywood also removed some weight. We drilled so many holes that the drill literally started smoking—a real build memory, not a method I recommend repeating.

Other ways to create the same path

Builders also use slatted platforms, slots, or ventilation spacer products. We have not tested those options here. Whatever approach you choose, think about the whole airflow path rather than adding openings that remain blocked by storage underneath.