Moisture in the garage - what to do?

For most garages, the moisture comes from several sources. The flat roof, lack of insulation and a wet car regularly bring new moisture into the unheated room. How these problems despite the poor ventilation options in the garage can be eliminated or at least sustainably contained, we show here.

Problem moisture

The humidity in a garage causes the car to age and rust faster. In the end, this will cost a lot of money, as the loss in value and the repairs amount to several thousand euros over the years, which can easily be saved with a well-kept dry garage.

These problems cause damage from moisture:

  • leaking flat roof
  • poor or missing insulation
  • unsealed bottom plate
  • Wetness introduced by the car
  • poor cross ventilation

Insulate flat roof

First, make sure that the garage roof is really tight. Then the roof should be insulated from the inside. These are polystyrene panels that are glued from the inside. If the statics allow it, a green roof is the best solution.


The moisture from the flat roof, together with the moisture brought in by the car, can penetrate into the garage floor plate. Therefore, the floor should be sealed. However, the garage must be completely dry. There are different seals for the floor, which are applied like a paint.

An unsealed floor initially only absorbs moisture, but later it bursts more and more due to frost in winter and becomes brittle and brittle.

Wet or snowy car

With the car more moisture is carried into the garage, as you can imagine. This does not just happen when there is a lot of snow and ice under the mudguards. Even the moisture that is stuck to the car due to fog can cause considerable damage, not only to the car itself but also to the garage.

Of course, the car can not be completely dried before it gets into the garage. Therefore, if possible, do not close the garage when the vehicle is wet or damp. Leave the gate at least slightly open. At this point, a sectional door pays off that does not protrude at an angle when it is open. Similar to a venetian blind, this door can simply be left a few inches wide.

Sweep snow

If the car is once put into the garage with a lot of snow, the puddles should be swept out as soon as possible. It may take a bit of work to drive the car out again and sweep out the garage, but it takes too long to flush out that amount of water naturally.

Install additional ventilation

If the garage is extremely unfavorable, it should be considered to cut additional ventilation holes on opposite sides of the garage, directly under the roof in the walls. However, these must be protected with a lamellar grid against ingress of rainwater. Through these holes, a cross ventilation is generated, which blows out the moisture downright.

Even more professional you can meet the humidity in the garage with a humidity controller (see here at the garage manufacturer Rekers).

Tips & Tricks

Hang a hygrometer in your garage to keep an eye on the actual humidity. If it is regularly over 90 percent, it is advisable to renovate the garage from scratch.

Video Board: WIZZVENT, the Ultimate Moisture Control Solution for Garages!