How to Prevent Condensation in a Metal Shed

What is condensation? + Stopping condensation in a metal shed

You’ve no doubt seen condensation on walls and ceilings, as a result of rising dampness and wondered what actually causes this to happen.

Condensation happens when surface temperature, air, and water vapor collide, causing droplets of moisture that cover surfaces of walls, ceilings, and many other internal surfaces. To understand how vapor is created, we need to understand the process of evaporation (see, What is Evaporation?). In extreme weather conditions, it has been known for these water droplets to actually freeze inside.

The risk of condensation depends on how moist the air is and how cold the shed surfaces are. Consideration must be given to your shed location, as a poor choice of location can increase the risk of condensation build-up.

What is Evaporation?

Particles in a liquid have contrasting energies and some of these particles will have enough energy to escape and become a gas (vapor). The particles that are left in the liquid have a lower average kinetic energy than before, meaning that the liquid cools down and evaporation happens. Think about sweat? It cools you down right? The sweat that your body produces absorbs the energy from your skin so that it can continue to evaporate.

Asgard Metal Sheds Have Integrated Ventilation

Reduce condensation in your metal shed

The image above shows how air flows freely through the ventilation system that is built-in into all roofs of Asgard sheds.

Asgard Sheds & Storms - Weatherproof Storage

How to Damp-Proof Metal Sheds

Because Asgard sheds benefit from a unique ventilation system, the risk of condensation is greatly reduced. For this ventilation system to be effective you must allow sufficient space for air to circulate in and around your shed. This is particularly true if situating your shed near heavily planted areas i.e. near to conifers, trees, or bushes. If you situate your shed too near to shrubbery or large garden plants the risk of condensation is greatly increased. Try and allow as much space as possible between the shed and the foliage.

Some Asgard storage sheds (Motorcycle storage range, The Flexistore garden shed range, and large bike garages) have additional vents for even more airflow inside.

Is my shed leaking?

Probably not!  Asgard sheds are built inside out, gaps are pretty much zero in our units.  Any water sneaking in is most likely to be an installation issue, such as a base that is not level, causing the doors to misalign or the rubber bungs have been missed in the base (they fill the pre-drilled fixing holes if not bolting to the ground).  Condensation is rare but possible, though even that can be eliminated most of the time with a good, solid base and the correct positioning, away from plants or other structures.

Water Ingress Checklist.

  • You MUST ensure the bungs are in place all around the unit and the correct way around. THIS IS THE MOST COMMON CAUSE OF WATER INGRESS.
  • In the base – if you do not bolt the unit down to the ground YOU MUST insert the bungs the correct way around as per instructions.
  • In the base, if bolting down to the ground – YOU MUST screw the bolts in straight, if they are not straight they will let water in. If in doubt add silicone around the bolt heads.
  • In the base sides - YOU MUST insert the bungs as per instructions.
  • You must brush off snow and ice, or the temperature inside will drop and freeze inside the unit.
  • If you put a hot bike into a cold shed, you will cause moisture - you must allow the bike to cool a little before closing the doors.


  • You MUST position the unit away from trees and shrubs.
  • You MUST have a suitable base at LEAST 50mm thick.
  • If there is a spillage/ or water has got inside the unit you MUST wipe it up - or this will continually evaporate and condense and give the impression of a constant leak.

Bike Storage

What's does condensation mean for your bike? Putting a muddy wet mountain bike inside a cold shed will produce moisture. This is not condensation as such, but liquid drying off from the mud. If possible try and clean your bikes before you put them into storage. Although we know this is not always possible on a cold day after a long ride.

Condensation in a metal shed

Motorcycle Storage

The Asgard range of motorcycle storage has been designed to be practical. It features not only the standard vent system but also extra side vents to allow fumes and moisture from your motorbike to escape. All this ventilation helps to reduce condensation inside the motorcycle garage, keeping your motorcycle in great condition throughout the year, whether it is being stored long-term or short-term.

Tip: After a long ride your bike will be very hot. If you do not allow your motorcycle to cool before storing it inside the unit you will increase the risk of damp/ causing moisture.

metal shed condensation

Plants, shrubs and walls

Try and avoid putting your metal shed too close to trees and shrubs, as this will minimise condensation inside your shed. Overnight - trees and shrubs give off moisture, which will enter your metal shed through the ventilation holes and appear to be condensation. If this happens, you need to trim your hedges and other foliage.

If you place your shed too close to a wall, again you may find moisture ingress, as the air is unable to flow around the unit and through the ventilation holes. If you do find moisture present, resite your shed.

metal sheds and condensation distance from shrubs metal sheds and condensation minimum distance

Long Term Storage

If you are using your metal shed for long-term storage, it’s important that you check the contents periodically for any signs of damp. In extreme weather, it is possible some moisture may form inside the unit. If a small amount of moisture is present, dry it up as soon as possible.


Tools and Equipment to Prevent Condensation

If you have persistent problems with moisture, for example in extreme weather conditions, consider buying a domestic moisture trap. Available at most DIY stores for a few pounds each. These will soak up any excess airborne moisture and reduce damage caused by shed condensation. It is the responsibility of the customer to periodically check for moisture inside the shed. Asgard takes no responsibility for damages caused by moisture.  The customer must take appropriate actions to reduce or remove the moisture.

Insulated Asgard Shed

Asgard sheds & extreme weather


Heat and Metal Sheds

Asgard design and manufactures some of the toughest storage sheds in the UK.  To ensure our sheds are tough and weatherproof, we make all of our sheds from heavy-gauge, Galvanised steel.  The nature of metal does mean the shed may be hot to the touch or get warm inside if built in an area that gets direct sunlight for an extended period of time. If you are storing goods and products inside the unit that may be damaged by excessive heat, we recommend you build your shed in partial shade or in an area that will not get “peak” sunshine periods (normally 10am -1pm).  Asgard takes no responsibility for damage caused to person or property as a result of heat.  Suitable positioning of the unit remains the responsibility of the customer.