Cold rooms are modern cellars. They are designed to be underground and their purpose is to be cold enough to store preserves and other food.
Most of them are below a porch, therefore are technically underground spaces that are on the exterior of a home, hence they have no insulation but they have ventilation to allow for air exchange.
The way cold rooms have been built has changed over the years and we still find them in their original state from 50 years ago. In this blog we will discuss how a cold room is supposed to be, in contrast to how many people use them.

What should a cold room look like?
- Cold rooms should not have any insulation of any type. This defeat the purpose of the cold room, which is to be colder than the rest of the house.
- Cold rooms must have some sort of inert ventilation. This is usually a hole in the concrete with a vent cover at the exterior to stop the entry of pests. In the past, the building code allowed a small window to be the ventilation but this was not practical, therefore the majority of the time these cold rooms are damp and musty because no one would open the window. Cold rooms do not need mechanical ventilation such as a ventilation fan.
- Cold rooms must have a metal insulated door or a solid wood door, going from the house to the cold room and this door has to be fully sealed at the sides with weather stripping at the bottom. This stops warm air from the basement area to enter the cold room.
- There is usually one light fixture in this area to provide some light.
Common issues we see in cold rooms:
- The most common issue with the cold room is the musty smell. That is usually the result of the lack of ventilation, a non-insulated door, the door not being sealed properly or sometimes there is moisture penetration from the exterior.
- There is styrofoam insulation installed on the walls and ceilings. Typically the insulation has a low R-value which doesn’t do much and this defeats the purpose of the cold room which is to be cold.
- The cold room is used for the storage of personal items such as clothes, boxes etc. There should be no organic material stored in a cold room. By nature, cold rooms are moist and cold and this will give mould the chance to grow.
- The vent is sealed because the cold room is “getting too cold”. This will happen in the winter in Canada. Ventilation is needed in the cold room year-round and it should not be closed up.
- A hollow wood door is installed. This is very wrong because the warm air will enter the cold room and create condensation in the cold room and will create an environment for mould growth.

FAQs:
- Do I have to keep my cold room and use it as one? Not if you don’t want to. The cold room can be insulated properly and turned into a storage room. Spray foam insulation is the best option for this location as it seals everything and acts as a vapour barrier also.
- Can I remove the door completely? No, you cannot. The cold room is an exterior space which will be colder. Removing the door will create condensation in the cold room and allow cold air to enter your basement.
- Can I use it as storage for food other than in glass containers? No, you cannot. The cold room is moist by nature and this will lead your food to spoil. We will not discuss in this blog, the practice of hanging sausages and other meat products in the cold room to dry cure.
- Can I remove the wood from the cold room ceiling? Yes, you can. Typically, this wood was just used to form the concrete for the porch. It is not structural in any way. If the form is metal, it cannot be removed. It is normal for this metal form to rust over time.
- Is mould normal in the cold room? Mould is not normal in any space inside the home. If there is mould in your cold room, then there is an issue that has to be addressed.
- Should I install a ventilation fan in the cold room? No, it is not required and not worth the trouble. All that is needed is a ventilation hole in the concrete or two if the cold room is large.