How to ventilate your shed

How to ventilate your shed

Baking hot in summer, freezing during the winter and always damp. If this describes your garden shed then chances are it’s a place you dump your rusty tools and otherwise avoid like the plague. 

But by installing an adequate ventilation system, you can keep the heat and damp under control, creating an environment that’s pleasant and appealing to work in. Here’s how.

At a glance:

  1. Ventilation for smaller sheds - install vents and roof windows
  2. How to ventilate a large shed - install a whirligig or electric fan
  3. Heating and ventilating your home office - monitor humidity and install an air source heat pump

You’ll get so much more use from your shed if it’s a comfortable place to be. Make sure there's adequate airflow to ensure better temperature control and a drier atmosphere, which helps prevent tools and electrical equipment from degrading. Good ventilation helps you get the most from your craft room, workshop or as a space to chill, without furniture and materials getting smelly and mouldy.

Ventilating a small shed

Small Waltons wooden shed with door open
Keep your shed doors open as much as you can
Image: 4 x 3 Overlap Single Door Apex Wooden Garden Shed from Waltons

Opening and closing windows and leaving the door open are the most basic ways to change the air inside your shed, but you need a solution that works for you even when you’re not there. If you own a shed smaller than approximately 10’ x 6’, it’s important to install a passive ventilation system, especially to prevent build-up of fumes if you use your shed to store petrol and other solvents.

Install vents

Ventilation on side of a wooden house
A small ventilation grille on opposite walls will provide good air flow
Image: White_Fox/Shutterstock

If you’re installing a new shed, give thought to the most common wind direction when deciding where to erect it. Siting your shed so the prevailing airstream hits the gable end is best. By installing two vents, one high up on each gable wall, you’re guaranteed a healthy throughflow of air. Make sure the vents you install are mesh-backed to prevent bugs making a home in your shed. A small ventilation grille on opposite walls will provide good air flow. 

Install venting rooflights to improve your shed's natural lighting as well as letting hot air out of the building. Made of tough, opaque plastic, like a caravan roof vent, these help the air to circulate and fumes from paint or petrol to escape, while a grille keeps creepy crawlies out. Ideal for windowless sheds, they’re lightweight and easy to install.

Install roof windows

Open roof window vent in wooden house
Close skylights to lock in warmth, or open them in warmer weather
Image: Diana Rui/Shutterstock

Go one better by putting in roof windows you can open and close. Skylights are an attractive option if you use your shed as a workshop because they make it so much easier to keep the temperature under control on warm days. By also installing wall vents or leaving the door ajar, hot air rising through open skylights draws cooler air into the building from outside. On cold winter days, windows in your roof maximise heat from the sun.

Ventilating a larger shed

Large wooden workshop with doors open
Larger sheds and workshops need adequate ventilation for the increased space
Image: 20 x 10 Premium Shiplap Apex Workshop from Waltons

Larger sheds over 12’ x 6’ will probably require more throughput of air to freshen the whole space, but this is easy and cost-effective to achieve by installing simple, effective equipment.

Invest in a whirligig

Whirlygig on roof letting in air
Whirligigs are clever contraptions that use wind power to draw hot air out of the building
Image: SantaGig/Shutterstock

We often see these installed on van roofs – the wind pushes a turbine around, which draws air up and out of the vehicle. Wind powered shed vents are larger than their automotive equivalents, but they work in exactly the same way. 

Install your whirligig in accordance with the manufacturer’s instructions, but generally, these ventilation units work best when they’re sited near the apex of the roof, in a central location. Check to make sure that you know where your roof battens are before you cut the hole, so that you don’t damage the structure of the building. 

As with all roof-mounted vents, a whirligig works much more effectively if it’s complemented by gable wall-mounted static vents; to move air through the building, it has to be able to find a way in as well as out.

Install an electric fan

Interior of Waltons Helios Summerhouse turned into a home office
This customer installed an air conditioning unit to cool down their shed-turned-home office
Image: Waltons

To avoid sweltering on hot, windless days, install a solar or mains powered electric fan. Mount this in one gable wall, make sure there’s a static vent in the opposite wall, and switch on whenever you need a draught. This solution is ideal for times when you’re mixing paint, or using solvents or petrol.

Special ventilation solutions for home offices

Waltons Shore 4m x 3m log cabin with double doors open
If you work in your shed you'll need a more permanent solution for cooling down your office
Image: The Shore 4m x 3m log cabin from Waltons

Using your shed as an office or workroom? It’s vital to get the right balance of temperature and humidity control, especially when you’re using the space to house delicate IT equipment. Static vents are a must to let air into and out of the building, but you’ll also need some sort of heating.

A great way to combine heating, cooling and ventilation is to install an air source heat pump. This works a bit like a fridge that can be reversed to pump cool air on hot days and warm air on cold days. Cheap to run, air source heat pumps are an excellent way to keep the temperature in your shed stable.

Good ventilation means you’ll be able to make so much more of your shed. If you’re considering turning the space into a she-shed, man cave, workshop or craft room, or if you just want to be able to store your tools in your shed without them corroding, you now have the knowledge to get your ventilation sorted.


Visit the Waltons help pages or the Waltons blog for advice, tips, and all things sheddie. 

Lead image: 10 x 10 Premium Shiplap Apex Wooden Workshop from Waltons

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