How to damp proof your Shed?

Just had a new Shed installed and it appears to be leaking?

Firstly, it is important not to stress as this is something very commonly known as ‘capillary action’ and is typical within pressure treated timber. It is common for there to be a small amount of moisture still retained within the timbers of your new Shed, and it may take a little time for your Shed to dry out (or ‘cure’) thoroughly before maximum resilience to the elements has occurred (depending upon the environment to which your Shed is subjected (i.e., weather conditions, etc).

The easiest way to overcome this is to keep the Shed adequately aired during this period of time (where possible) and to monitor the situation. Once the timber has fully cured it will no longer take on any further moisture.

Damp proofing your shed helps to stop moisture from damaging the fabric of the building and destroying any tools and equipment stored inside.

Here we cover every possible step to best protecting your Shed from damp and mould:

Lining paper

Lining Paper

Lining paper adds extra protection to a garden structure. Available in a variety of sizes, lengths and grades, Shed Liners create further protection by creating a wind proof and waterproof outer layer. It is a cost-effective option in comparison to insulation. 

Wood Treatment – Cuprinol (oil or waxed base)  

Although our pressure treated wood is inclusive of a 10-year anti rot warranty, pressure treated wood still needs to cure, and therefore applying an oil or waxed based treatment can help assist with this. We recommend doing this at least once a year.

Checking the door and windows:

Overtime, wood can crack and shrink due to natural sources and therefore checking the doors and windows every so often, adding wood filler if necessary, will avoid any rainwater blowing through the gaps.

Heat sources:

Heat is an effective way of keeping damp under control. If you have electrics running into your Shed, it is definitely worth placing a heater inside.

Avoid paraffin and Calor Gas heaters because as well as producing heat, they pump out moisture – causing the exact problem you are trying to eliminate.

Install Shed insulation:

Installing insulation will assist in trapping available heat inside your shed, helping to stabilize the temperature. When the temperature hits it ‘dew’ point, humidity in the air condenses. Cool surfaces such as tools and metals then become wet and soft furnishings swell, grow damp and become a perfect environment for growing mould.

Keep a good airflow:

Attaining a healthy air flow throughout your new Shed after installation will stop moisture build-up. Opening the door and windows every so often will help to ventilate the Shed, keeping moisture levels down as the air is consistently being replaced with new fresh air.


As well as a heater, you might want to install a dehumidifier, particularly if your shed is located on damp ground that doesn’t see much sunlight or if you live in a particularly rainy part of the country or you’re near the coast.

High quality storage:

Investing in quality storage assists in further protecting your tools and equipment. A sealed container or apartment will ensure any damp or mould is kept away. Sealed containers with silicone gel sachets inside are a great option to keeping things dry and undamaged.

If your new Shed is left shut, unheated or leaks, it will grow damp quickly. With regular check-ups and by following our advice above, you can catch this early and enjoy your new ‘mancave’ or ‘she shed’ right from the get go.

Any questions please get in touch: 0800 170 1401