How waterproof are your garden sheds?Updated 2 months ago

Our sheds are completely waterproof, provided they are installed and maintained correctly.

The only additional things we advise you to do once you’ve assembled your shed would be to add some silicone to the windows and this will ensure that water cannot get in. This is advised in the build instructions. 

We also recommend that our Premium range of sheds is treated with a waterproofing as soon as possible, this is because pressure-treated timber has the treatment embedded deep within the timber rather than sitting on the surface. This offers excellent protection from; rot, mould, and insect infestation but does make the timber more prone to absorbing moisture.

Timber is naturally porous, and while pressure treatment offers significant benefits—such as protection against rot—it does not make the wood waterproof. In fact, freshly pressure-treated timber can still retain moisture, which may increase its susceptibility to absorbing rainwater.

This occurs because:
 • When timber is already damp, its fibres expand, making it more receptive to further moisture.
 • If treatment is applied to wood that has not fully dried, it may not be fully absorbed or could trap moisture inside, potentially reducing its effectiveness.

To ensure the longevity of your shed, we require the application of a high-quality waterproofing preserver as soon as it is installed. To ensure a waterproof building, always allow the timber to dry completely before applying any treatment.

Top reasons why our sheds are waterproof:

Shiplap Cladding

Our shiplap sheds come in shiplap tongue and groove cladding which acts as a control element to direct water safely down the outside wall of the shed and not into the shed, preventing infiltration into the garden building.

Polyester Felt 

Our entire range comes with polyester felt as standard. This prevents water from getting in to the building but still allows the roof timber to breathe.

The below video explains the benefits of this felt.

Toughened glass with PVC sills

Our windows are toughened and our shiplap sheds have PVC sills – this ensures any water running down the windows doesn’t enter the shed as the sills protect the timber.