How to install a damp proof course for your log cabin or summerhouse

A damp proof course provides a protective layer between the base of your log cabin and the first layer of timber. It will help to prevent any moisture from getting into the bottom of your log cabin and will significantly extend the lifespan of your building. 

In this blog, we’ll explain exactly what a damp proof course is, why you need one and how to install it correctly. 

For information on how to install your damp proof course, watch our full video:

What is a damp proof course?

A damp proof course is a waterproof barrier that is installed between the base of your log cabin or summerhouse and the timber wall logs at the bottom of the building. Usually, it’s installed on top of the base, underneath the first layer of timber logs.

The damp proof course will stop moisture gathering on the base or the ground from travelling up into the timber.

Why does your log cabin or summerhouse need a damp proof course?

Once your log cabin or summerhouse has been built, you will need to treat the timber to protect it from the elements. However, this does not always mean that it’s completely protected from moisture rising from below. The first layer of logs sits closest to the ground so it’s most at risk from moisture absorption. 

Without a damp proof course, your log cabin is exposed to damp, staining, warping, mould and rot over time, which can cause timber to move and twist and can significantly affect the lifespan of your log cabin. 

We recommend installing a damp proof course for any log cabin or summerhouse, but particularly if your garden is damp or shaded or exposed to heavy rain. 

The damp proof course should be fitted before you lay the first layer of wall logs.

Installing your damp proof course

Here’s our step-by-step guide to installing a damp proof course for your log cabin or summerhouse:

Step one: Tools and materials you’ll need

Before you start, make sure you have everything you need, including: 

• 100mm (depending on the size of your building) damp proof course roll or tape 

• Stanley knife 

• Tape measure 

• Pencil or marker 

• Straight edge

• Spirit level

Step two: Cut to size

Cut the damp proof course to the correct size before you start to make installation easier. You’ll need to measure the perimeter of your garden building where the first layer of wall logs will sit.

Step three: Lay the damp proof course underneath the foundation beams

Place the strips of damp proof course under the foundation beams of your log cabin, directly onto the base to protect the first layer of logs. 

Make sure the damp proof course sits flat with no wrinkles and that it follows the exact line of the walls. Keep the edge flush with the outside edge of the foundation beams for the best results. There should be an overlap or overhang on the inside of the building. 

To stop it from shifting while you’re installing the rest of it, we recommend temporarily tacking it into place so you can make adjustments if needed. You can then secure it once you’re happy.

A simple step to protect your garden building over the long term

Installing a damp proof course is a quick and simple step that offers long-term protection for your garden building. This will provide you with a space that you can use and enjoy for years to come and will protect your investment. 

The damp proof course creates a barrier between the base of your garden building and the timber to prevent problems such as damp, staining, warping and rotting. 

In our next blog, you’ll learn more about the foundation beams of your log cabin and how to install them.