For many of us, our shed takes pride of place in our garden, and we spend many hours tinkering with gadgets and fixing tools in it. For some, it’s a home from home; if we want a bit of undisturbed time, we head down to the garden shed and enjoy a little peace and quiet. If the shed is damp, smells of mould and its roof leaks, it won’t be a pleasant place to be in.
More importantly, it is somewhere that we store expensive equipment that can easily be damaged by water such as lawnmowers, strimmers and other power tools. If they get damaged, they can be costly and inconvenient to replace.
Water is the nemesis of sheds, and the one sure place that is certain to get wet when it rains is the roof! While it is important to make sure that other parts of the shed don’t leak or attract moisture, your top priority should be the roof.
The best shed roofing is an investment and will not only prevent leaks but will also protect against other environmental factors, such as sun and snow.

How to Check if Your Garden Shed Is Leaking

Before you waterproof your shed roof, you should check for leaks and where they are coming from. It might not only be the roof that is the problem, as leaks can also come from the doors, windows and walls. Furthermore, it could be an altogether different issue, that of condensation.
The logical time to check for leaks is as soon as possible after it has rained. If you leave it too long, the water might evaporate or dry up and not give you the same clues as to where it is coming from. Look for areas of damp, discoloured wood, puddles or drips coming from the shed’s ceiling.
You can also perform a thorough check for damage - is it wood that has rotted, is the water seeping up through the shed floor or is it coming from the roof?
Once you are sure of the source of the leak, you can get on with repairing or replacing it. If it is the roof that needs waterproofing, you need to find the best type for your needs.

Choosing the Best Type of Roofing Material to Waterproof Your Shed

Certainly, choosing a shed roof water resistance should be at the top of your list of considerations, but there are other factors to take into account as well. You should consider the cost, and how affordable it is, the durability and resilience of the material, how easy it is to install and the longevity of the product. If you are particularly proud of your garden, you might want your roofing choice to be good to look at as well.

EPDM

EPDM which also goes by the less catchy name of ethylene propylene diene terpolymer is at the top of our list, ticking all the right boxes. It is cost-effective, durable, long-lasting and easy to install. It’s also totally waterproof when purchased; it comes in one large sheet so has no seams or areas where water can seep through. It is also eco-friendly and offers UV protection against the sun’s rays. We will dig a little deeper into the benefits of this rubber roofing material shortly but let's look at some other options first.

Felt

Traditional roof felt is the least expensive shed roof material you can purchase. However, its benefits end with its low cost. Felt is one of the least durable shed roofing materials and can’t be expected to last anywhere the length of time that EPDM will. You can expect it to last 5-15 years depending on the quality of the mineral roof felt you buy. It is sold by weight from 15 lb to 90 lb - the higher number, the thicker it is.

Metal Shed Roofing

Metal roofing sheets are a reasonably good option that will make sure that your shed stays waterproof. Metal roofing is available as corrugated sheets or a box profile. As an aesthetic choice, popularity is divided some like the modern look of metal, others not so much. Depending on the environment it is installed in, it can last up to 25 years. However, it’s not a good choice for coastal regions where salt in the air could cause the metal to corrode. Installation is relatively straightforward, but you must make sure it is regularly painted to protect it from rusting.

Wood Shingles

Wood shingles can be made from several types of wood such as redwood, cedar and oak, with the latter being the most expensive. If you want to give your garden shed a natural look, wood shingles are a great option, and they are durable enough to last up to 30 years. It’s one of the more costly options, but it is a great waterproof shed roof option and looks great as well.

Clay Tiles

If you have a sturdy or large shed that can take the strain, then clay roof tiles can be a great choice. They are easy on the eye, offering beautiful aesthetic appeal, and are long-lasting and durable, comparable with EPDM in their lifespan. The installation has become easier with new innovation, and they come in a wide range of designs and styles. Their main downside as a shed roofing material is that they are costly and aren’t suitable for lightweight garden sheds.

Why EPDM Is the Best Waterproof Solution for Your Shed

While all the options above have their pros and cons, EPDM is the most cost-effective waterproof shed roofing available. Once installed, it could even outlast the lifespan of your shed, as this type of rubber roofing has been known to last fifty years or more. It's also affordable to purchase, easy to install as it comes in one piece, and requires little upkeep. You can read more about the waterproof properties of EPDM here.

Other Considerations When Waterproofing Your Shed

Though the roof of your shed is the main surface that you should waterproof, neglecting other areas could still result in your shed becoming damp, musty and mouldy. Here are some other factors to think about to keep the inside of your shed cosy and dry.

Waterproofing Shed Walls

Shed walls can suffer from similar issues to a roof, especially if it is in an exposed position in your garden. On windy days, rain constantly battering at the side of your shed can cause it to leak. Even if you were lucky to inherit or have the forethought to have the shed built in a less exposed area, wear and tear would eventually result in cracks and splits. While your EPDM rubber roofing might last 50 years if not taken care of it is more likely the walls will be the downfall of your shed, not the roof.
There are several options to waterproof the walls of your shed; these include using timber treatments and filling any cracks and gaps you come across with caulking.

Insulating Your Garden Shed

Insulation will not only keep you warmer when you are spending time in your shed during the cooler months; it will all help keep out moisture. There are plenty of different products you can use to insulate your shed - one of the most popular and affordable is bubble wrap. By insulating your shed, it will create a waterproof layer inside and make it more breathable, removing excess moisture.

Painting Your Shed

If you want to kill two birds with one stone, give your shed a little colour and make it more water-resistant then choose waterproof paint. It makes your walls more resilient in a similar way to timber treatment. Once you’ve given your shed a fresh new look with waterproof paint, it won’t need painting again for a few years at least.

Waterproofing Shed Windows and Doors

As with the doors and windows of your home, these are common areas that rain can enter if there are gaps. You can use Silicone-based caulk to fill the gaps and then apply foam weatherstripping around the doors and windows to create a further seal.

Waterproofing a New Shed

If you are installing a new shed from scratch, you are in an enviable position, and you can choose the best place to locate it. It would be best if you avoided areas in your garden where water might tend to pool, aim for a level service that is not low lying. Install it in an area that gets the most sun. As direct sunlight will help evaporate any moisture on your shed after it rains, it lessens the chances of it staying wet for so long.
When you build your shed, make sure it is up off the ground with a base underneath it - by doing this, water from the ground won’t soak into it. Combined with a long-lasting waterproof roof such as an EPDM rubber membrane and a little regular maintenance, your shed should remain moisture-free, and be able to stand the test of time.

How to Install Roof Felt

If you decided to go with this cheaper option, then do realise that it is not as durable or long-lasting as other materials. Still, it's reasonably easy to install, and once you've carried out the task, the next time it will be easy.

Step 1

For a typical A-frame, measure the length and width of one side of the shed roof and multiply by two for the total area. Purchase your roof felt to match the dimensions of your roof.

Step 2

Using a scraper on a long pole, remove any existing felt or shingles from the roof. Clean the roof and remove or drive any nails that are sticking out below the surface.

Step 3

Even though you are waterproofing the roof with felt, it is a good idea to add a layer of weatherproof paint to add extra protection. You can always use this time to paint the walls of your shed as well.

Step 4

Unroll the felt and using 20mm long galvanised nails pound one nail every 30cm around the perimeter of the first piece of felt. Slightly overlap the first piece with the second one and follow the same instructions nailing it to the roof. How many pieces of felt used will depend on the size of your roof.

Step 5

Once the felt is nailed down on either side, centre the last piece over the apex overlapping both sides of the roof and you're finished.

How to Install EPDM

The great thing about EPDM is once it's installed, it is not going to be likely that you will ever have to do the job again. For instance, if you are currently in your thirties, you can expect your newly installed waterproof roofing to be still going strong into your eighties, and if it does need replacing, it will be a job for the grandchildren!

Step 1

Just as you did with installing a felt roof, you need to make sure that you measure it precisely before purchasing your shed roof kit. The kit will include EPDM rubber roof membrane, adhesive, gloves and roller. You'll also require scissors, hammer and galvanised clout nails.

Step 2

Clean the roof, remove any nails and ensure it is dry. Unwrap the EPDM and place it unfolded on the top of your shed. Give it about half an hour to relax.

Step 3

Apply the included adhesive with the roller evenly over the roof surface. Then roll out the membrane using a soft broom to ensure that there are no air bubbles or creases.

Step 4

Trim the membrane to size removing the excess with sharp scissors, leaving around 50 mm overhang.

Step 5

Fold the membrane back on itself and fix in place with the galvanised nails.

Full Instructions Here

In Conclusion

If you want to waterproof a shed, it doesn't have to be a daunting project - a new waterproof shed roof can be installed in a weekend and can last over 50 years, so once done, it's likely you'll never have to do it again. Don't neglect the walls, windows and door of your garden shed to ensure that it is totally waterproof. If you have expensive power tools and gardening gear in your shed, don't leave it too late.