How to Waterproof a Shed Roof & Stop Leaks | S-FIXX
How to Waterproof a Shed Roof – Stop Leaks Without Replacing the Roof
A leaking shed roof doesn’t always mean you need to replace the whole roof.
Small cracks, ageing roofing felt, failed joints and areas around fixings can allow water to get through, particularly after years of exposure to rain, frost and changing temperatures.
In many cases, you can waterproof an existing shed roof by repairing damaged areas and applying a flexible waterproof coating over the surface.
In this guide, we’ll explain how to find the source of a shed roof leak, prepare the roof properly and create a waterproof barrier using a liquid rubber coating.
Why Do Shed Roofs Start Leaking?
Shed roofs spend their entire lives exposed to the British weather.
Over time, roofing materials can deteriorate through UV exposure, rain, frost and repeated expansion and contraction.
Common causes include:
- Cracked or split roofing felt
- Failed overlaps and joints
- Loose or damaged fixings
- Small holes and punctures
- Water collecting in low spots
- Ageing roof coverings
- Failed previous repairs
One of the difficulties with roof leaks is that where you see water inside the shed isn’t necessarily where it’s entering.
Water can get through a small defect and travel underneath the roof covering before appearing somewhere else.
That’s why it’s worth inspecting the entire roof rather than simply coating the area directly above the leak.
Can You Waterproof an Existing Shed Roof?
In many cases, yes.
If the roof structure itself is still sound, applying a waterproof coating can be considerably easier than stripping off the existing covering and replacing it.
A flexible liquid coating is particularly useful because it can create a continuous waterproof membrane across awkward shapes, joints and existing roofing materials.
S-FIXX FLEXICOAT is a water-based liquid rubber waterproofing coating designed to cure into a flexible protective membrane.
It can be used on a wide variety of suitable surfaces and is ideal for waterproofing jobs around the home and garden.
What You’ll Need:
Before starting, you’ll normally need:
- A stiff brush
- Suitable cleaning materials
- Paint brush or roller
- S-FIXX FLEXICOAT Liquid Rubber Waterproof Sealant
- Suitable gloves and protective clothing
- Materials to repair any major damage first
Always work safely when accessing a roof. If the shed roof cannot be reached safely, don’t attempt to climb onto it.
Step 1: Find the Leak
Start by inspecting the complete roof.
Look carefully for:
- Tears in roofing felt
- Cracks
- Holes
- Raised edges
- Failed seams
- Damage around screws or nails
- Areas where water collects
- Gaps around roof edges
Pay particular attention to joins and penetrations through the roof.
Even a very small opening can allow a surprising amount of water through during heavy rain.
Step 2: Clean the Roof
Preparation is one of the most important parts of any waterproofing job.
Remove loose dirt, moss, leaves and other debris using a stiff brush.
The surface should be clean and free from anything that could prevent the coating from bonding properly.
If the roof is wet, allow it to dry before applying the coating.
Don’t simply paint over moss or loose material. A waterproof coating is only as good as the surface underneath it.
Step 3: Repair Significant Damage
A liquid waterproof coating shouldn’t be used as a substitute for repairing serious structural damage.
Replace rotten timber and secure loose roof materials before applying the coating.
Larger holes, badly damaged sections or significant gaps may also require repair before waterproofing.
Once the underlying roof is sound, you can concentrate on creating the waterproof barrier.
Step 4: Pay Attention to Joints and Problem Areas
Before coating the main roof, inspect the areas most likely to leak.
These commonly include:
- Felt overlaps
- Roof edges
- Corners
- Fixings
- Flashing
- Previous repairs
Make sure the waterproof coating reaches properly into these areas.
One advantage of a liquid rubber coating is its ability to conform to irregular surfaces rather than relying on a pre-formed sheet.
Step 5: Apply S-FIXX FLEXICOAT
Once the roof is clean, sound and dry, S-FIXX FLEXICOAT can be applied using a brush or roller.
Work methodically across the roof and aim for even coverage.
FLEXICOAT starts as a liquid and cures to form a flexible rubber-like waterproof membrane.
This flexibility is particularly useful outdoors because roofing materials naturally expand and contract as temperatures change.
Rather than creating a rigid coating, FLEXICOAT is designed to remain flexible after curing.
Step 6: Allow the Coating to Cure
Don’t expose a freshly coated roof to water before the coating has had sufficient time to cure.
Weather conditions, temperature, humidity and coating thickness can all influence drying and curing times.
For best results, choose a suitable period of dry weather and always follow the application and curing instructions supplied with the product.
FLEXICOAT should be applied when the temperature is above 5°C.
Can FLEXICOAT Be Used on Roofing Felt?
FLEXICOAT can be used for many roof waterproofing and repair applications, including suitable existing roofing surfaces.
However, the condition of the existing roof is important.
Loose, badly deteriorated or unstable roofing material should be repaired or replaced first. The coating needs a sound surface to bond to.
If you’re uncertain about a particular surface, test a small inconspicuous area first.
Why Use Liquid Rubber on a Shed Roof?
Traditional roof repairs often involve cutting and fitting sheets of material.
Liquid rubber works differently.
Because it is applied as a liquid, it can follow the shape of the existing roof and create a continuous coating across joints and awkward areas.
Once cured, FLEXICOAT forms a flexible waterproof barrier.
That makes it useful for much more than sheds. FLEXICOAT can also be used for suitable waterproofing applications including:
- Roofs
- Gutters
- Ponds
- Foundations
- Planters
- Wood
- Concrete and masonry
Do You Need to Replace a Leaking Shed Roof?
Not necessarily.
If the timber structure is rotten, badly damaged or unsafe, replacement may be the correct solution.
But if the structure remains sound and the problem is deterioration of the waterproof surface, repairing and recoating the existing roof may extend its useful life without completely replacing it.
The important thing is to establish why the roof is leaking first.
Don’t cover serious structural problems and hope they disappear.
Repair the damage, prepare the surface correctly and then waterproof it.
How to Help Prevent Future Shed Roof Leaks
Inspecting your shed roof occasionally can help you catch small problems before they become major leaks.
Remove leaves and moss, keep gutters clear and check roof joints and edges after severe weather.
If you spot a small damaged area, dealing with it early is usually much easier than waiting until water has damaged the timber underneath.
Waterproof Your Shed Roof with S-FIXX FLEXICOAT
S-FIXX FLEXICOAT is a water-based liquid rubber waterproof sealant designed for DIY waterproofing and repair projects.
It can be applied using a brush or roller and cures to create a flexible waterproof membrane.
Available in 2 litre and 4 litre sizes, FLEXICOAT can be used for a wide variety of waterproofing jobs around the home and garden.
