When and Why You Need to Refelt Your Shed Roof
The roof of your garden shed is its primary defence against the elements. Over time, exposure to sun, rain, frost, and wind can degrade the roofing felt, leading to leaks, rot, and a compromised structure. Recognizing the signs of wear and understanding when it's time to refelt your shed roof is crucial for preserving its longevity and protecting its contents. Typical indicators include cracking, bubbling, peeling, or visible tears in the existing felt, especially around edges and seams. If water is pooling or you're noticing damp patches inside the shed, a prompt refelt is likely necessary.
Choosing to refelt rather than replace the entire roof is often a more economical and straightforward solution, provided the underlying roof structure (the timber boards) is sound. This process involves stripping away the old, damaged felt and applying a fresh layer or layers of new roofing felt. It's a rewarding DIY project that can significantly extend the life of your garden building, preventing more extensive and costly repairs down the line. The aim is to create a watertight, durable seal that can withstand varying weather conditions for years to come.
- Assess shed roof for cracks, bubbles, or tears.
- Refelting is more economical than full roof replacement.
- Ensure underlying roof structure is sound before refelting.
- A new felt layer protects against water damage and rot.
Understanding Different Roofing Felt Types
The market offers several types of roofing felt, each with its own characteristics and suitability for different applications. The most common is traditional bitumen felt, often referred to as shed felt. This is typically fibre-based, impregnated and coated with bitumen, and surfaced with mineral granules for UV protection. It's relatively inexpensive and straightforward to install, making it a popular choice for standard garden sheds.
For enhanced durability and longevity, consider polyester-reinforced bitumen felt. This type incorporates a strong polyester base mat, offering superior tensile strength and resistance to tearing compared to standard felt. It's a good option for larger sheds or those in exposed locations. High-performance felts, often based on SBS (styrene-butadiene-styrene) modified bitumen, provide greater flexibility, improved weather resistance, and a longer service life, though they typically come at a higher cost. When selecting your felt, consider the size of your shed, its exposure to weather, your budget, and the desired lifespan of the repair.
Preparation is Key
Before you can begin applying new felt, thorough preparation of the shed roof deck is vital. Begin by safely removing all existing roofing felt. Use a stiff brush or scraper to clean away any old adhesive, debris, or loose material. Inspect the timber boards underneath for any signs of rot or damage. If you discover rotten wood, it's essential to replace these sections before proceeding, as new felt applied over a compromised base will inevitably fail.
Ensure the roof deck is clean, dry, and smooth. Any protruding nails or staples should be hammered flat or removed. If the existing boards are uneven, consider adding a layer of thin plywood or OSB board over the top to create a uniform surface for the new felt. This step is critical for achieving a neat finish and preventing the new felt from being punctured or stressed by uneven surfaces. A well-prepared base ensures the new felt adheres correctly and performs optimally.
Materials and Tools for Refelting a Shed Roof
To successfully refelt your shed roof, gathering the correct materials and tools beforehand will streamline the process. The primary material is, of course, your chosen roofing felt. You'll need enough to cover the entire roof area, plus a generous overlap for the edges and ridge. It's always advisable to purchase slightly more than your calculated roof area to account for waste and ensure complete coverage. Many standard sheds require a roll of around 10 metres.
You will also need appropriate fixings. For bitumen felt, clout nails (large-headed roofing nails) are standard. These should be corrosion-resistant, such as galvanized steel. You'll also require a good quality, cold-applied roofing felt adhesive or bitumen-based lap cement, which is essential for sealing the overlaps and edges securely, preventing water ingress. Consider a felt lap sealant for extra protection on seams.
Essential Tools for the Job
A sharp utility knife or felt cutter is indispensable for trimming the felt accurately to size. A heavy-duty staple gun can be useful for temporarily securing the felt before nailing or for specific detailing, though it's often recommended to use the adhesive and nails for the main structure. A measuring tape and a chalk line or spirit level will help ensure straight cuts and accurate placement. You'll also need a stiff brush or broom for cleaning the roof deck, a claw hammer for removing old nails, and potentially a trowel or spreader for applying the adhesive evenly.
Safety equipment is paramount. Wear sturdy work gloves to protect your hands from rough materials and sharp edges, and safety glasses to shield your eyes from debris. If working at height, even on a low-pitched shed roof, consider using a stable ladder and securing it properly. A dust mask might be beneficial if there's a lot of old felt debris to clear. Having all these items ready will make the refelting process much more efficient and safe.
The Method: How to Apply Shed Roofing Felt
Applying new shed roofing felt requires careful attention to detail to ensure a watertight finish. Begin by unfurling the first length of felt along the eaves (the lower edge of the roof) with a generous overhang. This overhang should typically be around 50-75mm, which will be turned down over the fascia board or edge to prevent water running underneath. Apply a bead of adhesive along the eave and carefully press the felt into it, securing it firmly.
Proceed to apply the felt up the slope towards the ridge. Use the adhesive generously along the edges of the roof deck where the felt will be secured. For a strong bond, it's recommended to apply adhesive to both the roof deck and the underside of the felt where it will meet. Unroll the felt gradually, smoothing it down as you go to avoid creases and air bubbles. Use clout nails at intervals of approximately 50-100mm along the edge, ensuring they are driven straight and flush with the felt surface. The key is to create a continuous, well-adhered surface.
Layering and Overlapping
The technique for overlapping felt is crucial for preventing leaks. For a standard single-layer application, the second and subsequent strips of felt should overlap the previous one by at least 100-150mm. This overlap should run in the direction of the prevailing wind and water run-off, typically from the eaves upwards to the ridge. Apply adhesive generously to the underside of the overlapping strip and press it down firmly onto the strip below. The top edge of the felt at the ridge should overlap the felt coming up from the opposite side by a similar margin, ensuring the highest point is sealed.
If your shed roof is particularly large or has a significant pitch, you might consider a double-layer application for added protection. This involves laying a base layer, then a top layer over it with staggered or offset seams. Always ensure that any fixings (nails) are adequately covered by the subsequent layer of felt or by sealant to prevent water from seeping through the nail holes. Pay particular attention to corners and edges, folding the felt neatly and securing it with adhesive and nails to create a robust barrier.
Finishing Touches and Sealing
Once the main roof area is covered, it's time for the finishing touches. Trim any excess felt neatly along the sides and at the ridge, leaving a slight overhang if required for a clean edge. Fold the overhangs at the eaves down over the fascia and secure them with adhesive and clout nails. At the ridge, ensure the top layer of felt completely covers the join and is well-adhered. For a superior seal, apply a bead of felt lap sealant along all exposed seams, overlaps, and edges where the felt meets any vertical surfaces or capping.
This sealant helps to protect the most vulnerable areas from water ingress and UV damage, extending the life of your new felt roof. Allow the adhesive and sealant to cure fully according to the manufacturer's instructions before exposing the roof to heavy rain. A properly refelted roof not only keeps your shed dry but also enhances its visual appeal, making it look more robust and well-maintained. Consider applying a protective coating or paint specifically designed for shed felt after it has fully weathered, which can further prolong its lifespan and add a touch of colour to your garden.
Alternatives and Maintenance for Shed Roofs
While refelting with bitumen-based materials is the most common approach, several alternatives exist for shed roofing, offering different aesthetic qualities, durability, and price points. For a more premium and longer-lasting finish, consider EPDM (ethylene propylene diene terpolymer) rubber roofing. EPDM is a single-ply membrane that is highly durable, flexible, and resistant to UV rays and extreme temperatures. It's often applied using a special adhesive and can last for 20-30 years or more, making it a significant upgrade from traditional felt. It's ideal for modern-looking sheds or garden rooms.
Another option is cedar shingles or shakes, which provide a natural, attractive appearance and good insulation properties. While more expensive and requiring more intricate installation than felt, they offer a beautiful, traditional look that ages gracefully. For a very budget-conscious approach, some may consider corrugated plastic or metal sheeting, though these can be noisy in rain and may not offer the same aesthetic appeal as felt or EPDM. When choosing, weigh the initial cost against the expected lifespan, maintenance requirements, and the desired visual impact for your garden space.
Maintaining Your New Shed Roof
Once you've successfully refelted your shed roof, regular maintenance is key to ensuring its longevity. Periodically, perhaps once or twice a year, inspect the roof for any signs of damage, such as lifting edges, punctures, or debris accumulation. Clear away any fallen leaves, moss, or other organic matter, as these can trap moisture and lead to premature deterioration of the felt or underlying structure. Ensure that water is draining away effectively and not pooling on the surface.
Check that the sealant around the edges and seams remains intact. If you notice any cracks or gaps, reapply felt lap sealant to maintain the waterproof barrier. For bitumen felt roofs, applying a specialized protective coating or acrylic paint designed for shed roofing can add an extra layer of UV protection and weather resistance. This not only preserves the felt but can also refresh the look of your shed. Proper maintenance will help you avoid the need for refelting again for many years.