The shed roof is a crucial weather barrier for protecting stored tools, equipment, and supplies. Fitting or re-felting a shed roof extends its life, improves waterproofing, and can be a cost-effective DIY project. This guide covers materials, preparation, steps, safety tips, and maintenance to help homeowners in the United States achieve a durable, long-lasting roof felt installation that withstands seasonal rain, sun, and temperature shifts.
Preparation And Planning
Before starting, inspect the roof deck for damage, rot, or loose boards. Replace any compromised sections and ensure the structure is solid. Measure the roof area to calculate the amount of felt and underlayment required, adding 10% extra for waste. Choose the right type of felt, typically 15 lb or 30 lb asphalt-saturated felt for sheds, or synthetic underlayment for enhanced durability. Gather safety gear, including gloves, eye protection, a sturdy ladder, and a partner to assist with lifting and handling. Weather conditions matter; plan for a dry, calm day to ensure proper adhesion and curing of the felt.
Materials And Tools
Quality materials make a big difference in performance and longevity. Key items include:
- Roofing felt: asphalt-saturated felt or synthetic underlayment designed for sheds
- Roofing nails or cap nails with plastic washers
- Hammer or nail gun suitable for roofing nails
- Roofing cement or seam sealant for edges and joints
- Roof deck primer or bituminous adhesive (if using self-adhesive underlayment)
- Underlayment optional layer for added waterproofing (in areas with heavy rainfall)
- Chalk line and straightedge for straight alignment
- Scissors or utility knife for cutting felt
- Broom or blower to clean the deck
For best results, choose a UV-resistant underlayment and compatible fasteners that prevent rust and corrosion. If the shed has short spans or irregular angles, synthetic felt can offer superior tear resistance and wind uplift performance.
Step-By-Step Installation
Follow a systematic approach to ensure a tight, water-shedding surface. Each paragraph keeps the work sections concise and actionable.
Step 1: Prepare The Deck Clear debris, sweep the surface, and repair any damaged boards. Allow the deck to dry completely. If there is existing tar paper or old felt, remove it to ensure clean adhesion for the new layer.
Step 2: Install The Starter Strips Start at the bottom edge, placing a starter strip along the eave. Align the edge with the outer line of the roof and leave a slight overhang. Nail into place every 6 to 8 inches, ensuring flat, wrinkle-free placement. This edge will guide subsequent rows.
Step 3: Lay The Felt Roll out the felt horizontally across the roof, overlapping each row by 2 to 4 inches to shed water properly. For underlayment, begin at the bottom and work upward. Smooth out any bubbles or wrinkles as you go to prevent air pockets that can leak later.
Step 4: Secure The Rows Fasten the felt with roofing nails, placing them about 6 to 8 inches apart along each strip. Use a hammer or nail gun to drive nails through the felt into the deck, maintaining a consistent spacing. Leave a slight overhang at the edge to prevent wind-driven water infiltration.
Step 5: Overlap And Seal Ensure each subsequent row overlaps the preceding one adequately. Apply seam sealant or roofing cement along the overlaps and at the edges to create a continuous barrier. If using self-adhesive felt, peel away the protective film and press firmly to seal, using a hand roller to ensure full adhesion.
Step 6: Edge Finishing Trim excess felt at the ridge and eaves with a utility knife. Install drip edge or fascia flashing as needed to direct runoff away from the shed walls. Inspect all seams and corners, adding additional sealant where necessary.
Step 7: Final Inspection Check for loose nails, wrinkles, or gaps. Tighten nails, resecure any loose sections, and ensure the entire surface is watertight. Clean tools and dispose of waste responsibly.
Common Issues And Solutions
Felt installations can encounter issues if not properly prepared or executed. Common problems include wrinkles, misaligned overlaps, and lift from high winds. Wrinkles can be reduced by pulling the felt taut as it is laid and avoiding overstretching, which can cause future tears. If edges lift, reseal with appropriate sealant or replace a small section. In windy climates, consider adding extra fasteners and a wind uplift test on a small area to verify hold. For extreme sun exposure, synthetic underlayment offers better resistance to UV degradation and should be considered for longevity.
Maintenance And Longevity
Regular checks extend the life of a felt shed roof. Inspect after heavy storms or seasonal changes for signs of wear, tears, or water staining. Promptly repair damaged areas with fresh felt and sealant. Cleaning the roof periodically removes leaves and debris that can trap moisture. Consider a UV-protective coating or a higher-grade synthetic underlayment in areas with intense sun or frequent rainfall. Re-felting intervals vary but typically range from 5 to 15 years depending on climate, quality of materials, and installation precision.
Cost, Time, And Practical Considerations
The cost to felt a shed roof includes materials, nails, sealant, and any necessary underlayment. A typical 8×10 shed roof might require 1 to 2 rolls of felt and a modest amount of sealant, with total costs ranging from $150 to $350 depending on material quality and local prices. DIY installation can take a weekend for a standard shed, less if the deck is prepped and weather is favorable. Hiring a pro adds labor costs but offers professional adjustments for wind-prone areas. Always factor safety gear, time for drying and curing, and proper disposal of old materials into the budget.