Roofing felt plays a vital role in protecting your roof from water infiltration, extending its durability, and providing a secure underlayment for shingles or tiles. Ensuring the roofing felt is installed at the correct tension is crucial for its effectiveness. So, how tight should roofing felt be? Let’s explore this important question.
1. The Ideal Tightness for Roofing Felt
Roofing felt should be laid flat and securely fastened, but not overly stretched. Striking the right balance between tension and flexibility ensures the felt remains effective. Here’s what to aim for:
- Flat Without Wrinkles: The felt should lie smoothly without any wrinkles or bubbles, as these can compromise the waterproofing and make it harder to apply shingles or tiles evenly.
- No Overstretching: Avoid pulling the felt too tight, as overstretching can cause it to tear or shift, particularly during temperature changes or high winds.
2. Why Proper Tension Matters
Laying roofing felt with the correct tension provides several benefits:
- Waterproofing: A smooth, well-fitted felt layer prevents water from pooling or seeping into the roof deck.
- Longevity: Felt that isn’t too tight or loose is less likely to tear or degrade over time.
- Structural Stability: Proper tension ensures the felt stays securely in place, even during strong winds or heavy rainfall.
3. Steps for Achieving Proper Tightness
Follow these steps to ensure your roofing felt is installed at the right tightness:
- Start at the Bottom Edge:
Begin at the lowest point of the roof, aligning the felt with the edge. Secure it with nails or staples spaced every 6-8 inches along the edges. - Roll the Felt Smoothly:
Unroll the felt gradually, smoothing it out as you go. This prevents wrinkles or bubbles from forming. - Secure the Felt Without Stretching:
Fasten the felt securely, but avoid pulling it too tightly. Let the material rest naturally to accommodate any expansion or contraction caused by temperature changes. - Overlap Correctly:
Overlap each strip by at least 20cm (200mm) to ensure a watertight seal. Make sure overlaps are smooth and flat. - Inspect for Wrinkles:
After securing each section, inspect for wrinkles or sagging. If adjustments are needed, loosen and reposition the felt before proceeding.
4. Common Mistakes to Avoid
- Overstretching: This can cause tears or weak spots in the felt, reducing its durability.
- Loose Installation: Felt that is too loose may wrinkle or sag, compromising its waterproofing and making it more vulnerable to wind damage.
- Ignoring Overlaps: Improper overlaps can lead to water seepage, even if the felt is laid at the correct tension.
5. Additional Tips for a Professional Finish
- Use Adhesive: For extra security, especially on flat roofs, apply roofing adhesive along the edges and overlaps to hold the felt in place.
- Check Weather Conditions: Install roofing felt on a dry, calm day to prevent wind or moisture from interfering with the process.
- Teamwork Helps: Having an extra pair of hands to unroll and secure the felt ensures better control over the tension.
Roofing felt should be installed flat and secure, but not overly tight. Proper tension allows the felt to function as an effective barrier against water, while also accommodating natural movement due to temperature changes. Avoid overstretching or leaving the felt too loose, and always check for a smooth finish to ensure your roof remains protected and durable for years to come. By following these guidelines, you can achieve a professional-quality installation and peace of mind.
