When Time and Tar Paper Tango: A Dance with Roofing Felt

Roofing felt, a common sight on construction sites, often cloaks the skeletal framework of a roof before the final exterior layer is added. Its purpose is more than just cosmetic. It plays a pivotal role in protecting homes from the elements, acting as a waterproof barrier and stabilizing surface for the exterior roof covering. But a question often arises: how long can roofing felt stay exposed?

The Role of Roofing Felt

Roofing felt, or ‘tar paper’ as it’s colloquially known, is a crucial component of modern roofing systems. It’s an asphalt-saturated material placed over the roof decking and beneath the final exterior covering. It’s like a secret agent, quietly performing several essential functions:

  • It acts as a water-resistant barrier, helping to prevent leaks from getting to the roof deck.
  • It reduces friction between the roof and the exterior covering, allowing materials to expand and contract with temperature changes.
  • It adds stability, smoothing over inconsistencies in the roof decking to provide a uniform surface for the exterior layer.
  • It endures high winds battering, providing extra hold against potential wind damage.
  • It also offers some insulation, reducing heat transfer and energy costs.

The Exposure Dilemma

Although roofing felt is designed to be hidden beneath other materials, it’s often exposed temporarily during roof construction or repair. The safe exposure time varies depending on several factors, but there are general guidelines:

  • Most roofing felt products can withstand exposure for 1-2 weeks without significant issues.
  • Some premium or specialized felts have warranties that cover up to 90 days of exposure.
  • However, no roofing felt products are designed to function indefinitely as a finished roof surface.

Exceeding these exposure limits can cause problems such as brittleness and cracking due to sun damage, loss of water resistance as coatings wear away, and possible interior water damage because of leaks.

Factors Influencing Exposure Time

Certain conditions can accelerate the deterioration of exposed roofing felt and shorten the safe exposure duration. These include:

  • Hot climates can soften the asphalt coatings and cause the materials to dry out faster.
  • High levels of sun exposure, particularly on the south- or west-facing roofs.
  • Wet and windy conditions can stress the felt and erode protective coatings.
  • Improper installation techniques leave them feeling vulnerable.
  • Use of low-quality felts, which are more susceptible to rapid degradation.
  • Steeply sloped roofs can cause the felt to slide or lift off before the exterior covering is installed.

Keeping it Covered

If the roofing felt needs to remain exposed longer than recommended, it’s advisable to take measures to protect it. These might include covering the felt with waterproof tarps or plastic sheeting between work sessions, weighting down loose edges to prevent wind uplift, or applying extra waterproofing layers. It’s also essential to limit foot traffic on the exposed felt and to avoid dragging tools over its surface.

For the most accurate exposure guidelines, consult the manufacturer’s specifications for the particular roofing felt product. Different materials and coatings can offer varying degrees of temporary exposure resistance. Remember, it’s always better to cover or protect exposed felt immediately to avoid compromising the roof’s integrity.

Wrapping Up the Roofing Riddle

In essence, roofing felt, though often unseen, plays a vital role in the longevity and stability of your home’s roof. It’s designed to be a temporary underlayment and is not intended to withstand the elements indefinitely. So, if you’re wondering how long can roofing felt stay exposed, the answer will depend on the specific product and conditions, but generally, it should not remain uncovered for more than a few weeks. After all, it’s not about giving your roof a stylish hat; it’s about ensuring it has a reliable helmet.

Jamie Verve
Jamie Verve
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