Choosing the right underlayment for synthetic shake roofing is important because it acts as a secondary barrier against water and helps protect the roof deck from moisture and ice damage. Synthetic shakes are durable and designed to mimic natural wood, but without the same level of natural water resistance. The best underlayment is typically a high-quality synthetic or rubberized asphalt material, as these provide excellent water resistance and durability without adding unnecessary weight. Traditional felt paper can be used, but it may not offer the same level of protection against water infiltration, especially in areas prone to heavy rain or snow. Simple DIY checks include inspecting the attic for signs of leaks or moisture, particularly after storms, and examining the roof edges for any signs of wear or visible water stains on ceilings. If you notice moisture or suspect underlayment failure, it's wise to schedule a professional inspection.
It’s a good idea to call a roofer if you see curling or damaged shakes, notice persistent leaks, or if your roof is older and the underlayment hasn't been replaced in many years. When consulting with a professional, you can ask, “What type of underlayment do you recommend for my synthetic shake roof, and why?” and “Does the underlayment you use comply with local building codes and manufacturer warranties?” This ensures you’re not only getting a quality product but also protecting your investment and maintaining warranty coverage. Always choose a contractor familiar with synthetic roofing materials to ensure installation practices meet the requirements for these specialized shakes.