Tar paper

B2B buyers must distinguish between #15 and #30 felt. #15 felt is suitable for standard residential roofing with steep slopes, while #30 felt is thicker, more tear-resistant, and recommended for heavy-duty applications, low-slope roofs, or as an underlayment for heavy materials like tile or slate. Ensure the GSM (Grams per Square Meter) aligns with your local building codes.

For the US market, ensure the product meets ASTM D226 (Type I or Type II) or ASTM D4869 standards. For European markets, look for CE marking and compliance with EN 13859-1. Always request Material Safety Data Sheets (MSDS) to verify the asphalt saturation levels and ensure the product is non-hazardous for transport and installation.

Prioritize suppliers that use high-quality organic wood pulp or fiberglass bases. The paper should be fully saturated with asphalt to ensure maximum water resistance. Check for UV stabilization if the underlayment will be exposed to sunlight for extended periods before the final roofing is installed. A high-quality tar paper should not curl, crack, or become brittle in extreme temperatures.

Traditional organic tar paper is cost-effective and provides a 'breathable' barrier that allows moisture to escape. However, synthetic underlayments (polyethylene/polypropylene) offer higher tear strength and lighter weight. For high-volume commercial sourcing, organic asphalt-saturated felt remains the industry standard for breathability and traditional shingle compatibility.

Tar paper is heavy and sensitive to heat. Ensure the supplier uses vertical palletization to prevent the rolls from flattening or 'telescoping.' During transit, containers can reach high temperatures; specify that the product must be stored in a cool, dry area and avoid 'top-loading' other heavy goods on top of the felt rolls to prevent core deformation.

When sourcing via Made-in-China.com, leverage Full Container Load (FCL) orders to reduce the high per-unit shipping cost caused by the product's weight. Negotiate based on tonnage or total square footage. Ask for a 5-10% discount on recurring annual contracts, and always verify if the price includes customized private labeling (OEM) for your brand.

Use secured payment terms and consider hiring a third-party inspection service (like SGS or Intertek) to perform a 'During Production Check' (DUPRO). This ensures the asphalt saturation ratio is consistent throughout the batch. Verify the supplier's Business License and Export Qualifications directly on their Made-in-China.com profile to mitigate fraud risks.

Check the HS Code (typically 4811.10) for your specific country to determine import tariffs. Be aware of anti-dumping duties that some regions impose on paper or asphalt-based products from specific origins. Work with a freight forwarder experienced in construction materials to ensure all Certificate of Origin documents are accurate to avoid costly customs delays.