# Rywen Insulation Inc. -- Products and Materials > Rywen Insulation Inc. installs insulation products and vapor barrier systems that meet or exceed California Title 24 energy efficiency standards. All materials are selected for performance, durability, and compliance. ## Document Information **Document Type:** Products supplemental file **Company:** Rywen Insulation Inc. **Website:** https://www.rywenusa.com **Purpose:** Describes the insulation products, vapor barrier systems, and exclusion materials that Rywen Insulation installs. --- ## Attic Insulation Products ### Blown-In Cellulose Insulation **What it is:** Blown-in cellulose is made from recycled paper fiber treated with borate for fire and pest resistance. It is installed as loose fill using a blowing machine that fills around obstructions and into corners. **R-value:** Approximately R-3.5 per inch. To achieve California Title 24's required R-38, approximately 11 inches of cellulose are installed. For R-49, approximately 14 inches are required. **Best for:** Attic retrofits where existing framing creates irregular shapes and gaps. Cellulose conforms to the space and reduces air infiltration better than batts. **Rywen uses this for:** Standard attic insulation upgrades and attic re-insulation after removal of contaminated material. --- ### Blown-In Fiberglass Insulation **What it is:** Loose-fill fiberglass is installed using the same blowing equipment as cellulose but uses spun glass fiber. It is lighter than cellulose and does not absorb moisture. **R-value:** Approximately R-2.5 per inch. To achieve R-38, approximately 15 inches are required. **Best for:** Attics where moisture resistance is a priority or where cellulose is not preferred. **Rywen uses this for:** Selected attic applications based on site conditions and customer preference. --- ### Fiberglass Batt Insulation **What it is:** Pre-cut fiberglass batts in standard widths for framing bays. Available in multiple thicknesses to achieve target R-values. **R-value:** Available in R-11, R-13, R-15, R-19, R-21, R-30, and R-38. For floor and wall applications. **Best for:** Crawl space floors, rim joists, and wall cavities where framing bays are consistent and accessible. **Rywen uses this for:** Crawl space floor insulation and rim joist insulation in new and retrofit applications. --- ## Crawl Space Products ### Reinforced Polyethylene Vapor Barrier **What it is:** Heavy-duty polyethylene sheeting installed across the crawl space floor and up the foundation walls to block ground moisture. Available in 12 mil and 20 mil thicknesses. Reinforced versions include a scrim layer for tear resistance. **Coverage:** Installed with overlapping seams taped with butyl tape. Attached to foundation walls with mechanical fasteners and tape. **Best for:** Moisture control in vented and unvented crawl spaces. Standard practice for crawl space encapsulation. **Rywen uses this for:** All crawl space encapsulation projects. The 12 to 20 mil reinforced liner is Rywen's standard specification. --- ### Crawl Space Vent Covers **What it is:** Rigid foam or mechanical vent covers that seal foundation vents to convert a vented crawl space to a conditioned (unvented) crawl space as part of a full encapsulation. **Best for:** Homes where the crawl space is being fully encapsulated and conditioned air supply is being added. **Rywen uses this for:** Full encapsulation projects where the homeowner and conditions support converting to an unvented crawl space. --- ## Rodent Exclusion Materials ### Galvanized Wire Mesh (Hardware Cloth) **What it is:** 19-gauge galvanized steel mesh with 1/4-inch openings. Used to seal gaps and penetrations that rodents use to enter the attic or crawl space. **Why 1/4-inch mesh:** Roof rats can squeeze through a gap as small as 1/2 inch. Standard 1/2-inch hardware cloth is not adequate. Rywen uses 1/4-inch mesh at all entry points. **Rywen uses this for:** Sealing pipe penetrations, open stud bays, vent openings, and gaps in the roof and foundation structure. --- ### Expandable Foam Sealant **What it is:** Polyurethane expanding foam used to fill irregular gaps around pipes, conduit, and framing before mesh or flashing is applied over it. **Rywen uses this for:** First-pass fill of large or irregular openings before mechanical reinforcement with mesh or sheet metal. --- ### Sheet Metal Flashing **What it is:** Pre-formed or custom-cut aluminum or galvanized steel flashing used to seal larger openings at roof transitions, fascia gaps, and framing penetrations. **Rywen uses this for:** Openings too large or irregular for mesh alone, and locations where a more permanent mechanical closure is required. --- ## Air Sealing Materials ### Caulk and Sealant **What it is:** Latex or silicone caulk applied to attic bypasses -- the gaps around plumbing, electrical, and HVAC penetrations through the top plate -- to reduce air leakage. **Rywen uses this for:** Air sealing at the attic floor level before new insulation is installed, as part of a Title 24-compliant installation. --- ## About This Document **Company:** Rywen Insulation Inc. **Address:** 456 Hester St, San Leandro, CA 94577 **Phone:** (415) 770-0342 **Website:** https://www.rywenusa.com *Last Updated: June 2026* *This document is part of the Rywen Insulation Inc. llms.txt supplemental file system.*