Serving two distinct purposes with the option of either perforated (3800P) or solid (3800S), rFOIL 3800 Reflective Radiant Barrier is either a revolutionary next generation house wrap or an effective vapor barrier.Serving as a Reflective House Wrap, perforated 3800P offers the construction industry a strong weather-resistant barrier with the added benefit of a Radiant Barrier, a tested R-3.8 value (ASHRAE Handbook: 1997 Fundamentals), and a Perm. Rating of 22. rFOIL 3800 REFLECTIVE VAPOR BARRIER 3800P has been referenced as “the next generation in house wrap technology”. Acting not only as a superior air infiltration barrier, effectively sealing up cracks or gaps in the external sheathing, but also as a protective radiant barrier to the exterior of the home blocking up to 97% of radiant heat resulting in better year-round efficiency and comfort levels. Unlike other house wraps or insulating products that are traditionally used, rFOIL Reflective Radiant Barrier is non-toxic and its performance is not affected by extended exposure to the elements. rFOIL 3800 Reflective Radiant Barrier is constructed of a single layer of 99.9% pure aluminum foil laminated to a formulated blend of polyethylene. 3800P is pin perforated; 3800S is not. Solid 3800S serves as a vapor barrier. rFOIL 3800 REFLECTIVE VAPOR BARRIER is constructed of a single layer of 99.9% pure aluminum foil laminated to a formulated blend of polyethylene. 3800P is pin perforated; 3800S is not.