"The WARDFLEX system described in this guide is intended primarily for interior use. See section 126.96.36.199 for specifics on outdoor applications. [That section speaks about connections to outdoor appliances.]
4.3.5 OUTDOOR ISSUES
WARDFLEX Mechanical Joint Fittings shall be protected from the effects of weather when used outdoors. After the connection is made to outdoor equipment the WARDFLEX Mechanical Joint Fitting shall be sealed by wrapping two layers of tape (e.g. PVC, Silicone) or by applying shrink sleeves (e.g. PVC, Polyolefin).
The following additional instructions regard the use of WARDFLEX in systems in which portions of the piping are exposed to the outdoors as required to make connections to gas meters or gas appliances,
which are attached to, mounted on, or located in close proximity to the building structure.
The external protective covering shall remain intact as much as practical for the given installation.
When installed along the side of a structure (between the ground and 6 ft.) in an exposed condition, the WARDFLEX must be protected inside a conduit or installed in a location which will not subject it to mechanical damage.
WARDFLEX shall not be buried directly in the ground or directly embedded in concrete (e.g. patio slabs, foundations or walk ways). When burial or embedment is required,WARDFLEX shall be routed inside nonmetallic (e.g.PVC) conduit. The conduit shall be sealed at any exposed end to prevent water from entering using double wrapped PVC tape or PVC shrink sleeves.