XR-5 Geomembrane Specifications
XR-5 is a reinforced geomembrane built from an ethylene interpolymer alloy (EIA) coating over a woven polyester base fabric. It is specified where hydrocarbon resistance, dimensional stability, and long exposed service govern: fuel storage secondary containment, exposed covers, and containment that ordinary polyethylenes or polypropylenes cannot serve.
Material properties and test methods
| Property | Test method | Published value |
|---|---|---|
| Construction | Visual / ASTM D751 | Ethylene interpolymer alloy coating over a woven polyester base fabric |
| Weight | ASTM D751 | 30 oz/yd2 nominal |
| Thickness | ASTM D751 | 30 mil nominal |
| Grab tensile strength | ASTM D751, grab method | 550 lb minimum, each direction |
| Tongue tear strength | ASTM D751 | 40 lb minimum, each direction |
| Hydrostatic resistance | ASTM D751, Method A | 800 psi minimum |
| Low temperature bend | ASTM D2136 | Pass at minus 30 F |
| Seam strength | Project specification | Heat-welded seams tested in shear and peel per the project specification |
| Characteristic | Reinforced EIA (XR-5 class) | Unreinforced HDPE / LLDPE |
|---|---|---|
| Strength source | Woven polyester scrim carries the load | Polymer sheet itself carries the load |
| Thermal expansion | Very low; panels lie flat through temperature swings | Higher; wrinkles are managed during placement |
| Elongation behavior | Low elongation, high dimensional stability | High elongation, conforms by stretching |
| Fabrication | Folds; shop-prefabricated into large panels | HDPE deploys from rolls and is field-welded panel by panel |
| Governing reference | Manufacturer-published data per ASTM D751 methods | GRI-GM13 (HDPE) and GRI-GM17 (LLDPE) |
What XR-5 is and when to specify EIA
XR-5 is a proprietary reinforced geomembrane: an ethylene interpolymer alloy coating calendered over a woven polyester base fabric. Unlike HDPE and LLDPE, which are governed by the generic GRI-GM13 and GM17 standards, XR-5 is specified against the manufacturer's published data sheet, with properties reported through the ASTM D751 family of coated-fabric test methods. The 30 oz/yd2 grade is the workhorse; heavier grades are published for higher-demand applications, and specifying engineers frequently call out sheet in the 30 to 45 mil range by application.
The material earns its specification in three situations: containment of fuels and aggressive liquids that attack polyolefins, exposed service where decades of UV and thermal cycling would work a high-expansion sheet loose, and geometry or schedule that rewards large prefabricated panels. Where none of those govern, commodity HDPE usually wins on material economics; where they do, EIA is often the only sheet on the approved-materials list.
Dimensional stability and exposed service
The woven polyester scrim gives XR-5 a very low coefficient of thermal expansion and low elongation under load, so panels lie flat through the daily temperature swing instead of growing the wrinkles installers manage on polyethylene jobs. On exposed containment, that flatness is not cosmetic: a liner that stays in intimate contact with the subgrade sheds stormwater cleanly, avoids wind uplift at bridged wrinkles, and keeps mechanical terminations from working loose over years of cycling.
EIA formulations carry a long published record in fully exposed service, including secondary containment in refineries and tank farms and exposed covers, without soil cover or coatings. For a submittal, the working rule is the same as any exposed material: the manufacturer's current data sheet, including its UV and weathering data, is the document of record, and it belongs in the package next to the project specification.
Chemical and fuel resistance
XR-5's defining application is hydrocarbon service. The manufacturer publishes immersion and compatibility data covering fuels including diesel and jet fuel, oils, and a broad range of industrial chemistry, which is why EIA appears in specifications for tank farm secondary containment, fuel-handling facilities, and military and utility fuel storage where a spill must be held for cleanup without the liner itself degrading.
As with every geomembrane, resistance belongs to the specific fluid, concentration, and temperature, not to the polymer family. The submittal step that prevents surprises is checking the actual containment chemistry against the manufacturer's chemical resistance chart, and requesting immersion test data for anything unusual. Where the chemistry is simple water or wastewater, XR-5 still performs, but less costly materials usually serve.
Prefabrication and field installation
XR-5 folds without damage, so fabrication shops weld factory rolls into large one-piece panels, test the seams on the bench, and ship the panel folded on a pallet. Field crews unfold panels into place and close a small number of field seams by heat welding, then vacuum test the field seams. On tank ring walls, sumps, and structure-heavy containments, the panel approach moves most of the seaming into controlled conditions and shortens the on-site window.
Terminations are where reinforced materials shine: the scrim carries load into batten bars and mechanical attachments without the sheet necking down. Our crews have installed 45 mil XR-5 with stainless steel mechanical attachments on fuel storage containment and large biogas cover work, including installations where every seam was vacuum tested and the completed system was smoke tested for leaks. That combination of prefabricated panels, welded details, and verified seams is the standard playbook for EIA installation.
What appears on an XR-5 submittal
An XR-5 submittal is built around the manufacturer's current product data sheet: base fabric and coating description, weight and thickness per ASTM D751, grab tensile and tongue tear per ASTM D751, hydrostatic resistance per ASTM D751 Method A, low temperature performance per ASTM D2136, and the weathering and chemical resistance data relevant to the application. Because the material is proprietary, the data sheet does the work a GRI standard does for polyethylene, so its revision date matters.
The installation half of the package covers the fabrication shop's panel drawings and factory seam records, field seaming procedures and welder qualifications, the seam testing plan with vacuum testing of field seams and destructive shear and peel testing at the specified frequency, and details for mechanical terminations and penetrations. On fuel containment work, expect the reviewing engineer to also ask for the chemical compatibility confirmation in writing.
We install this material
Tank and facility containment, prefabricated drop-in or full field installs.
Frequently asked questions
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