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Backflow Protection
Backflow Cages & Enclosures
Commercial-grade backflow cages and covers that protect backflow preventers from theft, vandalism, and weather — powder-coated steel cages, locking enclosures, and insulated covers for every assembly.
A backflow cage or cover protects a valuable backflow preventer from vandalism, theft of its copper and brass, and freezing weather. This collection carries commercial-grade backflow cages in a range of sizes, plus powder-coated and stainless steel covers, with lift-off and locking designs for easy testing and maintenance. Every backflow cage and cover on this page ships free.
Need a fully insulated, heated enclosure?
See the full StrongBox aluminum and stainless steel backflow enclosure lineup.
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Understanding Backflow Covers, Cages & Enclosures
A backflow cover protects your backflow preventer from two things: the weather and people. When the weather turns, a cover keeps rain, snow, and freezing temperatures off the assembly; year-round, it stops thieves from stripping the valuable copper and brass and deters vandals. As long as the preventer is covered, it's protected.
The right choice depends on how much protection you need — from a simple insulated bag to a powder-coated backflow cage to a fully heated aluminum enclosure. The guide below breaks down every type by protection level, size, color, and price range so you can make an informed decision.
Backflow Enclosure Types at a Glance
Six common ways to protect a backflow preventer, from lowest to highest protection. "Frost" means insulation only; "freeze" means a positive heat source for hard freezes.
| Type | Theft / Vandal | Freeze Protection | Price Range |
|---|---|---|---|
| Blanket / Bag | None | R-13 insulation (frost) | $10–$50 |
| Cage | Locking, powder-coated steel | None (add a bag) | $300–$1,000+ |
| Fake Rock | Conceals, no lock | R-8 insulation, some heated | $30–$3,000 |
| Plastic | Conceals, no lock | Bag or heated (most frost only) | $200–$650+ |
| Fiberglass | Locking shelter | Spray foam + wall heater | $300–$6,000+ |
| Aluminum | Locking, marine-grade | R-9 + slab-mounted heater | $500–$10,000+ |
Cages, fake rocks, and plastic covers are generally sold for backflow assemblies 2 inches or smaller. Aluminum and fiberglass enclosures cover the full size range.
A Complete Guide to Backflow Covers
Cage
Backflow Cage
Powder-coated steel with a locking mechanism — solid theft, vandal, and accident protection. No insulation, so use above 33°F or pair with an insulated bag. Typically 24"×24" up to 60"×60", green or tan, roughly $300–$1,000+.
Aluminum
Aluminum Enclosure
Marine-grade aluminum with locking mechanisms, R-9 polyisocyanurate insulation, and an optional slab-mounted heater that protects both the shelter pipes and the riser pipes below. Wide size range, several colors, ~$500–$10,000+.
Fiberglass
Fiberglass Enclosure
Locking fiberglass shelter with spray-foam insulation and an optional wall-mounted heater. Durable, though the surface can suffer UV fiber bloom and cracking over time. ~$300–$6,000+.
Blanket / Bag
Insulated Bag
R-13 thermal insulation for frost protection on the pipes — but no protection against theft or vandalism. Sold alongside a cage, rock, or plastic cover. 24"×24" to 60"×60", ~$10–$50.
Fake Rock
Fake Rock Cover
Blends into the landscape and conceals the assembly, with R-8 insulation (some heated). No locking mechanism; interiors taper, so confirm interior clearance. For assemblies 2" and smaller. ~$30–$3,000.
Plastic
Plastic Cover
Lightweight cover for theft and vandal deterrence; most offer frost protection only via an insulated bag, not hard-freeze protection. No lock. For preventers 2" and smaller and PVBs. ~$200–$650+.
Backflow Cage vs. Enclosure
The core difference is freeze protection. A backflow cage is powder-coated steel with a lock — it deters theft and vandalism and shields against accidents, but it has no insulation, so it should only be used where temperatures stay above freezing (or paired with an insulated bag). A backflow enclosure adds insulation and, in aluminum and fiberglass models, a heater — protecting the assembly through hard winter freezes as well as theft.
If your backflow preventer is installed outdoors in a cold-weather climate, an insulated or heated enclosure is the safer long-term choice. In mild climates where the goal is theft and vandal protection, a cage or a cage plus an insulated bag is often all you need. Either way, if it's worth protecting, it's worth protecting the right way.
Backflow Cage & Cover FAQ
What is a backflow cage?
A backflow cage is a powder-coated steel enclosure with a locking mechanism that protects a backflow preventer from theft, vandalism, and accidental damage. Cages don't include insulation, so in freezing climates they're used with an insulated bag or replaced by a heated enclosure.
What is the difference between a backflow cage and a backflow enclosure?
A cage provides security (theft and vandal protection) but no freeze protection. An enclosure — aluminum or fiberglass — adds insulation and often a heater, protecting the assembly through hard freezes in addition to security. Choose a cage in mild climates and an insulated or heated enclosure where it gets cold.
Do I need a backflow cover?
If your backflow preventer is installed above ground outdoors, a cover is strongly recommended. It protects against freeze damage in cold climates and against theft of the copper and brass, plus rain, wind, and impact. A covered preventer is far safer than an exposed one.
How do I size a backflow cage or cover?
Measure the full installed assembly — length, width, and height including valves and test cocks — and add clearance for testing and service. Note that fake-rock and tapered covers have interior dimensions that narrow toward the top, so confirm interior clearance. Cages, rocks, and plastic covers are usually for assemblies 2 inches and smaller; aluminum and fiberglass cover larger sizes.
Does everything on this page ship free?
Yes. Every backflow cage, cover, and enclosure on this page ships free on all orders. For volume pricing on larger quantities, use the quote request page for a written quote.