Repiping a Florida Home: PEX vs. Copper

Why Repiping Comes Up So Often in Southwest Florida

A lot of homes in Lee, Charlotte and Collier Counties went up during building booms that used materials we now replace. Polybutylene was installed in homes from 1978 into the mid-1990s, and plenty of it is still hiding in walls and ceilings around Fort Myers, Port Charlotte and Naples. Older copper systems are a second group. Some of them have started springing pinhole leaks after decades of service.

Then there’s insurance. Florida carriers commonly ask for a 4-point inspection on older homes, and the plumbing section of that report can decide whether a policy gets written. So many repipe conversations start with an underwriter’s letter rather than a leak.

This guide compares the materials we see used for a full repipe today: PEX, copper and CPVC. If you already know you need the work done and want to see how we handle it, our whole-house repiping page walks through the process. Here we focus on choosing the pipe.

PEX Basics: What the Letters Mean

PEX is cross-linked polyethylene. Cross-linking ties the plastic’s molecules together so the pipe holds up to hot water and pressure. The letter after PEX tells you how that cross-linking was done, and it changes how the pipe behaves on the job and later.

PEX-A

PEX-A is made with the peroxide (Engel) method, where cross-linking happens during extrusion. It typically reaches a higher degree of cross-linking, around 80 to 85 percent. In practice that makes it the most flexible type. It bends tighter around framing, and it has thermal memory: if a run gets kinked, the kink can usually be reshaped with a heat gun instead of cut out.

PEX-B

PEX-B uses the silane, or moisture-cure, method after extrusion and lands lower on cross-linking, roughly 65 to 70 percent. It’s stiffer and needs a wider bend radius. A kink in PEX-B gets cut out and repaired with fittings. It costs less to make, and the tooling for it is cheaper, which is why you see it in a lot of hardware store aisles.

Both types are rated for potable hot and cold water and both last when installed right. The real difference is in handling and in the fittings each one is designed for.

Crimp vs. Expansion Fittings

Every PEX system is only as good as its connections, so the fitting style matters as much as the pipe.

Expansion fittings (ASTM F1960) are made for PEX-A. The installer expands the pipe end with a tool, slides it over the fitting, and the pipe shrinks back down onto the barb. Because the pipe’s own elasticity does the clamping, the inside diameter at the joint stays close to full size, which helps flow. Expansion joints also don’t depend on a ring being squeezed to the right spec.

Crimp and clamp fittings (ASTM F1807 for metal insert fittings) are the usual choice for PEX-B. A copper crimp ring or stainless cinch clamp is compressed over the pipe and an insert fitting. The insert sits inside the pipe, so it narrows the waterway a bit at each joint. Crimp connections work well, but each one has to be made with a calibrated tool and checked with a go/no-go gauge.

Mixing systems is where trouble starts. Fittings are designed and listed for specific pipe types, so we stick with what the manufacturer lists for the tubing being used. When we quote a PEX repipe, we’ll tell you which pipe and which fitting system we plan to use and why.

Copper: Type L vs. Type M

Copper has been the benchmark for supply piping for a long time. It’s rigid, it doesn’t mind heat, and it can’t be damaged by sunlight. For residential water lines you’ll mostly run into two wall thicknesses.

• Type L has a medium wall. A 1/2-inch Type L tube has a wall of about 0.040 inch. It’s printed with blue markings and is the common choice for interior potable water lines.
• Type M has the thinnest wall of the common types, about 0.028 inch at 1/2-inch size. It’s printed in red. It’s legal for many residential water lines, and a lot of older Florida homes were built with it.

That extra wall thickness matters when corrosion is in the picture. Pitting has less metal to chew through on Type M, so if copper is the choice for a repipe, we generally recommend Type L. Copper takes more labor to install than PEX because every joint is sweated or pressed, and the material itself has historically cost more. As a general rule, a copper repipe runs noticeably higher than a comparable PEX job.

Pinhole Leaks and Aggressive Water

The most common reason we hear for leaving copper behind is pinhole leaks. A tiny hole opens in the pipe wall, usually from pitting corrosion on the inside, and it drips or sprays inside a wall or ceiling. Where there’s one, more tend to follow.

There’s no single cause. Water chemistry is a big one. Water with low pH, low hardness and low alkalinity is often described as soft and aggressive, and it’s harder on copper. Water quality references commonly flag pH below 6.5 as corrosive. High velocity, high pressure, chlorine levels and debris from a failing water heater have all been tied to pitting too, and most cases probably involve a combination.

What RO water has to do with it

Cape Coral treats brackish groundwater from the Lower Hawthorn aquifer with reverse osmosis, and it was one of the first large U.S. cities to rely on RO for its drinking water. RO strips out minerals very effectively. Raw RO permeate tends to have a low pH and almost no alkalinity or hardness, which is why utilities stabilize it before it goes out to customers.

Inside the house, the bigger concern is often a point-of-use RO unit or heavy softening. An under-sink RO system delivers very low-mineral water to the faucet, the fridge and the ice maker, and any copper downstream of it sees that water every day. If you run RO or a softener, tell us before we pick materials. It’s one of the reasons PEX gets chosen in homes that have had repeat pinhole leaks. If you’re also rethinking your treatment setup, our water softener and filtration page covers the equipment side.

If you’re not sure whether a wet spot is a pinhole or something else, leak detection is the place to start before anyone opens walls.

PEX in Florida Attics: UV and Heat

PEX has two weak spots, and Florida tests both of them.

Sunlight

PEX isn’t made for direct sunlight. The ASTM standard for PEX tubing includes UV resistance ratings, and many products are only rated for about 30 days of exposure total, counting time in storage and during construction. Industry guidance says PEX should be stored indoors in its packaging and kept shielded from sunlight. That rules out runs along an exterior wall or across a lanai without proper protection. Where pipe has to come outside, such as a hose bib or an outdoor shower, we transition to a material suited for it or sleeve and cover it.

Attic heat

A closed Florida attic on a summer afternoon gets hot. PEX handles hot water, but its pressure rating drops as temperature climbs. A common rating printed on PEX tubing is 160 psi at 73 degrees F and 100 psi at 180 degrees F. Normal house pressure sits well below those numbers, so a properly installed attic run is not near its limit. Still, good practice in an attic means a few things:

• Keep runs low, close to or under the insulation, and away from the hot roof deck.
• Stay clear of recessed light housings, flues and the air handler’s heat sources.
• Support the pipe on the spacing the manufacturer calls for, since PEX expands and sags more than copper.
• Leave room for thermal expansion so long runs don’t pull on fittings.

Done that way, attic PEX is a standard installation across Southwest Florida.

CPVC: The Third Option

CPVC is chlorinated PVC. It’s the cream or tan rigid plastic pipe you’ll see in a lot of Florida homes built from the 1980s on. It’s glued with solvent cement, it handles hot water, and it’s inexpensive. For a repipe, it usually lands between PEX and copper on overall cost.

The tradeoffs show up with age. Older CPVC can turn brittle, especially in hot attics where it heats and cools every day. Brittle CPVC cracks when someone bumps it, steps near it, or tries to cut into it for a repair. It also reacts badly to some fire-stop caulks, petroleum-based sealants and other building products that aren’t listed as compatible. And because it’s rigid, it takes more fittings and more joints, which means more glue points that each have to be made right.

We don’t rule CPVC out. It can make sense for a small section or to match an existing system. For a full repipe in an attic-routed home, though, most homeowners end up comparing PEX and copper, and CPVC is the choice we see least often for new work.

Side-by-Side Comparison

Here’s how the three materials stack up for a typical Southwest Florida repipe. Cost notes are relative, not quotes.

• PEX-A with expansion fittings: flexible, fewer joints, full-bore fittings, kinks can be fixed with heat. Must be kept out of sunlight. Usually the lowest total cost for a full repipe, along with PEX-B.
• PEX-B with crimp fittings: stiffer, lower material cost, fittings slightly restrict flow at each joint. Same UV rules as PEX-A.
• Copper Type L: rigid, heat and UV tolerant, long track record. Vulnerable to pinhole leaks in aggressive water. Highest labor and material cost of the three.
• CPVC: rigid plastic, moderate cost, solvent-welded joints. Can get brittle with age and heat, and sensitive to incompatible chemicals.

No material wins every category. In most homes we look at, PEX checks the most boxes, but we’ll recommend copper when it suits the house and the owner’s priorities.

Repiping for Insurance and 4-Point Inspections

A 4-point inspection looks at four systems: roof, electrical, HVAC and plumbing. Florida carriers typically ask for one on older homes, often starting somewhere around 25 to 30 years of age, though some ask for it on any purchase. On the plumbing side, the inspector notes pipe material, age, visible leaks and the water heater.

In general terms, here’s how insurers tend to view supply piping:

• Polybutylene is the big red flag. Many carriers won’t write a policy with it in the house.
• Galvanized steel in poor or aging condition is often flagged as well.
• PEX, copper and CPVC in good condition are generally accepted.

Every carrier sets its own rules, and they change, so check with your agent before you commit. What we can do is give you a material choice and documentation that lines up with what the inspector will look for. Our polybutylene and 4-point inspection guide goes deeper on identifying PB and what the plumbing section of the report covers.

Slab Homes: Rerouting Through the Attic

Most homes in our area sit on a concrete slab. In many of them, the original supply lines run under or through that slab. When those lines start leaking, you can chase each leak by opening the floor, or you can abandon the under-slab lines and run new pipe overhead.

A repipe usually takes the second route. We cap the old lines, run new supply lines through the attic, and drop down inside walls to each fixture. That avoids breaking the floor, and future leaks will be in places you can reach without a jackhammer. This is also why material choice and the attic rules above matter so much here: in a reroute, most of the new pipe lives in the attic.

If you’re dealing with one leak under the slab and the rest of the system is in good shape, a targeted fix may be the better call. Our slab leak repair page explains those options, and the slab leak warning signs guide covers what to watch for.

Manufactured Homes

Manufactured and mobile homes come with their own repipe considerations. Many were built during the years polybutylene was in wide use, and gray PB lines are something we expect to check for in older units.

The layout is different, too. Supply lines in many manufactured homes run under the floor, inside the belly wrap or in the crawl space, rather than overhead. That changes access. Rather than an attic reroute, we usually work from underneath, which means opening and resealing the underbelly material and supporting the new pipe properly off the frame.

Flexibility helps in tight spaces, so PEX is a common pick for these homes. Lines that run outside the skirting or near vents need protection from sunlight and from freezing on the rare cold night, and any exterior connections need to be sleeved or transitioned to a suitable material.

Drywall, Disruption and How Long It Takes

A repipe means opening walls and ceilings, but not as many as people expect. We cut small, planned access holes at fixtures and along routes where pipe has to drop down. Flexible PEX can often be fished through walls with fewer openings than rigid copper or CPVC would need.

After the new system is tested, those openings get patched. Ask any contractor you talk to whether patching is included, whether it’s taped and finished smooth, and whether texture matching and paint are part of it or left to you. Those details vary a lot from one quote to the next.

On timing, a typical single-family repipe takes a few days of work in the house, not weeks. Size, number of bathrooms, attic access and the material all affect that, and copper takes longer than PEX. Permits and inspections add their own steps. In most cases water is only shut off during working hours, and you have running water at night.

How We Help You Choose

When we look at a repipe, we start with the house: what’s in the walls now, how the water is treated, where the pipe can run, and what your insurer is asking for. From there we’ll recommend a material and explain why. If you have RO, a softener, a history of pinhole leaks or an insurance deadline, mention it up front.

HomeFlow Plumbing serves Lee, Charlotte and Collier Counties from our office in Fort Myers. If you’re in Cape Coral and dealing with RO-related questions, our Cape Coral plumbing page has more on that area. To set up a visit, call (239) 518-4198, email help@homeflowfl.com, or use our request form.