Is pressure washing a tile roof a bad idea?

Put the roofing documents side by side and tile reads differently from the rest. The Asphalt Roofing Manufacturers Association (ARMA) writes “Never use a pressure washer to clean an asphalt shingle roof,” and the Metal Roofing Alliance tells metal roof owners “NEVER use a power washer” in the capitals of its own guide. Those are bans.

Eagle Roofing Products, a concrete tile maker, writes something else. It does not forbid pressurized water on its tile. It recommends water alone and puts a number above it: the pressure should never exceed 1200 pounds per square inch. That difference is real.

A ceiling is not a permission, though. A ceiling marks the most the maker will accept, and it sits on top of a default the maker states first, which is water with no chemistry. Eagle's figure also belongs to concrete tile and to no other roof, which is why a published pressure number does not travel from one material to the next. What the method itself is, as a term, is set out under pressure washing, defined.

Eagle's 2019 cleaning article puts the default and the cap in one sentence: when a tile roof is cleaned, “it is recommended that you use only water with the water pressure never exceeding 1200 pounds per square inch (psi).” Its 2020 article repeats both halves: “It is recommended to only use water when cleansing the crown of the home and pressure should not exceed 1200 psi.”

The 2020 article also says that specialists “may use a high-pressure power washer sprayer” on concrete tile, and names a lift as another piece of equipment they may bring. Read in place, that sentence sits beside the cap and the water-only recommendation, not in place of them. It describes equipment a specialist may carry; it does not raise the ceiling or drop the default.

How to read 1200 psi as a figure, and why it is not a figure to dial in, belongs to a safe pressure for a concrete tile roof. For this question the point is narrower: Eagle's own tile guidance keeps a pressure washer on a short leash, and the leash is written for concrete tile only.

Water alone does not always shift what is on a roof, and Eagle's 2019 article allows for that: “Depending upon how dirty a roof appears and what pollutant is on the roof, it may be necessary to use a cleaner in conjunction with the pressurized water, but only in the most diluted solution possible.”

The same article gives the reason for the caution. The cleaner should be compatible with concrete, Eagle writes, because some products “can affect the PH of the tile or even etch the surface.” Its 2020 article adds that chemicals should be used sparingly, and urges “the most diluted solution possible that will be compatible with concrete.”

The pressure is only half of what a tile maker worries about. The other half is the person holding the wand. Eagle's owner information is blunt: “Walking on or putting pressure on tiles can potentially cause damage. Our recommendation is to stay off your roof.”

Water makes that harder. Eagle writes that “Walking on a roof can be difficult and dangerous and introducing water only heightens these concerns,” and its owner information warns, “Be careful, tiles can be slippery.” Eagle also writes that roof tile “must not be used as a staging area or work platform.”

Eagle's 2020 article adds that a contractor walking a steep-sloped pitch while cleaning should use a fall restraint apparatus. The full set of conditions the trade publishes for anyone who steps onto a tile roof is laid out in whether anyone walks on the roof during cleaning.

A tile that breaks underfoot is not cosmetic. The Tile Roofing Industry Alliance (TRI Alliance) writes that “Broken tiles may cause problems by allowing water and UV rays to penetrate through to the underlayment and damage it,” and Eagle's owner information says tiles broken by foot traffic should be replaced as soon as possible.

Neither document hands that job to a cleaner. TRI Alliance writes that it “strongly recommends that you contact a professional roofing contractor to repair or replace broken tiles.”

The warranty side points the same way. Eagle's Florida limited warranty text, as archived, lists “damage to the tile caused by roof traffic or other trades” among its exclusions, and Eagle's 2025 article says, “Often, roof tile manufacturers specifically do not warrant breakage due to foot traffic.” Whether a particular roof's warranty is affected is a question for the tile maker and the installer.

Put together, the case against pressure washing a concrete tile roof is not that the maker forbids it. It is that everything the maker attaches to it points the other way:

• The default is water. Eagle's recommendation is water alone, and 1200 psi is the most it accepts, not a starting point.
• Chemistry stays weak. A cleaner comes in only when needed, in the most diluted solution possible, and it should suit concrete.
• Feet stay off. Eagle recommends staying off the roof, and water makes tile slippery.
• Breakage is routed. TRI Alliance routes a broken tile to a roofing contractor, and foot traffic damage is excluded from Eagle's Florida warranty text.

Roof cleaning in general leans the other way, toward a soft wash, a cleaning solution followed by a low-pressure rinse; the reasons are traced in why roof cleaners use low pressure. Eagle's 2025 article gives owners one practical step either way: ask the roofing contractor what their method is for walking on a tile roof before they start. What happens around the house on the day, including whether you can stay home during roof cleaning, is its own answer.