This week a professional pressure-washing contractor cleaned small areas of the east Phase II entrance wall and median curb to allow us to evaluate the effectiveness of the chemicals and techniques they use. Four areas of the east entrance wall were tested; Areas #1 & #2 were treated for both rust & efflorescence , area #3 was treated for efflorescence only and area 4 was treated only for hard water stains. Areas 3 & 4 had no visible rust deposits before cleaning. A section of the entrance median curb was treated for rust stains.
The board will discuss cleaning rust and calcium stains from both Phase I and Phase II entrance wall, as well as removing rust stains from the median curbs at both entrances at the April 8, 2025 board meeting.
Above – Curb – treated for rust stains
Above – Test area 1 before cleaningAbove – Test area 1 – treated for rust & efflorescence stains
Above – Test area 2 before cleaningAbove – Test area 2 – treated for rust & efflorescence stains
Above – Test area 3 before cleaningAbove – Test area 3 – treated for efflorescence stains only
Above – Test area 4 before cleaningAbove – Test area 4 – treated for hard water stains only
3 thoughts on “Entrance Rust & Calcium Deposit Cleaning Test”
I think it looks good. You and Jeff insisted on “White ox” for rust and white vinegar for the bricks according to you Ron and the brick layer. He maybe using Oxalic acid or F9 Barc, you didnt want to damage the plants or bricks.
How long it will stay clean depends on a couple of factors. Iron and hard water stains from sprinkler water will stay clean as long as we keep the sprinklers from spraying the walls (and we’re working with the irrigation people to arrange that).
But some of the calcium stains are “efflorescence”, which occurs when sunlight heats moisture that’s inside the brick and causes it and the calcium it carries with it to be deposited on the outside where it becomes visible. How long efflorescence stains will stay clean is harder to predict since bricks can absorb water from dew and rain, and bricks are manufactured using a small amount of lime (calcium oxide). Since the walls are over 30 years old we expect much of the original lime has already leached out and the walls it should be many years before we need to do this again. If we follow up by applying a sealant to the walls, they will remain clean longer.
I think it looks good. You and Jeff insisted on “White ox” for rust and white vinegar for the bricks according to you Ron and the brick layer. He maybe using Oxalic acid or F9 Barc, you didnt want to damage the plants or bricks.
It seems that the hard water stains cleaner performed best. Did you ask , how long will it stay clean?
How long it will stay clean depends on a couple of factors. Iron and hard water stains from sprinkler water will stay clean as long as we keep the sprinklers from spraying the walls (and we’re working with the irrigation people to arrange that).
But some of the calcium stains are “efflorescence”, which occurs when sunlight heats moisture that’s inside the brick and causes it and the calcium it carries with it to be deposited on the outside where it becomes visible. How long efflorescence stains will stay clean is harder to predict since bricks can absorb water from dew and rain, and bricks are manufactured using a small amount of lime (calcium oxide). Since the walls are over 30 years old we expect much of the original lime has already leached out and the walls it should be many years before we need to do this again. If we follow up by applying a sealant to the walls, they will remain clean longer.