Mesastone® ASTM Reports

Trenwyth / Mesastone

Mesastone® Cleaning

Walls must be cleaned on a daily basis as block laying proceeds:

Masonry surfaces clean most effectively if the cleaning is done within 14-28 days after masonry installation. Mortar and grout smears that remain on the surface for a longer time result in a more difficult cleandown and may cause undesirable results.

Final cleandown of masonry surfaces should be completed before installation of windows, doors, hardware, light fixtures, roofing materials and any other non-masonry item that may be damaged by the cleaning product. If such fixtures have been installed, they must be protected before the cleaner is applied. All caulking and sealant materials should be in place and thoroughly cured
before cleaning begins.

Protect all surrounding metal and non-masonry materials, painted surfaces and plant life from contact with the cleaner, residue or fumes.

Masonry Cleaners:

Use Burnished Custom Masonry Cleaner by PROSOCO (dilute one part to 3 parts clean water), carefully following manufacturer’s instructions. Do not powerwash.

CAUTION! Never use muriatic acid on units.

Prior to overall application, always test the cleaner (minimum 4′ x 4′ area) to ensure suitability and desired results. Test each type of masonry and each type of stain. Allow test area to dry for 3 - 7 days before inspection and approval by the project architect or building owner. Clean test areas according to the application below and always make the test panel available throughout the cleaning project.

  • Always pour cold water into an empty bucket first before carefully adding detergent.
  • Never use hot water.
  • Handle in polyethylene or rubber buckets only.
  • Acidic materials and fumes will attack metal.

Exterior Test Application

The following cleaning procedure is recommended unless otherwise indicated during testing:

  1. Thoroughly saturate a large portion of the masonry surface with clean water.
  2. Using a densely-packed, soft-fibered masonry washing brush or low-pressure spray (50 psi maximum), apply diluted solution freely. Do not apply Burnished Custom Masonry Cleaner with pressure spray above 50 psi. Such an application will drive the chemicals deep into the surfaces making it more difficult to rinse completely and may cause efflorescence.
  3. Depending on the absorption rate of masonry and drying conditions, allow cleaning solution to remain on the wall for approximately five (5) minutes. Do not allow cleaner to dry into the masonry because it may leave a residue and cause staining.
  4. Reapply cleaning solution and scrape off heavy buildup of excess mortar using a wooden scraper. Take care to avoid damaging the masonry surface. Do not use metal scrapers, which may contribute to metallic staining.
    Note: Avoid more than one reapplication over the same area. Repeated applications may cause a white detergent film to be deposited on the masonry surface. If mortar deposits are not softened after initial application, allow the solution to remain on the wall for a longer period of time making sure that the cleaner does not dry into the masonry.
  5. Rinse thoroughly with fresh water, removing all cleaning compound, free sand, loose materials and debris. Thorough rinsing is extremely important to ensure that all residues are removed from the porous masonry.

Note: To avoid streaking, keep adjacent and lower wall surfaces wet and rinsed free of
cleaning residues.

Interior Application:

Follow the cleaning procedure outlined for exterior surfaces. Rinse thoroughly with fresh water using a sponge or soft-fiber brush. If conditions do not allow sufficient water for complete rinsing, use a neutralizing rinse and the following procedure:

  1. Rinse first with fresh, clean water.
  2. Apply neutralizing rinse of two ounces household ammonia to one gallon of clean water.
  3. Saturate thoroughly and allow neutralizing solution to dwell on the surface 3 to 5 minutes.
  4. Apply a final rinse of fresh, clean water.


  • Keep walls clean by using brushes or rags and the burlap squares supplied on the Mesastone pallets.
  • Do not allow excess mortar lumps or smears to harden on the finished surfaces.
  • Remove green mortar with burlap or a dry cloth.
  • Wipe masonry blocks clean with burlap (provided with each cube) as the blocks are laid each day.
  • Protect stored materials and the wall prior to completion to prevent excessive water entry and external soiling.
  • Test an unexposed portion of adjacent metal fixtures with the cleaning solution. If corrosion or staining occurs, protect the exposed portions. (Harsh cleaning methods after walls have been erected may mar the surface of the blocks.)
  • Protect adjacent masonry and floor area by saturating with water and flushing away any cleaning solution before it dries.


  • Two plastic or hard rubber buckets
  • Rubber gloves
  • Soft fiber masonry brushes (or whitewash brushes)
  • Wooden, plastic or other soft, non-staining scraping device
  • Supply of “clean” wipers, such as lint-free cloths or paper towels
  • Clean water
  • Burnished Custom Masonry Cleaner (dilute one part to 15 parts of clean water). Do not apply
    with pressure spray above 50 psi. It will cause efflorescence.

Cleaning Procedure 1

  1. Brush clean water liberally on the surface area to be cleaned. Brush approximately one square yard at a time.
  2. It is important that the masonry wall be kept wet at all times. Do not use dirty water.
  3. Apply cleaning solution brushing in a circular motion to remove any unwanted mortar smears.
  4. Remove excess lumps of mortar with the soft (wood or plastic) scraping device and re-apply cleaning solution.
  5. Allow cleaning solution to remain on the surface for two or three minutes then wash off with liberal amounts of fresh, clean water.
  6. Wipe the walls down completely dry with clean, dry wipers.

Cleaning Procedure 2
If liberal amounts of water cannot be used, an alternative procedure may be employed.

  1. Soak a clean wiper in the cleaning solution. Wring it out so it is wet enough to dampen the surface, but dry enough so that the solution will not run down the wall.
  2. Allow the solution to remain on the surface for two or three minutes. Remove excess lumps of mortar with the soft scraping device and repeat Step #1.
  3. Wipe the wall completely dry with clean, dry wipers.

Note: To remove mortar smears that have been allowed to harden on the wall and cannot be removed by following the procedures listed above, a solution of Burnished Custom Masonry Cleaner by PROSOCO may be used with a dilution ratio of 1 part cleaner to 3 parts clean water, strictly following manufacturer’s instructions.

WARNING! Never use muriatic acid solutions on Mesastone.

Final Cleandown:

Clean the completed walls with a detergent masonry cleaner strictly following the manufacturer’s instructions including thorough rinsing. Do not use acid or abrasives on the block surfaces. For stubborn mortar stains or smears, a 3:1 solution of Burnished Custom Masonry Cleaner by PROSOCO may be used as long as the walls are thoroughly wetted with clean water before applying the cleaning solution and thoroughly rinsed with clean water immediately after washing. Failure to strictly follow manufacturer’s instructions can result in permanent damage to the finished faces. DO NOT POWERWASH.


Mesastone units, properly installed and cleaned, need virtually no maintenance other than routine cleaning with standard commercial grade cleaning agents such as PINESOL® or FANTASTIK®. For tough stains, contact manufacturer for specific cleaning recommendations. DO NOT POWER WASH.