2024-25_NTCA_Reference_Manual_dig_dwnld

Stains on Natural Stone

Problem

Prevention

Cure

Absorption of materials such as paint, rust, food, tobacco, iodine, lead, ink, liquors, and oil-based products.

During construction, cover the installation with kraft paper, taping the joints and edges. For heavy traffic areas, apply a minimum of 1/4 in (6 mm) plywood over the kraft paper. It is not the responsibility of the tile contractor to place the plywood. Refer to TCNA Handbook Section “Notes/Defi nitions” titled “Protecting New Tile Work.” For ongoing protection, regularly apply a penetrating or impregnating sealer as necessary per manufacturer’s recom mendations.

See "Stain Removal," (page 160).

Do not allow contaminants to come into contact with stone.

Blot spills immediately with paper towels or rags for minimal damage.

Use of adhesives or other setting materi als that result in "bleeding" through the stone to the finished surface.

Wiping a spill may spread it over a large area, making a larger mess.

Remove and replace the stone. A color enhancing sealer may be used. Poultice materials may be needed for stain removal, grinding may be required for some mortar deposit damage.

Test questionable setting materials to determine whether they will penetrate the stone and stain the surface. Use only materials recommended for stone setting. The use of white dry set cement mortar or rapid cure setting materials might be necessary to avoid this issue.

TEST INCONSPICUOUS AREA FIRST to determine desired results.

Mortar deposits and stains.

Clean the area immediately, removing the mortar deposit and residue.

Floor should be refinished by qualified persons.

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NTCA Reference Manual | 2024 / 2025

Chapter 6 | Natural Stone Installations