Hardwood Floors August/September 2018

AT THE SITE Common Stains and Discolorations (Continued)

Mineral streaks are from natural interactions between the living tree and its environment. ese are allowed in many ooring grades and will not sand out. No two trees from the same species are identical, no two boards from the same tree are identical, and color, grain pa erns, and unique characteristics can drastically vary even within one individual plank of wood. Sap Stains

(drying wood and stickers) that occurs during the drying process. ese stains cannot be sanded out and are permissible in many ooring grades. Moisture Stains Wood or nish can change color

with exposure to moisture. ese are the stains we have all seen anytime we deal with moisture-related issues. ey may include moisture-induced rust stains; stains from plant pots; pet feces and urine;

(Blue-Stain or Brown-Stain)

Sap stains are a discoloration in the sapwood. ese stains normally are caused by the growth of certain fungi on the surface and in the interior of the

mildew-related, decay-related, fungus/mold-related stains; and many more. If moisture caused the stain, it would be considered a moisture stain. Iron Stains

wood when the moisture content and surrounding conditions are prime for this fungal growth. e wood may become prone to this fungi in standing or fallen timber, or during seasoning before the kiln-drying processes. is discoloration is o en known as blue-stain or brown- stain due to the color of the fungi. In kiln-dried lumber, this fungus is not living, does not cause decay, is not a mold, will not spread, is not a health concern, and will not a ect the structural integrity or the strength of the wood. Note that sapwood is the active wood near the outside of the living tree. It is o en lighter in color than the heartwood of the tree. is color variation is normal and acceptable in all grades, and must not be confused with sap stain. Sticker Stains (Shadow) Sticker stain can sometimes

Iron stains can occur as a result of a chemical reaction between wood tannins, water, and iron. These stains are most common when filings from scrapers or some types of abrasive minerals have not adequately been removed from the floor

before application of water or water-based finish. They can also become apparent from flooring fasteners, metal buckets, or objects that have been placed on the floor with exposure to moisture. Tannic Acid

Discoloration (Tannin-Pull)

Tannic acid includes various naturally occurring, soluble, astringent, complex phenolic substances found in trees (and plants) as a way of protecting the

appear as a discoloration on the face of a board associated with the location of the stacker sticker. Stickers are thin strips or boards used to separate the layers of

tree from insects, re, and bacteria. High levels of tannic acid present in woods like oak, walnut, and mahogany can produce a dark discoloration when coming in contact with some products used in the nishing and maintenance of wood oors.

lumber stacked in a pile to permit air circulation during the seasoning of lumber. ese stickers can leave a brown or blue stain that develops in seasoning lumber where it has been in direct contact with the boards. Sticker stain discoloration is the result of naturally occurring chemicals within the wood

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