Introduction
- Exposure to weather, including UV and rain UV weathered deck Weathering is the biggest single, and most important cause of discolouration. ...
- Staining due to natural or introduced causes Biological staining Sapstain or Bluestain moulds are usually an issue when the timber is freshly cut. ...
- Chemical changes within the wood resins, or “extractives”
What does it mean when wood burns blue?
Wood that burns blue usually means it has a hear of about 2300 degrees or hotter while a green flame may indicate that their is something extra burning with your firewood such as chemicals or pesticides. What Does a Blue Flame Mean When Burning Wood? Perhaps the easiest color change to notice in a flame is the color blue.
What does blue stain look like on wood?
The affected wood is then said to be “sap-stained.” The discoloration varies depending on the infecting organism, wood species and moisture situation, but a blue stain is the most common type. Blue stain shows as bluish to bluish-black, or gray to brown. The affected areas can be spotty or streaky.
What are the blue-black zone lines on wood?
The blue-black zone lines are boundary markers of fungi colonies coming into contact with each other. Unlike wood with other fungal stains, spalted wood is rare, high-priced and in high demand. The reason is that the timing has to be just right to harvest spalted wood.
Can you be allergic to blue stained wood?
So if you made paneling or flooring form blue stained wood there would be no more spores on the wood then in the air. There are more spores in carpet then anywhere else not counting all the bad chemicals to make it. Some folks are allergic to pine wood, eastern red cedar wood and some other types.
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What does Blue on lumber mean?
What makes the lumber blue? Blue stain is a common cause for the discoloration of lumber. Certain dark-colored microscopic fungi cause a bluish or grayish discoloration in the sapwood of the tree.
Why is some construction wood blue?
0:033:04Information on BluWood Treated Wood - YouTubeYouTubeStart of suggested clipEnd of suggested clipGoes basically by the name of blue wood is how you'll commonly find it at retail stores andMoreGoes basically by the name of blue wood is how you'll commonly find it at retail stores and basically what it is is it's a treatment. That's added to lumber. To make it more moisture.
What is blue colored wood used for?
BluWood is a treated wood used in the framing of residential or commercial buildings. According to the BluWood website, they “provide the building industry with a new level of defense.
Is Blue wood safe?
You can distinguish borate-treated wood by its blue color. Builders often use this type of lumber in homes, to defend against termites. While it is considered low-toxicity lumber and safe for humans, it is not intended for exposed use in outdoor areas. Not only can it rot, but its chemicals may leach into the soil.
Is there any natural blue wood?
OK, so it's not like smurf-blue, but still: Blue hardwood! It comes from Talipariti elatum, the so-called “Blue Mahoe” tree, which is native to the Caribbean and is, apparently, the national tree of Jamaica. Turns out it also grows very quickly and shows some promise for sustainable forestry.
Why are some 2x4 green?
Green does not refer to any hue or coloring. In fact, lumber at its basic form is considered green lumber. It's milled to a certain dimension, finished to an extent (e.g. eased edges, rough face, smooth on all sides) and then shipped out for consumers to purchase. Moisture content is usually pretty high.
Why are 2x4 studs pink?
A: They are colored because they are "pre-cut" studs and are easily seen on jobsites so they aren't mistaken for unmitered standard length lumber. These are measured and mitered (squared) at the sawmill and sold for various height interior walls. Makes building walls much quicker during framing.
Why are some studs purple?
During the post-World War II housing boom, a company called Temple-Inland introduced the now infamous purple 2×4 studs as a marketing tactic to compete against Douglas fir studs from the Pacific Northwest.
What is blue plywood used for?
Blue Ribbon® Sturd-I-Floor Ideal for use in residential and light commercial construction, with the span and sealing to keep moisture at bay, Blue Ribbon® OSB Sturd-I-Floor panels are also recognized for their ease of installation.
Does treated lumber have arsenic in it?
Arsenic in Old Pressure-Treated Wood Most pressure-treated lumber sold before January 2004 was treated with chromated copper arsenate (CCA for short), which contains arsenic. Swallowing arsenic is known to cause cancer in humans.
Is treated lumber toxic?
According to the National Academy of Sciences, long-term exposure to the arsenic that is found in some types of CCA-pressure-treated lumber can increase the risk of lung, bladder, and skin cancer over a person's lifetime.
Can you put treated lumber in your house?
Yes, you can use pressure treated lumber indoors for any interior application except for surfaces that directly contact food, such as cutting boards and kitchen countertops, and where pets can chew it. Chemicals in the treated wood won't leach on the surface; thus, it's safe indoors.
What is blue stain?
Sapstain or Bluestain moulds are usually an issue when the timber is freshly cut. They thrive on the extractives and high moisture content of green timber. They tend to be a dark blue-grey or black in appearance, hence the term “Bluestain”. The damage that they do over time is superficial as it usually effects the outer layer only.
Why is my timber turning silver grey?
2. Staining due to natural or introduced causes. Biological staining. Sapstain or Bluestain moulds are usually an issue when the timber is freshly cut.
What causes wood to change color?
The colour of timber is caused by natural pigments . This is defined by a group of chemicals known as quinones and polyphenolic compounds. Quinones are the true pigments, as the polyphenolic compounds are clear.
Why is weathering important?
It is the most important structural component of timber. 1. Exposure to weather, including UV and rain. Weathering is the biggest single, and most important cause of discolouration. There are two main mechanisms behind this: Exposure to rain bleeds out the extractives, including the natural pigments (quinones).
What is the best way to clean UV weathering?
For UV weathering, use an oxalic acid timber cleaner like Grey Deck Cleaner. A pressure washer is also a useful tool. But if the weathering is quite heavy, a light sand prior to the application of Grey Deck Cleaner is recommended. For iron staining, you must.
What are extractives in timber?
Extractives have been discussed earlier in a few previous articles, but are the pigments, tannins, and other resins.
What is the glue that holds timber together?
Another key component of timber that can effect it’s change of colour over time is lignin. Lignin is the glue that holds the timber fibre together. It is the most important structural component of timber. 1.
What Does a Blue Flame Mean When Burning Wood?
Perhaps the easiest color change to notice in a flame is the color blue. This is because it is markedly different from the traditional and perhaps expected orange flame. As you may remember from science class a blue flame can simply indicate the intensity of the heat of the flame.
Is Blue Fire Dangerous?
If you are simply burning firewood that is producing a blue flame then the good news is that no, it is not dangerous. It simply means that no fuel is going to waste as the carbon is being used in its entirety.
Why Is My Firewood Burning Green?
Another color that may come as a surprise if you were expecting the traditional orange-colored flame is green.
Final Thoughts
Generally, blue or green flames are not something to worry about, especially if you know the reason behind the color.
What causes blue stain?
People (some and not all) are indeed allergic to fungi spores and not just mold or mildew spores. From the original questioner: Actually it does matter. Blue stain is caused by a fungus (mold).
Why is my pine stain blue?
Blue stain is caused by a fungus (m old). It doesn't matter if the stain is caused by a beetle, stacking green boards together to encourage the fungus, pine logs cut in the summer and staining in the yard or in stacks of stickered pine. Once you kiln dry it there probably will be no problem as long as the wood stays dry.
Is blue stain moldy?
Blue stain is a sap stain and is not mold. The SPIB does not count it as a defect and no strength loss. Mold grows on wood above 20% MC and thus the SPIB has set the standard for Kiln dried wood below 19%. Spalted wood is moldy and where the color comes from and it does weaken the wood.
Is spalted wood moldy?
Spalted wood is moldy and where the color comes from and it does weaken the wood. Blue stain pine is rare and hard to produce at a greater cost (this keeps the price up so do not let the cat out of the bag). Handle the market with care. Mold is a problem and a health risk.
Do blue stained wood spores exist?
Spores are present in the air. Spores are not present inside the blue stained wood. So if you made paneling or flooring form blue stained wood there would be no more spores on the wood then in the air. There are more spores in carpet then anywhere else not counting all the bad chemicals to make it.
Does drying out a school kill mold?
If it were simply necessary to dry out a school or home with mold, life would be easy. People are allergic to the spores of the fungi (simple explanation: the seeds) and these float around, etc. Drying does kill the fungi, but the spores are still there. On the other hand, spores are in the air around us.
Is blue stained wood a defect?
It's a defect because you can't sell a lot of it, not because you can't sell any of it. From contributor L: There is a small mill near where I live (12 employees) that specializes in wood siding and molding. The blue stained wood has been a big seller with them for years. From the original questioner:
How deep does chemical stain penetrate?
Chemical stain develops just below the surface and can penetrate deep into the wood if conditions are favorable. Requirements for the development of chemical staining are similar to that of fungal staining – temperatures above 50 degrees and a moisture content above 20 percent.
Why is spalted wood harvested?
The reason is that the timing has to be just right to harvest spalted wood. If a spalting log is cut into lumber too soon , the color characteristics are less pronounced. When the log is cut too late, the wood is too decayed and the lumber is useless.
What is the difference between sap stain and mold stain?
Basically, the difference between mold and sap stain is the penetration into the wood. Mold is usually a surface growth, but it can stain the wood deep below the surface. Areas affected by mold show stain even if planed to nominal thickness – especially hardwoods such as oak.
What are the three groups of stains in wood?
These stains in wood can be classified into three groups: fungal, mineral and chemical. Fungal Stain. This group of stains is caused by minute parasitic organisms that need water, warm temperatures and oxygen to grow.
What woods have discoloration?
These are unsightly blue-black or dark-gray discolorations mostly in oak, redwood, cedar and cypress. The heartwood of these species has a high content of tannin and tannin-like extractives. When iron or steel comes into contact with the wood, a chemical reaction takes place, resulting in discoloration.
What color does sapwood fade to?
However, one should keep in mind that the brilliant colors will fade to a light-brown or medium-brown over time. Chemical Stain. Chemical stains result from the oxidation of naturally occurring chemicals in the wood cells of the hardwood. This is especially true with species with the highest proportion of sapwood.
What color is heartwood?
We all associate certain colors with various wood species: light brown with oak, burgundy red with aged cherry and mahogany, or tan with maple. After several years of growth, the wood cells become inactive and increase extractive content like resin, gum and tannin to become heartwood.
