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Now that I know how wood flooring can be toxic, I wanted to find out more about solid hardwood flooring. If you want to find out types of wood flooring, how each one can be toxic and how you can minimize hazardous volatile compounds (VOCs) from it, please read my previous post ‘Non Toxic Wood Flooring For Your Home – Which Wood Flooring Is Non Toxic?‘ I originally wanted to put solid hardwood flooring in my home. Unfortunately, I live in a condo so I wasn’t able to put solid hardwood flooring. My next option is to put engineered hardwood floor. However, I wanted to share with you what I have already researched about solid hardwood flooring. Engineered wood flooring has some similarities with solid hardwood flooring anyway since it has a solid hardwood layer on top. In this post, I share with you what non toxic solid hardwood flooring options you have when you put solid hardwood flooring in your home.
Non Toxic Solid Hardwood Flooring Options
When choosing a solid hardwood flooring, there are several things to consider. One flooring option doesn’t fit everyone’s needs. You will have to think about which choice is the most non toxic option but at the same time serves your need for installation, maintenance, repairing and look of your home. Let’s take a look what you will have to decide!
1. Find Out The Type Of Subfloor Of Your Home.
I feel that solid hardwood is the most non toxic material out of all hardwood materials since it doesn’t contain glue like engineered and bamboo wood. Also, solid hardwood is usually nailed down to the sub floor and it can also be stapled down for installation. These methods do not require glue. Since glue can be toxic and can contain a lot of volatile organic compounds (VOCs), I really liked solid hardwood materials and installation methods. However, I have found out I couldn’t install solid hardwood flooring in my home. I live in a condo and condos have concrete sub floors. Since solid hardwood is nailed or stapled down to the sub floor, it can’t be installed on concrete using these methods. The only way you could use the nailing method for solid hardwood flooring is to install an additional sub floor to accommodate nailing or stapling. However, many condos may not permit solid wood flooring in the first place. Then you would have to choose from other wood flooring options. Therefore, find out if your home can accommodate nailing or staple installation of a solid hard wood floor. If you have a concrete sub floor, you will have to install a plywood sub floor first which will result in more work and cost. If you live in a condo, you may not even be able to put a sub floor of plywood over concrete because of bylaws that regulate the installation of new flooring.
2. Decide If You Want Unfinished VS Pre-Finished Hardwood Planks.
Solid hardwood flooring is given a protective finish to protect wood from damages or wear and tear. You have to decide if you want unfinished solid hardwood or pre-finished hardwood flooring when you pick solid hardwood flooring. Unfinished solid hardwood planks are sanded and finished on-site after installation. Pre-finished solid hardwood planks, on the other hand are already sanded, stained and sealed at the factory. Therefore, you can just install them without having to finish them on-site. Which one is better depends on what you want. They both have advantages and disadvantages. Here are some of the differences between the two.
Pre-Finished Hardwood Flooring Advantages
One of the main differences between unfinished and pre-finished hardwood flooring is time. With unfinished flooring, sanding can take about 2 days. After staining and before using a finish, you may have to be off the floors about 12 -24 hrs. During finishing, if using a water-based finish, you will have to wait for about 2-4 hrs for finish to dry between coats. With oil-based finish, it is an even longer time to wait between the coats which is 8-10 hrs. Water-based finish requires less time to dry but it will require more coats than oil-based finish since it is less durable. With pre-finished hardwood flooring, you can start walking on the floor after the installation. You do not need any sanding, staining or coatings on-site. This makes pre-finished hardwood flooring very convenient.
Maintenance And Durability
Pre-finished hardwood boards are typically coated with multiple layers of polyurethane finish with aluminum oxide and cured under UV lights. This chemical process and coatings make the finish extremely durable and strong. When the finish is sealed at the factory, the factory can put more coats so much faster than it is done on-site. On-site finishing can’t copy that process since it will take a very long time. On-site finishes usually have 2-3 coats of finish whereas factory finish has 5-7 coats. Factory pre-finished solid hardwood flooring finish is more durable so it is less prone to get scratches and damaged. Therefore, it requires less maintenance than on-site finishes. It usually comes with 25 or more years of manufacture’s warranty whereas on-site finish usually has a warranty of 3-5 years.
No Dusts Or Odors
For pre-finished hardwood flooring, the sanding and applying a finish is done at the factory. Therefore, you don’t have to deal with dust from sanding and odors from harmful VOCs while a finish is being dried and cured. VOC off-gassing is most severe during application and the drying of hardwood floor finishes. Although VOCs may continue to off-gas a small amount after the hardwood is dried and cured, you can avoid large amounts of VOCs in this way since application is not done on-site.
Unfinished Hardwood Flooring Advantages
Check out unfinished solid hardwood flooring products.
With unfinished solid hardwood flooring, you can choose to have natural oil sealers or shellac as a finish if your installer have it available. (You can also do it yourself if you are into DIY remodeling of your home) Natural oil sealers or shellac is the most non toxic finish option out of all finish options. With pre-finished hardwood, they are already finished at the factory, therefore, you can not choose finish of your choice. Most pre-finished solid hardwood boards are finished with polyurethane. There are pre-finished solid hardwood planks with natural oils but it is very hard to find. Therefore, if you want to use natural oil sealers, unfinished solid hardwood flooring may be a better option for you.
Smooth Look & Sealed Lines
Pre-finished hardwood plank is chemically treated with polyurethane individually and it is already sealed at the factory. Therefore, it doesn’t get sealed on-site. That creates beveled edges. That means when pre-finished hardwood floor is installed, the floor will have a visible line between planks. Since the lines between the planks don’t get sealed when they are installed, dust or dirt can get caught between the lines in the planks. Water can also get in more easily and cause mold. Unfinished hardwood floors, on the other hand, don’t have any visible lines between the planks after installation. The lines between the planks get sealed when they are finished on-site. Therefore, it creates a smoother look. In addition, wood flooring that is finished on-site has more of a real wood feel compared to a pre-finished floor with factory sealed polyurethane and aluminum oxide. Some people think pre-finished hardwood flooring looks less real.
Repairs And Refinishes
It is easier to repair an on-site finished hardwood floor than a pre-finished hardwood floor. If one piece of on-site finished hardwood floor plank gets damaged, you can easily sand the surface of the piece and refinish it. Pre-finished hardwood floor, on the other hand, may require a whole section or entire floor to be sanded and finished. When hardwood floor is refinished, the surface is sanded first to have natural hardwood parts shown again so that a new finish can be applied. However, this is sometimes not easy to do with pre-finished floors since it has a thicker coat of finish applied by the factory. Although thick coats of a finished surface makes the surface a lot more durable than an on-site finished surface, it is harder to refinish once the damage happens. Pre-finished surface requires a lot of sanding due to the thick coats and it will reduce the thickness of the hardwood after sanding is done. This limits how many times the floor can be refinished and also how much of the floor needs to be sanded when there is damage. On-site finished hardwood floor can be refinished more than pre-finished hardwood floors and it is easier to repair damages.
3. Decide Species And Style Of Wood.
You also have to decide what type of solid wood species you want for your solid hardwood flooring. Each wood species come with a different hardness, texture and color. All hardwood can get damage such as dents or scratches. However, some woods are harder than others making them less vulnerable to damage. Wood species come with a Janka hardness rating which measures hardness and resistance of wood species to denting and wear. Although Janka rating is not the only thing that determines how durable a wood floor is, it can help you choose which species are strong to begin with. Softer wood will be more prone to damage from furniture and foot traffic. However, overall appearance and durability of the floor will also depend on other factors such as what type of finish the floor has, how much traffic there is, how well it is maintained or what type of core is used for engineered flooring, etc.
Wood species will have a Janka hardness rating of high range about 2000-3000, Mid range of 1300 or Low range of 1000. Some examples are as follows.
Hardest: Brazilian Cherry (2350), Brazilian Walnut (3684) or Santos Mahogany (2200)
Softer wood: Cherry (995) or Black or North American walnut (1010)
Wood species such as Red Oak, White Oak, Maple, Hickory, Birch, American Cherry or American Walnut are some of the most popular hardwood species for hardwood flooring. Although a wood species such Brazilian Walnut is much harder wood, it can be very hard to cut, nail, stain, sand or refinish due to the hardness. Therefore, it has higher wood, installation, refinishing costs. Oak is the most popular choice for hardwood floors. It is widely available and also affordable. It has obvious grain patterns which helps to hide dents and scratches. Therefore, it is often used in high traffic areas. However, since oak is not one of the harder woods, it is recommended to use furniture pads to avoid scratches. Maple has a higher hardness rating than Oak and it is more resistant to dents & scratches. However, some maple species have very mild or no grain pattern and make the scratches on the wood floor very visible. When you decide which species to go with, you will have to look at color, texture, grain pattern, color variation, plank size and overall look and feel of the wood that suits your style. In addition, if sustainability matters to you, you can choose solid hardwood that is FSC certified. Forest Stewardship (FSC) certifies a forest that is managed in an environmentally appropriate, socially beneficial and economically viable manner. FSC prohibits deforestation, illegal logging, restricts the use of pesticides, limits clearcut sizes, and protects the rights of indigenous people, endangered species and ecosystem. FSC certification label means the wood is harvested sustainably.
Check out Red Oak hardwood flooring products.
Check out White Oak hardwood flooring products.
Check out Maple hardwood flooring products.
Check out Hickory hardwood flooring products.
Check out Birch hardwood flooring products.
4. Decide The Type of Hardwood Finishes.
Solid wood itself is a natural material and non toxic. However, a protective finish we give to the wood floor after installation can have toxic chemicals and emit volatile compounds (VOCs) into the air. Finish is applied to the hardwood floor after the installation to give wood protection from damages, wear and tear. Depending on which finish you choose, it will have and emit different amount of VOCs. Some common VOCs from hardwood finish includes toluene, benzene, formaldehyde, xylene and arsenic. These chemicals off-gas at normal room temperature and they can cause headache, irritation of eyes, nose & throat, birth defects, chronic lung conditions and cancer. Chemicals such as benzene or formaldehyde are known human carcinogens.
VOCs are off-gassed from a finish the most while the finish is being applied, dried and cured. This means we are exposed to VOCs the most during application, drying and curing of hardwood finish. However, this doesn’t mean hardwood finish won’t off-gas VOC’s after curing is finished. It will continue to off-gas but in a small amount. According to the U.S. Green Building Council, oil-based finishes can release VOCs for months or even years. Some lower-VOC, water-based finishes largely finish off-gas within a few days but they can still release small amount of VOCs after. Therefore, you should choose finishes that have the least VOCs possible if you want to minimize VOCs released into your home.
Let’s take a look at different types of finishes available for each on-site and pre-finished hardwood.
On-Site Hardwood Finishes
Since on-site hardwood finish is applied, dried and cured on-site, you will have to wait until this process is completed before using the floor. Each type of finish has different levels of volatile compounds (VOCs). Let’s take a look at some on-site hard wood finish choices available.
Oil-based polyurethane is solvent based. It takes a lot longer time to dry (8 to 10 hrs) between coats but it requires less coatings than water-based polyurethane does. It is extremely durable. However, oil-based polyurethane contains high VOCs and strong smell. Oil-based polyurethane can off-gas for months or years even after finish off-gassing after curing. It has an amber tint when applied and the color will yellow over time when exposed to the light. You can choose sheen such as glossy, semi-gloss, satin or matte. You can read about different sheen types below.
This is probably the most popular hardwood finish choice. Water is used as an ingredient of the polyurethane finish rather than the solvent. Therefore, it contains less VOCs in the finish and has less odor. However, polyurethane is still petroleum-based and it contains diisocyanates. Diisocyanates can cause breathing problems, irritation of skin & eyes, respiratory irritation & sensitization. People can be exposed to this chemical by inhalation or dermal contact. However, water-based polyurethane is a much more non toxic choice than oil-based polyurethane. It has faster drying time (about 2-4 hrs) compared to oil-based polyurethane and it finishes off-gassing largely in a few days. However, it requires more coats than oil-based polyurethane does and it is also more expensive. Water-based polyurethane has a clear coat, therefore, the wood floor will appear clear without amber tint that oil-based polyurethane has. This clear coat will remain clear for the lifetime of the hardwood floor. You can choose sheen such as glossy, semi-gloss, satin or matte.
If you are finishing the floor yourself, here are some low VOC, water-based floor finishes.
Safecoat Polyureseal BP is water-based woof floor finish. It is formaldehyde-free and includes no acetone, ammonia, solvents or harmful ingredients. It has very low odor ad very low VOC. It is available in matte, satin and gloss.
Vermont Natural Coatings PolyWhey water-based floor finish has low odor and low VOCs. It is also made from renewable resource.
Acid Cured finish is one of the most durable finishes. Although it is extremely durable, it has very high volatile organic compounds (VOCs). It can take up to 60 days to fully cure.
Moisture -Cured Polyurethane
Moisture-cured polyurethane is also extremely durable. However, it has extremely high VOCs.
Natural Oil Sealer
Penetrating oil sealers such as natural oil sealers are made from linseed oil and pure tung oil. They penetrate wood and harden. This is the most non toxic finish option. It also has very mild odor. However, natural oil sealers are not as durable as polyurethane finish. It wears down over time so it is usually recoated every 2-3 years. It has long drying time of 24-48 hrs. It has a low-sheen matte finish. Although natural oil sealers may need re-coating more often than polyurethane finish, it its easier to repair damages. You can easily re-oil the problem area with natural oil sealers whereas with polyurethane finish, whole section or entire floor may need to be recoated, not just the problem area.
If you are finishing the wood floor yourself, here is an example of natural oil sealer.
Rubini Monocoat Oil Plus 2 C This is a natural wood floor finish and it is made of linseed oil. It has zero VOC and doesn’t contain any water or solvents.
OSMO Polyx Hard Wax Oil is the original Hardwax Oil from all natural oils and waxes. There are matt and satin finish. Ingredients include 2 natural waxes (carnauba and candelilla) and 3 natural oils (sunflower, soybean, and thistle).
Pre-Finished Hardwood Finishes
Most pre-finished hardwood floors have polyurethane finish. Pre-finished solid wood with a natural oil finish is available but it is not easy to find. Therefore, if you want to use natural oil sealers, you may have to get solid hardwood flooring unfinished and have it finished on-site. Let’s take a look at different types of finishes available for pre-finished hardwood flooring.
Urethane Finish With Aluminum Oxide
Most pre-finished hardwood floors have a urethane finish with aluminum oxide. Aluminum oxide is added to the oil-based or water-based urethane finish to make it more durable against normal wear. Most often, urethane finish is cured with ultraviolet (UV) light then aluminum oxide is added to the urethane finish. Pre-finished hardwood floors with aluminum oxide have longer life expectancy and usually comes with 25-35 year warranty on residential wear. When hardwood is pre-finished at the factory, factory is able to put multiple coats of finish applied to wood’s surface fast. The finish is a lot thicker and a lot more durable than the finish done on-site. Therefore, aluminum oxide urethane is more durable than on-site finished polyurethane. A floor finished with polyurethane after the floor is installed typically has a life span of 10 years. Aluminum oxide is more resilient against scratches and it will outlast other finish options. However, this doesn’t mean no cleaning or maintenance is needed. Although a floor with aluminum oxide is more resistant to normal wear, you should be still careful with moisture and damages from furniture as with any wood floor, to keep the floor in best condition.
Pre-finished hardwood planks are finished at factory. You don’t have to wait for finish to be applied, dried and cured since this process has been done at the factory. Therefore, you avoid large off-gassing of VOCs or odors that happens during this process. Aluminum oxide is a naturally occurring element. I have not found any evidence that aluminum oxide finished floors are hazardous. Pre-finished hardwood planks are often UV cured which are cured instantly with UV lights. Since it is cured instantly at the factory, you don’t have to worry about fumes or odor emitting from finish. In addition, it is often well-tolerated even by chemically sensitive individuals according to Green Home Guide. However, studies show that aluminum oxide can be harmful when inhaled. This can be a concern when you have to refinish your hardwood floor since the floor is sanded first before applying refinish coating. If the flooring has an aluminum oxide coating, it will release aluminum oxide particles and dust when it is being sanded. Hardwood flooring with aluminum oxide coating is very durable and it will last for a long time. Therefore, you may not have to refinish the floor. However, when you have to, sanding will release aluminum oxide particles.
In addition, some manufacturers add nanoparticles of aluminum oxide in their finish. Although nanoparticles of aluminum oxide increases the durability of finish than bigger sized aluminum oxide, inhaling nanoparticles can be potentially more damaging to lungs. However, nanoparticles of aluminum oxide is less hemolytic than other oxide nanoparticles.
Titanium oxide can be added to a polyurethane finish to make it very durable. Titanium oxide makes the finish the most durable finish available. Titanium oxide usually has a 25-35 year warranty on wear depending on the manufacturer. It is transparent so it doesn’t change color and it also protects wood from yellowing caused by sunlight.
Is titanium oxide safe? Titanium oxide is also a naturally occurring mineral. It is non toxic, however, inhaling nano-sized titanium oxide can be harmful. Inhaling nanoparticles of titanium oxide can cause pulmonary inflammation that may lead to fibrotic and proliferative changes in the lungs. Nano particles of titanium is also classified as possibly carcinogen to humans by the International Agency for Research on Cancer (IARC). Most products with titanium oxide do not use nano-sized titanium oxide particles but some products such sunscreens make the size of titanium dioxide nano-sized to reduce the white appearance when applied on the skin and have UV protection effect at the same time. There are a few manufacturers offering titanium finish hardwood planks. I am not sure if all wood floor finish with titanium oxide use nano particles but I have seen wood floor finish that contain nano particles of titanium oxide. It is possible that nanoparticles from the coating can release during the floor’s life cycle. However, incorporating nanoparticles into the product is relatively new, there is little information is available how they could be released or how they can affect us in a long term. One study I have found reports that nanoparticles got released and found on the surface of the wood after abrasion of nano coating in both water and in air. Could mechanical actions such as scratching, walking with shoes, movements of furniture and mopping on the wood floor with nanoparticles of titanium oxide can have a long term health effects? It is something to think about.
5. Decide On The Type of Sheen.
Sheen is a gloss level of your floor’s finish. It reflects light and shows the level of shine on the floors. Hardwood flooring finish will usually have a choice of sheen. The options include Glossy, Semi-Gloss, Satin, and Matte sheen levels. Glossy is most shiny and matte is least shiny. High gloss sheen will give the hardwood floor more shine and gloss. However, it will show scratches and dusts more easily, therefore, it requires more maintenance. Low gloss sheen such as matte shows fewer scratches and dings, therefore, it requires less maintenance than high gloss sheen. Glossy sheen will not be ideal for high-traffic areas since it will show the imperfection of the floor and dusts more easily. Matte will be more practical for those areas.
Check out Glossy hardwood flooring products.
Check out Matte hardwood flooring products.
Check out Low Gloss hardwood flooring products.
There are many things to consider when choosing a solid hardwood flooring. There is no one perfect option. Hardwood floor finishes can emit volatile organic compounds (VOCs) which is harmful to our health. Therefore, we should avoid VOCs as much as possible. There are other things to consider like installation, durability, maintenance, repair and style of the floor. These will depend on how much you are comfortable with each choice of these criteria. You would want to choose the most non toxic finish and installation method but also options that offer durability and ease so that you are comfortable with the hardwood floor’s maintenance and repair. Also, please remember no matter what type of solid wood, finish or installation method you choose, at the end solid wood can all get damaged if it is not cleaned and maintained well. Therefore, it should be taken care of like a piece of fine furniture. In addition, ventilate the living space as much as possible in case of any volatile organic compounds (VOCs) being released after newly installed hardwood floor.
If you would like to find out about non toxic wood flooring options, please read my post, ‘Non Toxic Wood Flooring For Your Home – Which Wood Flooring Is Non Toxic?‘
If you are interested in non toxic mattresses, please read my post ‘Non Toxic Mattress Guide – Chemical-Free, Organic Mattress‘.
For non toxic sofa companies that you can shop from, please read my next post, ‘Non Toxic Sofa Guide – Which Sofa Brand Is Non Toxic?‘
Read my post ‘Non Toxic Dinnerware – Which Dinnerware Is Lead-Free?‘ to see how dinnerware can be toxic and what non toxic dinnerwear is available.
If you are interested in non toxic cookware, please read my previous post, ‘Non Toxic Cookware Guide – What Is The Healthiest And Safest Cookware?‘
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