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Flooring is a significant and costly investment in your home. It stands to reason that you're going to want to make sure the installation process goes smoothly and flawlessly. One thing you might have heard about when researching the process of laying hardwood floors is the occurrence of gaps. But should these gaps be occurring in new hardwood floors? We have researched this subject and compiled the results for you down below.
Gaps in hardwood floors occur with relative humidity (RH) changes due to the wood losing water and constricting. This frequently occurs over the winter months as more heat is used to keep the home warm. This increase in heat usage dries out the air, reducing the RH and causing the wood of your floors to constrict. This causes gaps to occur. There is no cause, however, for gaps to appear in newly laid floors. If your new floor has gaps in it, improper installation or misreads of moisture levels are a likely cause.
Wood floors and their relationship to the RH of their surroundings is a dynamic relationship that requires further explanation in greater detail. Let's continue to look at how humidity plays a role in your hardwood floors, but only if you let it, and only over time.
Humidity: Absolute vs. Relative and why it matters
When it comes to gaps in your hardwood floors, there is only one thing to consider; humidity. One of the things you might not realize is that there are two different things one could discuss when discussing humidity. Absolute humidity and relative humidity are not the same concepts. Knowing the difference will make understanding the effect the RH of your house has on your wood floors.
Absolute humidity is described as the amount of water vapor in a unit volume of air expressed in kilograms per cubic meter. Of important note is that this amount does not change with temperature. When the amount of water vapor found per cubic meter is high, so is absolute humidity.
The concept of relative humidity differs from that of absolute humidity in a critical way: it changes with the temperature around it. Relative humidity is the percentage of water vapor in the air at a given temperature and the amount it can hold at that same given temperature. Water vapor in warm air results in a lower RH than that in cool air. This is why hot days are generally more humid than cold ones.
For this article, the humidity mentioned will always refer to relative humidity, as it's the one both we and our surroundings can affect. And it also has a direct impact on our home's wood floors.
Wood is unlike most other materials we use to build our homes. Concrete, stone, metals. None of these are organic materials that were once part of a living thing. Wood differs from all these in how it dynamically reacts to its surroundings. Namely, relative humidity. Wood can, and will, adapt to changes in moisture in its surroundings in ways no other material will.
Do hardwood floors expand and contract?
Wood is a fairly sensitive material when it comes to humidity. When there is more water content in the surrounding air, your wood will expand. When there is far less, it will contract. The reason for your wood floors doing this becomes apparent when you consider the function of a tree. This is true of any wood you use in your house. From cabinets to trim, all wood will react to changes in RH in this manner. It's simply the nature of the material.
When do gaps generally occur most?
As mentioned before, RH is temperature dependant, unlike its absolute counterpart. Hot, muggy summer days are overwhelmingly more humid than colder days found in autumn and winter. Many homeowners don't realize just how dry their homes are during the cold winter months. This is, of course, compounded by heating systems further drying out the air in your home.
Of course, the weather found where you live always stands as another contributing factor to consider when facing this issue. Some areas don't have to deal with humidity, being drier climates. Some areas have persistent but consistent humidity that can be accounted for when installing. But for some, major swings in humidity are a genuine issue when winter and summer change hands.
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Gaps In Your Floor: Solutions and Prevention
There are two things a homeowner can do when it comes to gaps in their hardwood floor: repair and prevention. We'll look at what to do in both of these situations to keep your wood floors as best you can.
Your floor has gaps. What can be done now?
So your floor has developed gaps. Removal and replacement technically would solve the problem but doesn't stand as the most feasible of solutions. Luckily for you, there are some far more cost-effective methods of filling in gaps that have appeared on your floors.
An important tip is to act quickly when gaps and cracks start to appear in wooden flooring. Smaller gaps and cracks are logically cheaper and easier to fix, and floors do get to the point of no return. If you allow your floor to get into an advanced state of disrepair, total replacement might be your only option.
Wood Putty and Wood Filler: What are the differences?
When looking for gap filler, you're likely to hear two of the products are wood putty and wood filler. They might sound like interchangeable products, but there are key differences that make one preferable over the other in various situations.
Wood filler generally contains sawdust or wood fibers suspended in a binder. Putty, on the other hand, usually contains plastic such as epoxy, fiberglass, or polyurethane. Unlike filler, putty doesn't harden after application. Putty is, however, weatherproof and therefore much better suited to outdoor use than filler.
Filler also better suits indoor repairs in terms of aesthetics. Where putty is much more utilitarian, a filler is usually tinted to match various wood shades. It is meant to be coated with a clear finish after filling in space and make indoor floors look closer to their original state before gaps occur.
How to fill in gaps
When it comes time to fill in gaps, you'll first want to make sure the gap is clean of any debris. We'll be considering inside repairs in this article as outside repairs can generally allow similar but rougher repairs.
Using either a putty knife or your fingers, apply enough product to allow a gap overfill. Once it dries, use fine sandpaper to smooth out any rough edges. Add more product if necessary and any stain to match your floor color if desired.
If bigger gaps have been given to form, and total replacement isn't feasible, there are some options. You can use narrow strips of wood called wood shims to fill wider gaps when putty or filler would be too much. Place these shims when the weather is at its most humid and gaps are at their smallest. This will keep your repairs from cracking when they expand. Finish by sanding and staining to match your existing floors.
How do I prevent gaps in my hardwood floors?
We've gone over a few fixes, but as mentioned, the best thing you can do is prevent gaps in the first place. The best way to go about doing this is to do your best to keep the RH in your house as stable as possible. If there aren't huge swings in relative humidity in the air around your hardwood floors, they will shrink and contract far less. Try to counteract the humidity of the outside weather as best you can.
The ideal RH for hardwood floors is around 50%. During drier months, you can use humidifiers to help maintain an ideal RH level. Likewise, dehumidifiers can achieve the desired opposite effect. It's an effort, but the investment of a hardwood floor requires your effort if you want to keep it looking good.
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A final reminder
Wood will expand and shrink; it is the nature of the material you are working with. However, this is a process that takes time to occur. There should not be gaps and cracks in your floor instantaneously upon installation. That speaks to other problems with materials, installation, possibly the subfloor upon installation. If you notice issues soon after installation, call your handyman and search for answers. Something went wrong.
Wooden floors are an investment; you have to be willing to put time and care into them along with the money. The best solution to cracks is always going to be prevention. Take the time, and your floors will stay beautiful for years to come.