Article
March 24, 2005
Hardwood Floors
A glossary of common technical terms
I once read an article that described wood in this manner. It said, what if a salesman came to you with a brand new product you could use to build with.
He described it as the perfect material to build a house out of except that it shrinks, buckles, contracts, twists, warps, splinters, curls, burns, blisters, molds, decays, and rots!
Sounds a little scary to say the least. Well fortunately, even though wood does do all these things, if properly looked after it is still a great product that performs for many years when treated appropriately. So when it comes to hardwood, are there any issues you need to be aware of?
First you want to decide what kind you would like. Some woods are harder than others. Some are more stable than others. And what does that mean? A stable wood is less susceptible to either shrinking when the air is too dry or expanding when too humid. Another important question is how will it be finished. The two options are site finished and pre-finished.
What’s the difference? Site finished is as it indicates. The wood is installed, sanded, stained, and finished right in the house. It is a very rich looking product that has a smooth consistent color and finish since there are no lines or joints in the wood that are obvious. At the sanding stage, any imperfections or knots in the wood are filled.
Pre-finished, on the other hand is where the wood is sanded and finished in a factory. This provides a perfect finish done in a controlled environment with controlled conditions. The finish is harder, and lasts longer. The disadvantage is that where each board is fastened together you have a small line or joint. However with each type of installation and finish there are some basic principles that should be followed. One common misconception is that you need high humidity in your home when you have hardwood. This is not always true.
When you choose a hardwood, look for a quality milled material that was properly dried for a dry climate. If the wood is dried to a low moisture level and is installed at a low relative humidity, over a subfloor that is also dry, the requirement for humidity is lower. In fact to maintain a moisture content in wood of 6 per cent, you only need to sustain a 25-30 per cent relative humidity in your home to prevent the wood from both swelling and shrinking.
So the simple rules to follow are:
Acclimatize the wood to your house at the relative humidity level closest to what you will operate the house at. Acclimatize means to get the wood to absorb or release moisture to be at the level where once installed, it will stay the same size.
Pre-finished wood requires less time to acclimatize and don’t cover the wood with plastic or materials that will trap moisture. Also don’t do any work in the house that will produce high levels of moisture, such as pouring the basement concrete or painting. And you also don’t want the other extreme of very dry warm air.
Install the wood over a dry subfloor that has been checked using a moisture meter. Compare the moisture content in the floor to that of the hardwood. They should be the same. If not wait to install until they are. Install pre-finished woods at or near the end of the process, when you install other floorings such as carpet, tile or vinyl.
For site finished, install prior to cabinets. This gives the wood an additional amount of time to acclimatize to reduce changes to the size from either shrinking or expansion. And don’t forget to add at least seven to ten days to the process for site finished. You need the extra time to acclimatize, sand and finish and you will want to put the last coat of finish on just prior to possession but still leave at least 24 hours before walking on the floor.
Hardwood floors are beautiful and last for years. They can be refinished over and over again, even if they were pre-finished to begin with. However don’t forget that a wood floor will move and still shrinks and swells depending on the season. Most hardwood problems are the result of too high expectations or lack of communication about what the floor can and can’t do.
If you’re going with hardwood in your home you need to do some homework as well. You can get so many varieties and colors. You can get select, number one, two and tavern or cabin grade. And don’t forget the most important rule which is very true for hardwood – you get what you pay for, both from the material and the installation.