Definition:
Site finished flooring is referring to a wood floor that is sanded and finished after it is installed.

This method, as with any, has it’s pros and cons:
Advantages

1. The end result is smooth across the entire surface of the floor with no detectable high/low points
2. You spend less money on the wood itself than you would on prefinished wood
3. Any conceivable borders, fancy inlays, or other carpentry tricks can be employed

Disadvantages

1. The finish is not as hard as that of a prefinished floor
2. Initially, the finish will have many small bubbles/imperfections. These will fade in 2 to 4 weeks
3. The sanding process creates a lot of dust that gets everywhere
4. The finishing process creates a powerful odor (in most cases) which can linger for several days/weeks (The odor is only strong for the first day or two)
5. The entire installation takes around twice as long as it would with prefinished, costing you more in labor
6. Because of the finish, you will be required to stay off of the floors for as long as 48 hours from the time the workers start to apply the finish
7. Heavy furniture will need to remain off the new floors for at least 48 hours after the last coat is applied

What to expect

Doing Your Part. Although many hardwood guys will take care of some of this (for a price), it is generally considered your part of the job.

Site finished floors must be sanded and finished all at once, whereas prefinished floors can be installed room by room. So for the sanding/finishing, all furniture, cords, curtains, closet doors, etc. will need to be off the floors. Any pets, children or guests will also need to be kept from wandering onto the floors.

It is also your job to decide whether you will need to live somewhere else for the installation, sanding, and/or finishing processes. One reason you would need to live somewhere else is if every entrance/exit to the house is going to be cut off by new wood. If that is the case then it would be best for you to be out of the house for the entire finishing process since otherwise, you wouldn’t be able to leave. This is all basic common sense, but is sometimes easy to overlook. Be sure to talk with your installer about when you should/shouldn’t be in your house.

The Sanding. This step is what causes the most mess. Sanding creates sawdust. Fine sanding creates fine sawdust. This sawdust gets everywhere.

If you want, the installers can mask off the area that is going to be sanded (for a price). This will keep most of the sawdust out of wherever you don’t want it to be. Keep in mind that the only way to keep all sawdust out of an area, is to make an airtight seal.

Sometimes, installers will have vacuum systems on their sanders that will eliminate 90 percent of the dust. But don’t be fooled, there will still be dust and it will still get everywhere. The only exception is a very expensive vacuum system that requires a large vacuum trailer. Installers with these systems usually charge more to offset the cost to run such a machine. It is in your best interest, if the dust is a problem, to arrange to be out of the house during the sanding.

The Finish. This is the most sensitive part of the entire job. There are a lot of things that will affect the drying time and overall quality of the finish. Some of them are Humidity, temperature, air movement, and presence of direct sunlight.

Although it is nice when the finish dries faster than it is supposed to, this can cause quality problems like bubbles and overlap marks. Please be in communication with your installer about any decisions you make that will affect the drying time/quality of the finish.

The Finish (Odor). Oil-based finish emits very powerful (and not at all healthy) fumes for the first 8 hours or so. The smell may stick around for up to two weeks after the floor is completed, but will be significantly dilluted, and not at all harmful. A common mistake that homeowners make is to immediately open windows and doors after the installers leave. This can cause many problems having to do with air flow if the floors are still wet or tacky. Once the floors are dry, however, feel free to air out the house however you choose.

The Finish (Air flow). As a general rule, airflow over a wet floor is bad. Air movement moves dust, dog hairs, and other impurities… and as luck would have it, it moves it all right onto the floor. Now, it is impossible to stop all dust, hair, etc from getting into the finish during the 6 or so hours that it’s wet, but it is possible to cut down on it. Please talk to your installer about things like windows (Which should generally be closed), furnace vents (which should be blocked or the furnace should be off), and any kind of fans or air-moving devices.

The Finish (immediate result). Immediately after the floor is dry and you check it out for the first time, you will notice something about the finish: It’s not perfectly smooth! This is because your house is not a perfect (or even a very good) environment for applying finish. Floating around in the air is dust, pet hairs, and many other impurities that will settle into wet finish. There will also be several bubbles scattered about in the finish. This is normal and unavoidable. But fear not! Most (if not all) of these small bumps and imperfections will get smoothed out in around 2 to 4 weeks of people walking on the floors. After a couple months, your floor will be about as smooth as any floor you’ve seen.

The Finish (Drying time). With an oil-based finish, it is usually safe to walk on your floor as soon as it feels completely dry (about 8 hours). However, take note that it can take as long as 2 or 3 weeks to be completely cured. So it is good to wait as long as you can (up to 72 hours) to put heavy furniture back on the new floor.

The Finish (Water-Based). Water based finishes are getting better and better as technology advances. The immediate and obvious disadvantage is cost. A good water based finish can cost 5 times as much as its oil-based equal. The advantages are that there is virtually no odor, and the drying time is significantly lower (2 hours instead of 8, and 24 hours to get completely cured instead of 2-3 weeks). It is also more difficult to apply, so make sure your installer is comfortable with applying water-based finish before deciding on it.

The Finish (conclusion). Just remember not to expect a furniture finish. Be sure to talk to the installer about any possible concerns you have before the finish has been applied. This gives him/her a chance to fill you in on all the possible problems that are common to your situation.

Nail holes/heads. The installer should set all nails and fill all holes. As a result, there should be no visible nail heads or nail holes. However, if you kneel down and look closely, you should be able to find where the nail holes used to be, because no wood filler (or wood putty) can be a perfect match to a wood grain.

Also, there should only be a few nail holes in most floors. In fact, most of the time, a simple, square room can be installed without any nail holes at all. But keep in mind that many situations will require a board to be top-nailed, resulting in nail holes.

Cracks and Creases. Any time a board comes together with another board, it forms a crease. These creases are what make hardwood floors look how they do. On a site finished floor, if you close your eyes, you should not be able to find these creases. When you slide your bare feet across the floor it should feel like the whole floor is one peice of wood. One or two slight imperfections in this area are acceptable, but if it is possible to stup your toe, or even catch your sock on one of them, the installer should sand it smooth and refinish that area at no additional cost to you (if it was his/her fault).

When you look at a hardwood floor, there are the creases that go along the length of the wood, and go all the way across the floor (with the grain), and there are small creases inbetween boards in the same row (against the grain). The smaller creases, as a general rule, should be fairly evenly distributed around the floor, with none coming within 6 or 8 inches of eachother. Seams that are close together, or clumped in one area, leaving another area somewhat seamless, are the signs of a poor installation job. They are not, however, a good enough reason to demand that your floor be ripped up and reinstalled at the installers expense. Usually in those cases, you’ve hired a very inexpensive installer, and you got what you payed for. If it is a big deal to you, you might talk about getting the floor redone at a discounted cost.

Any crease in a wood floor has a chance of becoming a crack, for various reasons. One may a milling imperfection in some of the boards (such as one board being slightly thinner than another). Expansion and contraction may be another reason. In general, wood will expand in the summer and contract (shrink) in the winter. This causes gaps to open up between boards. It is not always good to fill these cracks, because when the boards expand again, it could push the filler out, or even buckle the wood.

On the other hand, cracks that are caused by milling imperfections or installation mistakes/problems, should be filled by the installer (with the possible exception of smaller cracks if significant expansion is expected after the installation).

After installation, there should be (in most cases) no visible cracks when viewed semi-casually from a standing position (and without a magnifying glass, please).

Scratches, gouges and other surface problems should not be visible when the installer is done. If the board was damaged when it arrived at your house, the installer should not have installed it. If it happened after the installation, but the damage was caused by the installer, he/she is responsible to fill it, fix it, or replace the boards affected. If, however, the damage is caused by another contractor or worker, or any residents, guests or pets in the house, the installer is not responsible to fix it, and is perfectly within his/her rights to charge extra if you want it fixed (However, charging extra to fix one small scratch that he/she can fix in two minutes, may be considered a little rude).

Expansion Gaps. Because wood expands and contracts (due mostly to changing humidity and temperature), installers will leave expansion gaps between the wood and everything else (walls, other floors, etc.). In general, these gaps are between 1/4 inch and 1/2 inch, and are concealed by the baseboard. However, this can create a problem sometimes on remodeling jobs, especially in kitchens.

Many houses do not have any trim (or baseboard) around the bottom of the cabinets in the kitchen. When wood floors are installed in these conditions, there will be a visible, ugly expansion gap left over. The homeowner should work with the installer to select (and pay for) a baseboard, trim, or caulk solution.

Baseboards. It is common for the installer to remove and reinstall baseboards when he is hired to install a floor (for a price that should be included in the estimate). This can sometimes cause problems with older baseboards. The installer is responsible for any damage done to the baseboards due to his/her own negligence or hurriedness. The installer is not responsible for any damage that already existed, or that occurred because of the brittle state of the baseboards or excessive fastening to the wall (ie too many nails and/or glue). Be prepared to deal with at least one broken peice of baseboard. Many times the damage can be fixed with a little painter’s caulk and a coat of paint, so don’t get too broken up about it.

In conclusion, please remember that it is a floor and it’s meant to be walked on. If you get down on your hands and knees and study the floor, you will find cracks, holes, scratches, and many other imperfections. When inspecting a floor, it should be done from a standing position in normal light. If you can see problems from that position, that is when you should point them out to the installer. People who refuse to pay because of common imperfections that are expected in wood floors are setting themselves up to be blacklisted or overcharged by other contractors in the future. Nobody wants to deal with an unreasonable customer.

And if you happen to be in Colorado Springs, check out Hardwood Floors by Thomas (formerly “Hardwood Cafe”) for great flooring info, advice and even installation.