The deal moisture content, what your calling humidity(humidity is moisture in vapor form) is exactly the same, and real close to what the average moisture content is for your region of the world. And there is a limit for both subfloor and flooring, or mold is a big concern. I shoot for the regional average moisture content, which is 9% in my area of central Texas. If I see a subfloor with 12% or higher, I will not install at all. That is a red flag, here. The rule is 4%MC difference with strip flooring, and 2%MC for plank and any exotic floor. But a 8%MC 2¼ wide board, installed on a 12%MC subfloor, is asking for trouble in my book, unless you leave some minute calculated gaps between each row of flooring. If the HVAC is not up and operational, running to efficiently condition the home, not set at 80º during the summers, or 80 during the winter. You want the HVAC to run efficiently during the summer, to pull any building up of the humidity levels inside the home. With todays home building practices, homes are built much tighter than those just 10-15 years ago, much less 50 years ago. So those tight building practices, actually create a greenhouse out of the home, if there is nothing running to remove the building humidity or even air circulation. Then in the winter you have the heater drying all the wood out, and an air tight home. Your making a kiln. Unless you have something to add moisture into the air, to create higher humidity levels inside the home, the wood will dry out and shrink in dimensions across the face of each board. It can be extreme, depending on the wood species. So, all in all, it sounds like the guy holding up your investment truly cares about what he or she is doing. It sounds like they know what they are talking about, instead of some salesman, telling you what you want to hear. They are not out to make the fast money and run from the problems later. Not every project is the same as another, even if they are the same floor plan, built right next door to each other.

Is am also in the process of installing carpet on concrete floor. I'm turning out finished garage into a "man cave" for my son who just turned 22 over the weekend. I purchased Berber carpeting and a roll of that blue on one side, mint green/rainbow padding on the other. One wall of the garage is insulated (wall covering garage door) other walls are not. No leaks or moisture problem, just worried about how cold it will be in the winter. Garage is 12x20 and he has a very good space heater. Should or do I have to lift the floor up before installing the padding/carpet? Is it absolutely necessary to do this? Single mother of three with two in college and a son who needs his own room, so any suggestions will be greatly appreciated!! Lala

This is great advice, BUT...what if you and your spouse aren't on same page or timetable. My husband is all about the nuts and bolts of construction, but I am trying to be proactive and get some other decisions made about what he deems more "decorator/cosmetic" type stuff...i.e., cabinetry and interior trim/casing, etc. I tried to tell him the cabinets could have a lengthy lead time depending on what we pick, and that BEFORE we can decide on cabinetry, we have to make a decision on appliances. In other words, we can't plan cabinetry around the 25 year old refrigerator he doesn't want to get rid of until it croaks... We should "plan" for the refrigerator we "want" rather than what we "have". I also want a 36 inch rangetop instead of a 30 inch gas cooktop, and that too has go into the planning. I know he's thinking we'll take a wait and see approach - meaning what we have left $$$-wise and then make appliance decisions, but in the real world it doesn't work that way. I've just run into the same issue with the siding on the house - the plans were drawn with hardie board & batten siding to give the project a fresher mountain farmhouse look. Our GC assumed that meant we wanted to paint the siding after installation because my husband really didn't listen to me when I talked about using a rustic prefinished hardie siding. He thought the "rustic" could just be painted on afterwards, and now is crazed because the GC is telling him the local company that prefinishes the hardie has a 3 month lead time due to their volumes, and the other company that does that type of prefinishing is in Canada and the Pacific Northwest and we'll have high(er) freight charges. It goes back to thinking that "painting" is just "painting" and is a cosmetic thing...

The bottom line with engineered in a home with RH fluctuations (too low in winter and possibly too high in summer): SHORTER life span = Guaranteed - Read below: Cupping is likely in summer (ahem...you have a DEHUMIDIFIER in your crawlspace = humidity imbalance is already known) 3. Gapping is GOING to happen in winter (you already know this because your own investigations into your home's environment are already pointing in that direction. "Checking" or splitting/cracking of the veneer surface is HIGHLY probable once humidity drops below 30%....and it can do it year #1 if you have a bad winter! There is NO going back once it does this = need a new floor. 5. Wood does not always "go back" to size once it has been "stretched" too much. Example: a wood floor exposed to HIGH humidity in the air = crowning....if the humidity is left to stay HIGH for months the wood may NEVER go back to original size. This is the major risk. It can happen with engineered and solid. As you can see, an engineered hardwood has many concerns with humidity levels and lack of control. Remember: the weakest link in any chain is the place where metal has been "bonded" together. The "weld" spot can be the weakest spot. That is the same concept with wood. The weakest spots are the GLUED areas. The GLUE can "let go" when exposed to too much movement. Wood is hydroscopic (it grows or shrinks with moisture levels). The HIGH END adhesives can be VERY elastic....but they will eventually "age" and then become brittle and then eventually "snap" - like an old crunchy elastic band. The more the glue is MADE to move, the more likely it will FAIL = delamination; checking/splitting, etc. A solid hardwood is missing all that GLUE. It will have it's issues....but the issues are more likely to stay "healthy" and functional over time. If you do NOT have a "veneer" you do NOT get delamination. If you do NOT have glue, you cannot have glue failures. If you wish to work with engineered hardwood, you might want to look at floating flooring. When the edges are glued together, the floor will move as ONE PIECE. It will expand as one, and shrink as one. There are VERY FEW solid hardwoods that are allowed to be "floated". And only 70% of all engineered are allowed to be floated. At this point, you will need to "pick your poison". You know your home's weaknesses. You know your own tolerances (and you accept the imperfections of "life" which is a HUGE advantage ;-). You will have to find the product that is the MOST APPROPRIATE for your use. You want a floor that will "last" and that will never be refinished (while you are in the home....the next people can deal with the floors later). I worry that an engineered hardwood in a wider plank (4" or greater) will have issues in your environment. The checking and splitting of the top wear surface (the veneer) is a BIG possibility in your situation (with humidity that *could drop to 20% during a cold winter). And that NEGATES the requirement of a LONG LASTING floor. Once that veneer splits, you need a new floor OR you need wall to wall area rugs to stop the 3" splinters from stabbing you in the leg. A narrow plank (3") solid factory finished hardwood that is quarter sawn. Cleat into place so that you avoid the glue concerns. This might be your "best bet". I would install the floor in either spring or fall. We call these the "shoulder" seasons. These are the seasons where the humidity is considered in the "average" range for the home. Not too high, not too low. That gives the wood the best chance of being "happy" for the longest periods of time.