I posted a series of questions two weeks ago and Gary was kind enough to answer them. Here I am again with a few more.

I am preparing to lay 2200sf of 7.25" T&G plank flooring in a new home. Today I went up to start the job only to find the subfloor (3/4" plywood) was still reading 12-14% moisture. The plank flooring on the other hand is reading 7%. It has been in the house for 10 days.

My plan is to blast the house with heat and dehumidifiers for another two weeks and then try to lay the flooring. [There is a bit of pressure on the situation because my wife is due to have our first child in four days and we are stuck in a very small rental house until ours is finished.]

Can I ask two things:

1) What is a reasonable difference between subfloor moisture levels and flooring moisture levels? I am told 2% but what if I can't get them to that?

2) What is the best way to finish soft woods like pine? I am thinking of Danish Oil or Stain and Tung Oil.

Thanks.

Christopher.

#1) a 7% MC is too great of difference. Have you taken all the steps to ensure moisture is not entering the crawl space and living space? Have you been painting or doing tile or drywall? Do you have a quality moisture meter? Test the underside of your subfloor and test the floor joists. If your readings are getting higher, the moisture is entering your crawl space. With a 7% MC in your flooring, anything over 10% in the subfloor would be risky. If you cannot wait floor the flooring and subfloor to reach equalibrium, then I suggest full spread gluing of your planks with Bostick's Best and using their MVP first. It will increase the cost but block most of the moisture transmission.
#2) For Pine floors, you can use a surface coating (oil-based polyurethane) but many manufacterers recommend Waterlox. Each type have their pros and cons. I would stay away from glossy finishes.

Thanks again Gary. I now have two heaters running in the house (2500sf) and, as of today, one large fan. I also have three dehumidifiers running. The temp in the house is 80 degrees upstairs and about 85 degees downstairs. After three full days of this I seem to have lowered the average moisture level of the subfloor by .5 percent. I am hoping to dry it like this for another week and a half and then lay the flooring. The flooring planks now range from 6 to 8 percent.

Can you tell me what things I might do to speed the acclimation. Would it be helpful to drive the temp up any more? I have another box heater that would probabaly push it up to the ninties. Should I be leaving any windows open? There is some air inflow on the first floor. Should I allow some to escape on the top floor?

As to your last post, the crawlspace still has a large dehumidifier in it and two big fans. It is much dryer that two weeks ago and now looks and feels dry. The moisture meter still reads about 32 percents down their though.

Thanks.

Christopher.

I think you are going about this the wrong way. When you say, "The moisture meter still reads about 32% down there though." What are you refering to? Are you saying that your floor joists and the underside of the subfloor reads 32% moisture content? If that is the case, put those heaters under the house because that is what needs drying out. You are cooking the interior of your home. So turn the heat down to about 70 deg. and leave it there. Keep your fans going; air circulation is good. Is your pine flooring "stickered"? If you don't know what I mean, then it's not and it should be. Have you put the poly vapor barrier under the house? If not, do so now. Weight it down with bricks, rocks, gravel, chunks of concrete, etc. Do you have foundation vents? You may need more. If I was there, I could indentify and correct the problem quickly. But since I'm not, this is the best I can do. What is the moisture meter reading on the underside of your plywood subfloor? What is the reading of the floor joists? What is the drainage situation around your home? Is there a big hill next to your home? What steps have you taken to divert groundwater and runoff away from your home?. These questions need to be answered. If you install the floor too soon, it will cup and you will always regret it. E-mail me if you like. member list #113 page three.