RH and moisture readings before installation

Q: I installed hardwood flooring on the main level and the top level of a new home as well as a hardwood staircase. The install was in Nov 2013. The floor on the main level is showing areas of gaping and splitting and so is the staircase. There is a lot of shrinkage in the trim and mouldings as well as some shrinkage in the kitchen cabinets and the solid wood cupboard doors in the same areas of the house.

The RH at the time of install was in the 40% range and the wood was in the house for at lest 72 hours before being installed.

The present moisture reading in the floor on the main level where all the problem is are 9 to 8 and up to 12 in some areas; the stair treads have different readings one is 7 and the next one is up to 13. When we take a reading in the basement of the floor and the sheeting for the first floor the meter does not give a reading because the level is too low for the meter to read. I have developed the basement and added a propane stove in the last year. The ceiling is a T-bar type with a drop in tile. Did this cause the staircase and the floor on the main level of the house to react in this way? The RH at present on the main is 38% and the basement is 30%.

A: It sounds to me the moisture reading of the wood products were not taken prior to installation. At any rate, significant heat rise coming from under the stairs and floors could significantly dry the areas you mention. You could add some moisture to the air, but 38% is not bad at all in winter, and I don’t think you would want to go much higher. It is possible none of the wood, stairs, floors, etc., were dry enough, or dry enough to be within range of 4% moisture content in the sub structure.

Related Q: I had hardwood floors installed about four years ago. Last year they started popping and making loud creaking noises without having been walked upon. This causes my dogs to freak out during the night and they react as if thunder were occurring. The dogs are pacing and panting and unable to settle down. The floors were acclimated. They are tongue and groove hardwood hand scraped. This didn’t start until the third year. Last night it started again big time! I am thinking it has something to do with the air conditioning that is running 24/7 now! Is there anything I can do to alleviate this problem? Perhaps removing a board in an inconspicuous spot? It happens on the side of the bed under the windows and there are two air directional openings there on either side of the room! This is only in the bedroom even though the floor was installed through the living, dining room, kitchen, and hallways. Can you help me? Limber Liquidators acts like they never heard of hardwood floors. It cost me a bundle to have them installed.

A: Check the moisture content of the floors and also the relative humidity. Do you notice anything else with the floor? Cupping, gaps between boards?

Follow-up Q: What should be the proper humidity and moisture content? And how would I check for moisture content in the wood? Is there something I can add to the wood floor to make it better? It has not made the huge cracking noises for the last few nights. It was one night that it was going on all night. And I believe it was only one or two nights last year this time. But it is always crackling when I walk over there to shut the drapes every night. I don’t mind that so much. It is the popping for no reason when we are in bed and it is freaking out my dogs on each pop! The floors look beautiful. I cannot see any cupping or gaps anywhere! Thanks for your advice.

A: Moisture content in the flooring should be 7-9%. If it is up to 15% or above, there is a problem. If it is very low the wood will certainly contract. Relative humidity in the room I would say should ideally be 40-45% RH. Of course, in cold climates you can’t have that high of a reading in winter or you would have water running down the windows and walls. If it is only one or two spot that make a noise when you walk on it, is there any up and down flex in the floor? Maybe there is a dip in the sub floor with a hollow spot. If that is the case, you wouldn’t have good penetration of cleats or staples.

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