Cottage Floor Help

[1750]

My cabin is on the shores of a lake. In April '11 there was a flood and we had 16" of water in the cabin. I had buckling down the center of the cabin where the floor was pushed up when there wasn't anywhere else for it to expand to. It went back down as it dried out, but it really took around 2 years to get enough air over and under it to do it. Having the subfloor and such is working against you in this case.

Maybe you can pull it, sticker it and let it equalize and it will flatten out again.

Good luck.

Matt

Thanks, Matt. That's the second time someone has used the term "sticker" in this thread. What's that mean?

I bought a dehumidifier this week and have had it running for a few days. The relative humidity went quickly from 65% to 50% -- which is what I set the dehumidifier at. There was a slight improvement in the cupping -- but I bet it will take time for the wood to give up it's water. The ceiling below the wood floor is drywalled and painted, so I'm guessing it may take quite a bit of time for this to resolve.

At this point, I'm planning on taking the floor up and reinstalling with new expansion gaps. I think the humidity will always be on the higher side, but I'm feeling like it's mostly relative to the humidity that exists when the wood is acclimated and installed.

Thanks again.

 

[EatenByLimestone]

Stickering is putting small pieces of wood between the floor boards to allow air to move around it. Make sure the boards are supported on both sides by stickers so they do not warp.

(broken image removed)

The problem with running a dehumidifier is that you'll eventually turn it off and then the boards will absorb moisture again. The best bet for the floor to last is to let the boards acclimate to the local climate. When a tree is cut and processed into lumber, they figure a year for every inch of thickness. If you can, you would probably be well served to pull it up and let it sit over winter if the cabin is only used seasonally.



My flooring absorbed a lot of water when it sat under water for a few days. It still has a few low peaks where it never went back to flat. It took a good 2 years for it to dry out. I have the upper surface painted but the lower side of the floor is open to air moving below the cabin.

Matt

 

[EatenByLimestone]

I miss that picnic table. A friend took that pic. When I visited the place the next day it was gone.

 

[1750]

Wow, that's quite a flood. It doesn't happen often, I hope!

I put the dehumidifier in there just to make sure I could draw down the moisture if I wanted to, and to see if it had a noticeable effect on the flooring (after a few days there wasn't much if any difference).

Also, I found this publication from the National Wood Flooring Association that was really very helpful for me to understand this, and also quite consistent with most of what folks here said. Here's the link in case anyone is interested:
http://www.goldenstateflooring.com/documents/waterandwood.pdf

There's a table in the pdf that shows what woods tend to move the most with changes in moisture levels. According to the table, maple is one of the bigger movers. There is also a description of a situational variable common to cottages that probably really applies to me (and maybe others here, as well):

RELATIVE HUMIDITY: When humidity increases, the effect on the wood floor can be damaging. This occurs most frequently in homes in which occupants are there for a short period of time, such as a week- end home or vacation cabin, or in rooms that are closed off (not heated) to save energy.

If air conditioning or heating is not used or is shut off, ventilation is a must even when the home is not occupied. Otherwise, the floor will expand in the high humidity, and cupping and buckling will occur. This “greenhouse effect” will be exaggerated even more when a plank floor has been installed, because wider boards react to moisture with more movement.

In addition to being able to dial in the desired RH, the dehumidifier I bought has a timer on it. During the summer, rather than running the dehumidifier while we were away, I thought I could play around with setting the timer for a couple of hours after we leave to pump out humidity we drew in while opening the house up. Regardless, I think the wood must be pretty well acclimated now (it's been down for about 9 months). If I can get the floor relayed in the next couple of weeks with new expansion gaps, I think it would be in the middle of it's typical zone and should be able to expand and contract in response to typical fluctuations for the region. I also might consider just leaving some windows open during the summer to allow the house to breathe a bit more.

Finally, this was amazing to me:

GROWING BOARDS - How much can temperature and humidity affect the dimensions of a hardwood floor? Take a look at one 5-inch red oak plank board:

1) Within “normal living conditions” (say, an interior temperature of 70 degrees and a relative humidity of 40 percent), the board has a mois- ture content of 7.7 percent and is 5 inches wide.

2) If the relative humidity falls to 20 percent, the moisture content of the board will be 4.5 per- cent, and the same 5-inch board will shrink by .059 inches. Across 10 feet of flooring. that could translate to as much as 1.4 inches of shrinkage.

3) If the humidity rises to 65 percent, the board’s moisture content would be 12 percent and the same 5-inch board would expand by .079 inches. Across 10 feet of flooring, this could translate to 1.9 inches of expansion.

Almost 2 inches across 10 feet! No wonder my floors are buckling....

Thanks again to everyone for your help working through this.

Mike

 

[1750]

To me the biggest problem with relaying the floor is dealing with the old nails.

Rather than pulling them all out, does anyone see a problem with just using some end cutting pliers and nipping them off?

Thanks!

 

[EatenByLimestone]

This would depend on if they are face nailed or nailed through the tongue. I'd probably try fitting a wide, flat bar under an end and trying to work the whole thing up. Then tapping the nails back out from the back. I'm not sure how it would work, I've never done it before with nice flooring, but this did work for T and G attic planking. If you can't get in from an edge, you may have to destroy the groove of one row in the middle so you can get ahold of enough wood to pry on.

Matt

 

[1750]

This would depend on if they are face nailed or nailed through the tongue. I'd probably try fitting a wide, flat bar under an end and trying to work the whole thing up. Then tapping the nails back out from the back. I'm not sure how it would work, I've never done it before with nice flooring, but this did work for T and G attic planking. If you can't get in from an edge, you may have to destroy the groove of one row in the middle so you can get ahold of enough wood to pry on.

Matt

I'll try that. These are staples so they don't have the rigidity of individual nails.

Thanks again.

 

[RevRon]

Perhaps this has already been mentioned but, you say you installed the floor in the winter? Winter is typically the driest time of the year. Even if you acclimated the flooring before installing, it would still be installed at a low humidity level. Once humidity levels start to rise the flooring would have expanded and maybe causing some cupping. Typically hardwood is not installed in the winter.