Preventing wood from shrinking

Messages
8,711
Location
Nothern USA
I really love the oak floor in our family room, but every winter the wood dries out, shrinks and gaps open up. Then in the summer, it expands again. Is there anything I can treat it with now before it absorbs moisture to swell it that it won't lose next winter? I put down a whole quart of Liquid Gold yesterday before leaving the house. I poured it on and squeegeed it around letting it run down the gaps to cover the unfinished edges and the bottom side. It darkened the wood and I had to clean the excess off when I got home. If I really thought it would work, I would be willing to do more. Anybody know if it will or anything else that will work? I don't think I can do a whole lot more on the humidity level of the house. The crawl space under it is very dry for a crawl space. I have sealed the water out. The water pipes don't even sweat in the summer time. In the winter, the moisture in the air is high enough we don't get static walking where we have carpet. I have heard of treating old wool with polyglycols. I have no idea where to buy any except brake fluid, and it is toxic. Whatever I do, the floor has to safe for the dog and visiting grandson. Besides, brake fluid strips finishes off.
 
Messages
1,007
Location
Dallas, TX
I guess this is why I like a nice thick coat of varnish on floors. Super shiny and it stabilizes the moisture content. Does the floor have any kind of a sealer on it now?
 
Messages
4,998
Location
Milwaukee, WI
The change in size is due to the changine moisture content in the wood. Things like Polyurethane will slow the process, but not completely stop it. Most of them you will not be able to apply to the underside of the wood floor, though, so they probably won't solve the problem. There really isn't much you can do. Oak moves quite a bit compared to other woods. 10% is not out of the question.
 
Messages
360
Location
Duluth, MN
Besides using kiln-dried wood (which all flooring should be) and using quarter-sawn stock, you're kind of out of luck. The only other thing that might help is putting in a bamboo floor, but I'm guessing you're too far along to consider that! Clark
 
Messages
10,611
Location
Las Vegas NV
 Originally Posted By: bepperb
The change in size is due to the changine moisture content in the wood. Things like Polyurethane will slow the process, but not completely stop it. Most of them you will not be able to apply to the underside of the wood floor, though, so they probably won't solve the problem. There really isn't much you can do. Oak moves quite a bit compared to other woods. 10% is not out of the question.
What he said. Moisture mostly leaves/enters wood through the end grain so sealing the end grain will have the greatest affect. As stated above, Oak moves quite a bit.
 
Messages
1,445
Location
Grand Rapids, MI
For a harder wood, Oak is fairly stable. Just because you don't get static shocks in the winter doesn't mean it isn't too dry. You need a reasonably accurate gage. I put down a lot of Red Oak flooring in my house a few years ago and I don't have any issues. I run the A/C in the summer and humidify in the winter. I try and keep the humidity in the 40-45% range in the winter. If it gets really cold outside and the windows start to sweat I'll drop it to 35%. Do you have a moisture barrier between the crawl space and the floor? That might help. You might be sucking up too much moisture in the summer.
 
Messages
9,564
Location
Ontario, Canada
 Originally Posted By: WishIhadatruck
For a harder wood, Oak is fairly stable. Just because you don't get static shocks in the winter doesn't mean it isn't too dry. You need a reasonably accurate gage. I put down a lot of Red Oak flooring in my house a few years ago and I don't have any issues. I run the A/C in the summer and humidify in the winter. I try and keep the humidity in the 40-45% range in the winter. If it gets really cold outside and the windows start to sweat I'll drop it to 35%. Do you have a moisture barrier between the crawl space and the floor? That might help. You might be sucking up too much moisture in the summer.
+1 on trying to control the humidity levels in the house. I'd guess your house is getting very dry in the winter, do you have forced air heating with a humidifier installed?
 

labman

Thread starter
Messages
8,711
Location
Nothern USA
No the moisture level in the house is very good in the winter. The humidity gage runs about 60%. The crawl space may be very low. I have thought about shellacing the underside of the floor once it swells in the summer to seal in the moisture.
 
Messages
7,742
Location
MI
The guys above are right that sealants will slow moisture adjustments, but not eliminate it. And, if you "super seal" only one side, it might tend to cup. My guess is that your floor was installed with the wood not fully kiln dried. It was too green and in an "expanded state". You applied it "swollen" and tight. Now every winter it dries down to it's "correct" content and shrinks to show gaps. If it had been installed tight at the correct moisture level (dry), it would expand a bit in the summer (still tight) and in the winter dry down and shrink, but still tight (as originally installed). A neighbor just ripped out his entire hardwood floor for similar reasons.
 
Messages
19,479
Location
Chicago Area
Good luck. A good humidifier will help greatly in the winter, but it only goes in the right direction, and will not stop the whole house form changing from the dryness caused by heating. Even floating floors can do this, when they are properly installed.
 
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