We are looking at putting new floors in our cottage in Ontario Canada. There is a plywood subfloor already in place. We have been told that engineered hardwood is the way to proceed. My question is as our cottage in not heated in the winter months and the temperature goes down to -20 to -30 .... will the floor expand and contract to the point it will buckle, crack or peel? We don't plan on nailing it down but using a click floating floor made of engineered hardwood. Lumber Liquidators has just opened up in Canada in the last 6 months. we are looking at purchasing the Brazilian Koa flooring. Other websites have said this scratches easily. Any help would be appreciated. Thanks

I have seen wood flooring and engineered flooring in similar spaces here in Minnesota that have had no issues. I also think engineered flooring would not have issues. However, I have never actually installed wood flooring in a place that is not heated during the winter months. Koa is a good option, however, I am not a big fan of LL products.

Sorry to disagree...I've installed a boat load of Koa. If the environmental conditions aren't stable..it will blow up sooner than most.

I second Howard's thoughts, especially after noticing the Koa product...in Canada. Only time will tell in so far as how their exotic hardwoods will do in such cold climates. But then LL is all over the map nowadays, even Montana. Maybe they have a grip on certain issues?

Thanks for your responses ... do you have any engineered hardwood suggestions if Brazilian KOA is not recommended??

We have had quite a few questions concerning unheated cabins lately. The only wood I would put in there is some old reclaimed barn wood and yes it will have big gaps.

I should share my experience because my home is a cabin...for eight months out of the year. Mid November when all the leaves are off the trees I head to Florida until mid March or so. Winters in North Georgia are not as severe as Canada by dipping to the mid teens a half a dozen nights and maybe a few nights near 8 or 10. This place was built with White Pine with the floor being a solid 5" finished natural. I keep some power on for the fridge and a dehumidifier set at 35% Rh when I'm not here.

The floors do contract, but they were never installed tight to begin with. I don't even think they used flooring cleats because I can't see them underneath in the crawl space. A few boards will gap to the point a quarter will fit loosely. When summer rolls around those gaps close to the point a dime won't fit. The only problem if there is one, and I'm not choosey, is the dirt that gets swept into the cracks and stays there. If the floor was darker you would not see it.

So why doesn't this floor blow-up in the summer? I think it has to do with where the product came from...locally. That's my take. It's all about moisture.

Well, most wood manufacturers limits are 60 degrees to 80 degrees with relative humidity 35% t0 55% as an inspector I quite frequently see the results when these limits are not followed. Manufacturers know the limits of their products better than anybody. I started checking nailing schedules and moisture content in floors that my company, Wood Floors By Beto El Paso TX, and discovered nailing schedules far short at times up to nineteen inches apart and not within 1" to 3" of the ends. Typically gaps are expected particularly in our arid southwest. Yes some of these floors have been down 40 to 50 years BUT that was the way they were when they bought them so they want to know what can be done about it?
Oh, did I mention a good many of them have excessive squeakiness.
When one stresses a wood floor excessively what happens? Cleats, nails, glue whatever typically fail! That's what!
So if you want to chance all that no problem. I know a fellow in California that pushes the limit and he says never has a problem BUT he also states that he tests tests tests before doing so to see the result. I am from New Hampshire originally and as I recall wood furniture would fall apart in wintertime, doors you barely open in summer worked great in the winter. Wood is wood and swells and contracts depending on conditions. Charles Peterson, buy his book you will learn a lot I've been at this for 40 years and I definitely have.
Step 1 determine home's average interior temperature Step 2 Determine the home's expected relative humidity level in January when levels are lowest. Step 3 Determine the home's expected relative humidity level in June when levels are highest. Step 4 Acclimate boards to moisture levels in the middle of those values. Typically 70 degrees temp 30% low humidity High humidity 50% = 7.7% moisture content. The table is available from The Wood Handbook US Forestry Dept. if anyone is interested you can download the 497 page book from their website.
Bottom line if installing in summer expect gaps in the winter also don't be surprised if you have movement.

Regarding Brazilian Koa and other exotics that grow in hot, humid, wet climates Mohawk and most manufacturers basically using these woods in areas substantially different from that environment require higher humidity levels upwards to 40% to 60% to perform properly. The one thing constantly drilled into us at the NWFA Inspection school was manufacturers guidelines supersede NWFA or any other organizations guidelines.