My basement project is FINALLY coming to conclusion, and the contractor is planning to bring over the wood today for the floor. It’s engineered hardwood, which will theoretically match the older engineer hardwood in the part that was finished years ago. It will be a floating floor.
The wood is supposed to acclimatize. My problem is that the humidity in the basement varies quite a bit. The old part sometimes bows up quite a lot in the summer. Like, the door scrapes the risen wood. That’s not a problem if I’m good about using the dehumidifier. And maybe it will be less of a problem going forward, as I’ve installed a heat pump, so perhaps that will help keep the humidity down in the summer?
Anyway, I mostly do try to keep the humidity lower. But I am not always consistent. It’s damp now. If I turn off the dehumidifier, the basement will be damp.
Should I “acclimatize” the wood to damp or dry? Bowing seems like a more serious problem than pulling apart. But I’ve never had “pulling apart”, so maybe I’m wrong.
We have a dehumidifier in our basement which is on the ‘auto’ setting. I have it set at the maximum setting, so it runs virtually all the time in the summer, but runs very little in the colder months. I also have a hose running from the machine to our floor drain, so the bucket doesn’t need to be monitored.
But if you don’t have a floor drain, or an alternative method for pumping the water out, then I can see that it would be an issue. And, sorry, I certainly don’t have an answer for acclimatizing the flooring.
Well, that is a less-than-ideal situation for wood flooring, even engineered. You pretty much need to acclimatize it to the damp conditions, However, some engineered flooring has a very small tongue and groove. It’s too late now, but that would be an excellent scenario for the new-ish ceramic wood flooring. Not as warm to the foot, but quite nice.
You may have humidity swings that exceed the manufacturer’s tolerance for the product. That would almost surely void your warranty if you have a problem.
Do you have any idea of what your minimum and maximum RH in the basement actually are?
The passive solution would be flooring that doesn’t care. The active solution will put a lot of burden on you to ensure that you’re keeping the humidity within the acceptable range.
But knowing the manufacturer’s spec and your actual seasonal conditions is probably key.
I run the dehumidifier 24/7/365 in our basement, but I prefer to dump the bucket manually, as we use the water for watering plants (our well water is softened and the bit of extra salt is not ideal).
In the summer I dump the bucket 2-3 times a day. In the winter maybe once every 48 hours…
Our basement flooring is all concrete with an epoxy finish. wooden flooring would scare the heck out of me.
The flooring is likely very dry so your basement will likely be humid enough for the wood to acclimatize even with the dehumidifier running.
The problem will be keeping the humidity under control afterwards. My problem with basement moisture is a result of A/C in the summer. The basement creates a cold air trap and humidity condenses on the cold floor. Over the summer I frequently open the bulk heads and run fans to circulate the air, and I think air circulation may be all I need in the end.
So you have a heat pump. Is that a heat and A/C system, and do you have outlets in the basement? My split system A/Cs are pretty good at reducing humidity but the issues in the basement will remain and I’ll be looking into better fresh air circulation down there.
Yes, but i use the space for square dancing, and ceramic is horrible on your joints. The wood has extra padding underneath, and is really nice.
Despite the occasional bowing, I’ve been very happy with the engineered wood in the previously-finished half of the basement. Which has been there about 20 years, now. I’m just looking for how to optimize the new half.
I put ceramic in the utility room and the storage room, because that’s obviously a good flooring for the situation.
True enough. I guess measuring the moisture content of the old flooring and matching the new would be the ideal. I could loan you a moisture meter if you have time for me to mail it to you.
Hygrometers measure humidity. Hydrometers measure the relative density of a liquid, usually by measuring the buoyancy a solid in the liquid.
For the flooring you need a moisture meter. However, many of them can’t measure the moisture content of kiln dried wood with any accuracy because it so low.
Sorry, I’m sure i have the name wrong. I bought an electronic gadget that claims to report the temperature and relative humidity of the air it is sitting in.
A good flooring installer should have the appropriate kind of moisture meter.
It looks like engineered flooring should be allowed to ‘equilibrate’ to an MC (moisture content) of 6-12%, and its environment should be maintained at between 30-50% RH and 60-80*F temperature.
ETA: Sorry. I posted that too quickly. That figure seems to represent the moisture content of the engineered hardwood flooring as it leaves the factory.
The simple answer, then – as a recovering woodworker – is that you’d want to acclimate the flooring to the average environment that it will experience.
If you shoot for near minimum (ie, driest) RH conditions, then seasonal increases in humidity will ‘swell’ and ‘expand’ the wood.
If you shoot for near maximum (ie, most humid) RH conditions, then seasonal ‘decreases’ in humidity will ‘shrink’ the wood.
If you can ball-park your seasonal average, and hold the wood in that average humidity until it reaches Equilibrium Moisture Content, you’ll probably get as close as you can to a year-round good number, which – depending on the conditions you pick – may match the wood as it comes to you.
What’s my year-round average, with real-world conditions (ie, using or not using HVAC and/or humidification/dehumidification).
Where am I now relative to the year-round average – higher or lower RH?
If I’m either far above or below my average year-round RH, what move could I make to shift things toward that mean?
So … if the answer to those rough questions is that turning OFF your dehumidifier would quite likely shift you toward your year-round mean RH, then … yeah … sounds like a plan.
But I don’t know those numbers in your basement. There are a lot of variables at play here.
If you can use your thermometer/hygrometer and play with it, you’ll get a pretty good idea of today’s #'s with and without your dehumidifier, but it won’t tell you much about your annualized mean.
You really just don’t want to acclimate the flooring at anything approaching your annualized peak (high or low) relative humidity. That’s where you can run into trouble.
One more thing: the same qualified flooring installer that should have a decent moisture meter should also have a better guess than you (or I) might about the average in your basement given your HVAC system and other relevant variables.
He or she should be able to guide you as to the best conditions for acclimating the flooring – what, if anything, to do with the operation of your HVAC or dehumidifier to give you the best long-term result.
Absent any ability to get a more precise recommendation from the installer, … that. I’d also do that
Your ability to do that, though, will – unfortunately – depend on the variables I pointed to:
if you’re exiting your dryer season and the RH in your basement will be rising, then your new flooring will move away from the moisture content of your existing flooring, toward higher moisture content;
if, OTOH, you’re exiting your higher humidity season and your basement humidity will be coming down, then your new flooring will move away from the moisture content of your existing flooring, toward lower moisture content
As your existing flooring does the same thing.
None of this matters if you don’t have wide RH swings, but it sounds like you either can or do. The greater the amplitude of those swings, the more important it will be to shoot for the annualized middle.
I don’t think this is being overanalytical, incidentally. If you ask any woodworker who’s built fine furniture only to have it live in an environment with vastly different conditions than his/her shop, things can go very badly, very quickly.
Oh yes. I collect wooden puzzles. I have a packing puzzle that i determined was impossible. Because it had been made in a very dry climate, and was impossible after it expanded in my climate. I only learned why i hadn’t been able to find a solution after taking with the maker, and learning that I’d ruled out the intended solution. I have a secret box that can only be opened in the summer. It was made in a damp workshop in London, and in the winter it’s much too tight to work. And there are a number of fragile puzzles i chose not to buy because my humidity swings were liable to break them.
They want to start this week, and the stuff only just arrived. Honestly, is not going to acclimatize in that time. I’m betting it’s currently drier than my average. I also think that the failure of “it gets to wet” is worse than the failure of “it gets too dry”. Bowing vs. gapping.
I’m wondering if i should push back on “installation starts later this week.”
There’s an old woodworkers story that your joinery will be tight on just two days of the year. The same month and day you built it and exactly six months later because those are the two days of the year with the same humidity level as the day you made it. It’s not meant to be taken literally, it’s a reminder that the conditions will change through the year. So my suggestion is to use an installer who understands that and has actual experience to know exactly how tight or loose to assemble the flooring for these conditions.
I certainly would. Expansion w/bowing on a dance floor pretty much makes it unusable. To quickly acclimate the wood needs to be unboxed and spread out, ideally so all sides are exposed to air or the concrete. One thing you might consider is using a thicker baseboard or a base shoe and leave a LOT of room for expansion. If the flooring guys know how to install a floor that really floats, leaving an inch or so on all sides of the room would really help.
