Wooden floor became very slick after adding large rug

Q: We recently moved into a home with very nice wooden floors. We added a large oriental rug in the middle of the room. Within a day or so, the wooden floor became very slick. I have vacuumed, cleaned the wooden floor (which helps for a day), but it quickly becomes slick again.

A: Is it possible this carpet is shedding either tiny fibers or some stain repellent and you are tracking it onto the wooden floor? I would purchase a polyurethane cleaner and try using it as needed. Bona Kemi Pacific floor cleaner, Mirage floor cleaner for example, which can be purchased from your local hardwood flooring retailer. Or buy online: http://www.hardwoodcleaner.com
or http://www.circa1850.com
They have a product called Bare Floor.

Planning to close down the house for the winter months

Q: My father has a 30 year-old, nailed down hardwood floor. This winter is the first time he is planning to close down the house for the winter months (drain water pipes and shut down the heat). He is concerned that if he does not leave any heat on in the house that his hardwood floors will be damaged.

The outdoor temperatures can vary from highs of 9 to 12C during the day to lows of -30C at night. The house would be closed between January and April probably. Is my father right to be concerned about his hardwood floors? If yes, what minimum temperature should he keep in the house?

A: I’m not as concerned with the cold temperatures per se as I am with the lack of any exchange of fresh air in the house. I would be worried about possible condensation eventually occurring throughout the house. Perhaps he could leave the heat set for around 40F-50F to keep things above freezing. Draining the pipes is still a good idea just in case something went wrong with the furnace.

It would be interesting to monitor the RH in the house under real world conditions, both when it is very cold inside and when it is above freezing. One thing I am sure of: Unless the house has a lot of windows exposed to direct sunlight, if it gets freezing cold in the house, it will stay freezing cold.

Turning the heat off in winter

Q: We had new oak floors put in 3 years ago. We would like to go away for 3 months in the winter and turn the heat off. What can happen to the floors?

A: Well, it can get damp in the house without fresh air exchange. The sun will pass in the morning and heat up certain rooms and then get cold at night which can cause moisture to condense. You could get some cupping of the wood. Couldn’t you just turn the heat down to 50F and have a neighbour come in every few days or each week just to air the house out a bit?

Here’s a longer answer related to this: What is the lowest wood floor safe temperature that we can have our thermostat set at (when away)?

Protection under the fridge?

Q: I am redoing a kitchen with wood flooring. Should I put some covering under the fridge to protect the floor from any drips, wayward ice cubes or condensation? The fridge will have some space between it and the surrounding cabinet, so I should have room. I hear ice cubes fall somewhere in it now and wonder what I’ll find when we move it from its current spot for the remodel. I just would like to protect the floor as much as is reasonable… thanks!

A: What did you have in mind to place on the floor? I think if the wood is well finished, that should be good enough. Ice makers cause problems often enough. And I don’t mean an errant ice cube now and then. I mean a full on leak. If that happens you will be looking at damage for sure. Whoever hooks it up needs to make sure it is not leaking.

Follow-up Q: I didn’t know if I should place some kind of plastic sheeting under the fridge on top of the flooring..

A: I think the plastic sheeting could actually be counter productive. If there is any moisture coming from below, as wood does tend to allow moisture to pass through it, you would end up with condensation under the sheet. Ample air circulation is a good thing.

Related Q: Is there a protective sheet that can be put over hardwood floor before putting in a built in refrigerator, to protect against water leaks?

A: A protective, water proof sheet to use under your refrigerator? Not that I’ve ever heard of. Tell your plumber to make sure it is connected correctly. I think covering the wood floor with a water proof sheet may cause more harm than good. Wood absorbs and releases moisture so you want it to be able to breath.

Cleaning a polyurethane floor that’s been coated with wax

Q: I moved into a house that has real hardwood floors. I do not know for certain what finish is on it but after testing, it seems to be polyurethane. However, it must have been waxed over at some point because it gets clear streaks/marks when things get dragged across it. I’ve tried a few techniques, but nothing has worked to remove the marks. Also, should I use a cleaner for waxed floors? Thank you!

A: I would try to remove the wax. A product that can help accomplish this is Tie Tac from Poloplaz. You would need a floor polisher with a mildly abrasive pad. Put the cleaner in a spray bottle and mist a section at a time. Buff over the wet spray thoroughly and do this to the entire floor. Then have a towel well dampened in the solution and wrap around a push broom. Go up and down the floor. Let this dry and then with a clean towel wipe it down again.

Similar Q: I recently bought a house with wall to wall hardwood flooring. The floor could use another protective coat to spice it up; however, I believe it has been waxed in the past. My question is, how do I remove the wax and put another coat of urethane on the floor?

A: Are you saying wax has been applied to a polyurethane finish? If so, here are a couple of possibilities. You could clean the floors with any number of polyurethane cleaners on the market. Here is one of them: www.hardwoodcleaner.com.

You might also use a TSP solution. I think I would go over it a couple of times and then buff or abrade the existing finish, clean up well and re-coat.

Using a steamer vac on wood floor

Q: I have finished in place rosewood floors. I’ve been using a steamer vac, spraying a mixture of water, vinegar, and droplet of dawn dish liquid. I’m having an issue with an oily residue! I went over the floors 5 times and it’s almost as if it’s getting worse. Not sure if it’s a residue in the cotton pads? Is it possible for the oil to come out of the rosewood floor? Through the poly?

A: Using a steam cleaner on a hardwood floor is a really really bad idea. You need to stop that and let the floor settle for a while. There are floor cleaners you can buy from wood flooring professionals which won’t destroy your floor. You simply spray a bit on a micro weave or terry cloth mop and wipe your floor. I hope you don’t have to have this floor refinished.

Similar Q: Using a floor steamer seems to have become popular to clean wood floors. We have recently installed hickory wood floors in our house. I am contemplating getting a steamer in order to make the cleaning easier but am concerned about damaging the wood due to the moisture and heat. There isn’t a lot of moisture left on the floor but it does get quite warm. What would you recommend? Thank you for your time.

A: I’m glad you asked first! Absolutely NO to the steamer. I don’t know what type of finish your floor has but I will assume some type of top coat such as polyurethane. Vacuum regularly with a soft brush. There are any number of cleaners available manufactured by wood floor manufacturers and floor finish manufacturers that do a good job of removing stuck on grime. You local wood floor retailer will have something for you or you an check out Poloplaz, Bona Kemi, Basic Coatings or Mirage Floors for a start. Simply spray a small area and wipe with a micro weave or terry cloth mop. Oil soaps are not a great idea and nor are swiffer products as their product data sheet indicates the solution contains wax which will create an adhesion issue if you ever tried to have the floors re-coated.

Hardwood floor in a barn

Q: I’m going to be putting a hardwood (probably oak) floor down in a barn. This barn has gaps and holes in the siding so it’s kind of exposed to the elements. It’s definitely exposed to the temperature. How should I treat the wood? Should I even bother letting it acclimate? Thank you in advance.

A: Quite an upgrade. I’d probably give it a couple of coats of Waterlox penetrating tung oil finish and a couple of coats of Marine varnish. All the best with that. I wouldn’t worry about the acclimation either. Let’s face it: this floor is going to take a beating and isn’t meant to look like a piece of furniture.

Related Q: What do we apply to maple flooring that is being laid on an outside wrap around porch, that is covered by a roof? To seal it up well for Wisconsin weather?

A: I would probably go with a couple of coats of Waterlox followed by a couple of coats of exterior marine varnish. Not the choice of wood I would use on an exterior porch.

Condensation under washer/dryer

Q: What can we use under our clothes dryer on my hickory floor to help with the condensation? We put a plastic tray under the washer, can we use the same under the dryer? Right now I jam a towel a few inches under the dryer & open the windows, but I still get that dang condensation.

A: I wouldn’t have thought you would get any condensation from the two machines. Is the dryer vented outside? I think L.L.Bean has mats for entry ways that don’t allow moisture to pass through.

Follow-up: Thank you. Lot of condensation from the dryer, it is vented outside. I will check will LLBean. I did not want put anything under the dryer just in case it would interrupt air flow.

Oily soap left whitish chalky/ashy haze

Q: We just bought a house that is over 80 yrs. old. There is wood everywhere and we hope to be able to make it look great (we’ve even ripped out almost all the carpet & tack-strips). The banister on the stairs has a lot of black dirt on it, I think no one has used wood polish or anything for decades. I don’t think it has ever been polyurethaned. Not knowing any better, I took some M*****’s Oil Soap and it took away a lot of the black dirt, but now there is a whitish chalky/ashy haze! Oh no! Should I run out and buy some O***** Oil cleaner, will that help? I hope I have not ruined it.

A: You could remove this mess with a polyurethane cleaner or a solution of TSP. Supermarket cleaners are not the way to go.

Follow-up Q: What is TSP, and where can I get it? Should I hire someone to ‘restore’ it? What kind of professional would I look for?

A: TSP is trisodium phosphate and is available at any hardware or big box store. It generally comes in granule form. This sort of work is generally done by a painter.

Related Q: Hi, We have polyurethane finished Brazilian cherry hardwood floors for over 14 years. I have tried many different wood floor cleaners and I now have a oily haze on them. Can we use a floor buffing machine to remove this? I see you recommend Bona cleaner, which I’ve used in the past, but did not get good results. Is there another product you would recommend? The rooms are big, so I need to cover a large area.

A: Yes Poloplaz also makes a floor cleaner as does Basic Coatings. Try to find a wood flooring distributor in your area and contact them. They likely carry somebodies product. Have you been using something like an oil soap?

Protecting wood floors from insecticide treatment

Q: I have bed bugs and everything I read says to seal all cracks in the room before using insecticide. The wood tile floor (Parquet?) has little cracks all round them. It’s very old and unfinished but I just want to seal it, not bothered by color or a bit rough or stains, etc. Ideally a one coat brush/roller job. Do you know of a sealer/treatment that will seal the surface and fill/bridge up to 1/16″ cracks? Many thanks.

A: Any coating you choose, whether it is solvent based, water borne or de-waxed shellac won’t necessarily bridge the gap but will flow into the cracks. There are safe treatments you can use for bug infestations such as Diatomaceous earth / clay. This very fine, talc like powder can be spread about and is harmless to people and pets if ingested. It should not be breathed in though.

Wood flooring maintenance guide

This wood flooring maintenance guide was originally posted on the back of our business card (hence the condensed size), and later on our local business website.

  • Vacuum regularly.
  • Use mats in front of entryways and kitchen sinks.
  • Wipe up liquid spills promptly.
  • Apply felt tack or other floor protectors to the bottoms of chair legs and movable furniture.
  • Weekly cleaning with a polyurethane cleaner: Spray cleaner on cloth and wipe the floor surface.
  • If the finish shows signs of wear, (you can hire a pro to) lightly buff and re-coat with polyurethane.
  • DO NOT: use excessive amounts of water or oil based cleaners on your hardwood floors!
  • DO NOT: apply wax to polyurethane finishes!

Oily paw prints

Q: I read the question about footprints (bare feet) with interest. Our maple floors where finished with the two-part mixed (epoxy?) type of finish. The result is a very low lustre, almost dull finish. Our large dog with big soft warm feet is leaving oily looking marks in the finish that do not leave with cleaning. Nobody but me has cleaned these floors and I have only used hot water/damp mop (for dirt) followed by Bona Hardwood Cleaner. In the sunlight the floors still looked muddled with doggie prints. As no cleaning products are allowed, would an electric buffer with wool pads smooth out these marks?

A: I would have thought the Bona cleaner would removed the oily paw prints. I don’t see what difference a buffer would make, but sometimes anything is worth a try. I would even try a different cleaner. Maybe those offered by Poloplaz, Basic Coatings and others would work better at removing oily marks. Maybe denatured alcohol would remove them?

Similar Q: We recently moved into a home that has wood floors. I seem to get foot print and paw marks (from the dog) on the floors. We have mats in front of the entrances. I have to clean everyday and they’re not coming off. I don’t know much about the floors since the previous owners moved out-of-town. I also get conflicting info… if I should screen and polyurethane the floors or not? The floors are approx. 3 years old. Thanks for your help.

A: I’m assuming the current finish on the floors in a top coat of polyurethane or similar. My best guess is that at some point a product has been used on the finish in an attempt to ‘clean’ them and it has left a residue on the surface. You should give them a good cleaning with a product such as Poloplaz floor cleaner. Depending how severe the contaminants on the surface may be, they also make a stronger cleaner called tie tac.

Related Q: I recently polished my floor, and it was awesome until I noted kitty foot prints. So, I washed it. Now I have a white film with powder residue. What can I do?

A: I have no idea what type of finish is under all this nor what you used when you say you “polished” the floor. If this is a floor with a polyurethane coating then you can purchase a cleaner suited to this from any local wood floor retailer. There are numerous brands which are all basically the same or similar and do a decent job of removing contaminants and not leaving any residue on the finish itself. It seems clear you do have a residue which is why your cat left foot prints.

Light area where dog lays on wood floor

Q: We had our hardwood floors refinished a year ago. We recently got a large puppy who likes to lie at my feet in front of the couch. There is a light area now where he lies. It’s as if the finish has come off. He’s a large terrier. Is oil from his coat doing this?

A: I doubt his just hunkering down at your feet has worn off the finish. It could be oil from his skin. Try cleaning with a polyurethane cleaner or perhaps some denatured alcohol.

Follow-up Q: Thank you for answering my question. Do you recommend any polyurethane cleaner?

A: The polyurethane cleaners are pretty much the same, containing glycol ether. Poloplaz, Basic Coatings, Mirage, and Bona all make their own version one of which you can likely purchase from a local hardwood floor dealer.

Backsplit house/crawl space/humidity issues when considering hardwood

Q: We live in Ontario Canada and have a back split house in which we are thinking seriously about installing hardwood in the living room and dining room. The house was built is the mid 1970’s and it has that amber coloured mahogany trim incl. around door frames. The furniture in the house is french provincial. The only hardwood we could find that compliments the woodwork and furnishings is hickory (the stain the company uses really enhances the wood an brings in the colours in the rooms).

My question is about humidity. We have air conditioning, but only run it when the heat gets absolutely unbearable, because we really enjoy having the windows open in the summer. I’m concerned about humidity affects on the hardwood flooring. Fluctuations range anywhere from 30 to 60. Today it is 63. Should we be considering engineered hardwood or are fluctuations okay? Is hickory a good choice or should we considering another type of wood? Thank you for help!

A: Hickory is a very hard wood. However, it is sensitive to changes in humidity and will experience gapping. A much more stable wood as far as side to side movement is quarter sawn white oak. You can stain it any colour you like to achieve the look you are after.

Follow-up Q: Thank you for your reply. Can you suggest any companies that sell prefinished 1/4 sawn white oak hardwood flooring (some sites are referring to it as tiger). I looked at Mirage and I don’t think they do. Would you suggest engineered as well?

A: Engineered should be very stable due to it’s plywood like construction. The Mirage product is the best engineered I’ve used. Having said that, I’m not a great fan of pre-finished floors for a number of reasons. There is a company in Schomburg called Northern Wide Plank Flooring which mills quarter sawn. Farther north you might look at Stanley Knight Ltd. In Meaford.

Second Follow-up Q: My house is a back split and the crawl space has concrete floor that is 4 1/2 feet high and approximately 20 ft x 20 ft. We store Christmas stuff and luggage under there. It does have a sump pump hole at the far end and it is not insulated. Our living room and dining room sit above this crawl space. I have read that hardwood flooring can’t be laid down over crawl spaces- is this true? Based on information I have provided can I lay hardwood flooring in these rooms? Any information you can provide is much appreciated!

A: The living room is well above the crawl space which has a concrete floor. This space clearly stays dry or you wouldn’t be storing luggage in the space. You should be fine as far as the hardwood floor is concerned. Make sure the wood is acclimated in the room prior to install and check moisture levels between the hardwood and the wood sub floor, which should be within 4% points (the sub floor should not be giving readings more than 4% higher moisture than the hardwood).

Wood floor safe treadmill mats?

Q: We recently had maple engineered wood installed in our home. Can you recommend treadmill mats for hardwood floors? The manufacturer will not give me a straight answer. I am worried about moisture/mold problems, and do not understand what type of rubber to use.

A: Is this a mat to put under the tread mill? Why not just apply felt tacs and certain points on the supporting structure where it sits on the floor?

Follow-up comment: A mat will absorb the shock and protect the floor from dents.

A: I don’t know what to suggest for sure. What about these cheap interlocking sponge mats you can get at Walmart?

Note from Rachel: Here’s a link that mentions “Preserve Your Hardwood Or Carpeted Floor Under Your Treadmill. Pvc Plastic Mat Wont Leave Stains Or Marks. Black With Nonslip Texture.” We don’t have a treadmill to test that out with, though. Interlocking foam mats are also mentioned on other sites re:treadmills on hardwood.

Related Q: Hi, my treadmill rubber supports left block stains on my hardwood floor. They look like they are caused by moisture. What are the solutions for this?

A: If these marks are on the surface, on the finish, you should be able to rub them off with a mildly abrasive pad and some floor cleaner. Even alcohol should work. If it is actually moisture stains in the wood then the spots will have to be sanded or scraped to bare, clean wood. If they are very deep the boards would have to be replaced.

Dirt in the grooves where the boards join

Q: I have an older type hardwood floor. There is dirt in the grooves where the boards join. How can I clean this?

A: You will need to find something narrow enough to go between the boards to loosen the dirt and then use a vacuum with crevice tool attached to suck it out.

Similar Q: There is a lot of dirt embedded in the bevelled edges of our hardwood. What is the best way to clean wood floor grooves?

A: A crevice tool on a vacuum and something to lightly scrape debris loose.

Another Similar Q: have a pre-finished oak floor whose “groves” have turned very dirt looking. We’ve tried lift out the dirt, but it doesn’t help. Can you recommend anything? The floor was beautiful right after it was installed, but this makes it look grimy.

A: Has anyone, in trying to be helpful tried to clean the floor with some super market cleaner which has left a sticky residue on the finish thus attracting and holding daily grime? There are good floor cleaners on the market which can break down and remove such residue. You can find them at any wood flooring distributor and many floor finish and wood floor manufacturers also make such cleaners.

Cover that could be painted/laid onto the hardwood while potty-training the pup

Q: I am looking into getting a new puppy. Our apartment has natural wood floors from the 1800’s (the house was built in 1860). Someone in my office mentioned a silicone cover that could be painted onto the hardwood while we potty-train the pup, and then peeled off later. Does this actually exist and, if so, will it damage the floors?

A: It is possible such a product exists, though I haven’t heard of it. In any case, applying silicone to a wooden floor would be a very bad idea. Even if you could get it off later, if it left any residue at all you would not be able to apply a maintenance coat of finish. The silicone would repel the finish and prevent adhesion.

There’s a company called Paisley Protectives who carry a number of films you can roll onto the floor.

What is the minimum temperature wood floors are safe at, that we can have our thermostat set at (when away)?

Q: We have a home in NC that we do not live in during the winter months. There are hardwood floors throughout the home. We do not want to pay high heating bills since the house is empty, but we also do not want to compromise the floors. What is the lowest safe temperature that we can have our thermostat set at / minimum temperature wood floors can take?

A: This is a difficult question, and one I have not yet come to terms with completely. I don’t think temperature is the main issue. I don’t think cold temperatures by themselves will damage your floor. I took a gamble when I lived in Toronto by installing quarter sawn white oak in an uninsulated but closed veranda. It was all windows with a dirt crawl space below. I left a small heater running to keep the temps above freezing. At night it likely dropped to mid to low 40’s. In the day, with the sun shining temps could go to the mid 70’s even on bitter cold days. However, the space did get an air exchange from coming and going through the door to the outside. Here is an explanation of vacant house syndrome.

CAUSE:
Security -conscious vacationers, a homebuilder’s unsold inventory, whenever a wood floor is deprived of an air flow in the environment, it can and will misbehave. Sunlight through windows generates heat, lowers humidity, moisture vapor enters to balance, nights cool off, humidity builds and wood floors cup. Thermostats set at 60 degrees and outside, winter howls, heating system runs constantly with no moisture added, and floors shrink.

CURE:
Avoid problems by leaving windows “ajar”, have neighbor air the house out occasionally. Treat floors as discussed under cupped, tented, or shrinkage cracks and only after environment returns to normal. Owner to pay.

The above commonly ask questions will help you and your wood floor contractor resolve some of the everyday concerns about wood floors. By no means is this a sure method or procedure. If in doubt, get a second opinion…

Lets just say you have a 5 gallon pail of humidity (moisture). In a cold house that bucket represents a higher level because cold air cannot hold moisture that well, so it will tend to condense on surfaces. Warmer air can hold a lot more moisture in suspension so this doesn’t happen. What are the sources of moisture inside your house? How well is the house insulated and sealed so outside moisture doesn’t get inside? How much sun exposure is there? Best I can say is keep the heat no colder than 50. what about leaving a dehumidifier running? You can have it run directly into a drain.

Follow-up Q: Thank you so much for your reply. We currently have the thermostat set at 65 degrees and we are being told that it is cold there right now with high temperatures in the 20’s. We have never lived in the home since we bought it last year with the hopes of renting it, which has not worked out. We will finally be moving there this July. So, I don’t know definite answers to some of your questions. I think the house is insulated fairly well. And, I think that it does get some sunlight during the day. I’m not sure what you mean by the sources of moisture in the home. We do have a dehumidifier in the basement that runs directly into a drain, but, I think it mainly runs during the summer months. I’m not sure how we would have the dehumidifier drain on the main floor, though.

Anyway, I’m still very confused, so any further input you can pass along would be greatly appreciated. I’m not understanding if it is better to have it warmer or cooler for the humidity levels associated with the floors. The floors are beautiful and one of the reasons we purchased the home and we would hate to have problems surface with them before we even move in. Thank you again for your time and expertise.

A: Sources of moisture? Well, for example a toilet! That is a source of moisture. As soon as people start living in a house, sources of moisture increase. We exhale moisture. We use the sink. We cook. I think I would empty the toilet for sure and shut off the water supply. I’m still consulting a few others on this. I don’t want to give you bad advice and it is a tricky question. Eliminate the possibility for condensation to form on windows, walls etc. and I don’t care how cold it is in the house. If it is as cold inside as outside and there is very low RH in the house, you should be fine with no issues other than perhaps some shrinkage in the wood. Of course, if it is below freezing, you couldn’t run the dehumidifier.

Here is something I noticed the other night. I have hot water rads and vertical blinds which were shut the other night across the front window. It is cold outside. I happened to pull on of the slats back to look outside and noticed water running down the window. Why? I decided to open the blinds part way to allow air movement and the moisture dissipated. Moisture laden air was trapped between the blinds and the cold window so I got condensation. Opening the blinds corrected the issue. Ventilation. Having nobody living in the house should greatly reduce the amount of moisture in the air. The lower the moisture the less condensing on other surfaces. Ventilation and dehumidification I think are more important issue than how cold it is in the house.

I will be back as soon as I have more information.

Follow-up Q: Thank you Craig for helping to educate us regarding this issue. As I mentioned previously, we are concerned about the house being vacant for so long and just don’t want problems with the beautiful wood flooring throughout. You are being so helpful and we will look forward to any other information you can pass along. I think I’m understanding now that it is best to have as low humidity as possible in the house from what you are saying.

A: I’m a member of a flooring forum, so I presented your issue and concerns there. Here is one comment I received:

Facelift-

I recently did an inspection on a home in Eugene, OR. The flooring contractor had done his due diligence and the 4″ BC was not installed before it had acclimated to the home and the dry subfloor. The $1.4 mil home was completed in July ’07 but was not sold and occupied until Aug ’08. during that 14 month period the builder, trying to economize, cut power to the heat source.

Within 60 days of occupation and consistent heating the floor, which looked “pretty nice” at the time of sale, began to shrink and cracks began to open. When I inspected the floor one year after occupation, in spite of the extensive shrinkage and gapping, the average board still measured .015″ wider than the original milled size.

My investigation showed that, during the year of vacancy and no heat, the average outside temp was 54.9 degrees and the average outside rh was 82 %. For the sake of argument, I figured conservatively that if the indoor temp for that period averaged 60 degrees and the rh only 65% each board (with an expansion co-efficient of .00300 for BC) could have expanded 3/64″.

The thing we are talking about is CLIMATE CONTROL. A consistent source of heat will counter-act the chaotic effect of winter sun coming through the window a few hours one or two days a week.

NWFA says that a controlled 30-50% rh and 60-80 F temp will allow for optimum dimensional stability.

A problem with the vacant house syndrome is not only the cold and damp but the unregulated temp swings and shock treatment of the wood that come with periodic bursts of sunshine through the windows. Unofficially, I kept my Willamette Valley (read moist) warehouse 2-4 degrees warmer than the outside temp and never had a problem with any wood I stored there.

I guess the question for your concerned party is how much are they willing to spend to protect their investment.

Does that help to clarify? NWFA feels the temps should not be lower than 60 with RH kept between 30 (which seems rather low to me) and 50% (which seems high to me for winter heating season). I think in winter we should try to keep the RH between 35-42% at about 72F.

Follow-up Q: Thank you so much for all of this information! We currently have the heat temperature set at 62 degrees. So, I’m assuming from what I just read here that we are within a “safe” range. I really don’t know what to do as far as figuring the humidity level.

A: You can buy a hygrometer from Radio Shack etc. or Sears for about $35 which gives you the temperature and RH. Just set it on the floor for half an hour and see what the conditions in the room are. This is a sticky issue for sure. I think I mentioned I installed quarter sawn white oak plank in an enclosed, non insulated porch but left a tiny heater running all winter, just to keep in in the 40’s F range. It would get into the 70’s on the coldest day with the morning sun. So, I had swings in temperature and never had an issue with the floor, but that cut of oak is more stable than flat cut. I think you are fine at the temperature setting you have.

Related Q: We have factory finished hardwood floors. If we leave the house for four months in the winter, what temperature should we set the thermostat on to protect the floors and wood cabinets?

A: I wouldn’t drop the temperature below 65F, and in winter try to maintain a RH level between 35-40%. I would have someone come in once a week to check that everything is OK and let some fresh air in.

Humidity and wood floors

Q: I recently moved into a newly built log home in Northeast Ohio. I have hickory floors. The floors were put down in the dead of winter (January) and the humidity in my house was very low. By May I was having a problem with the floor, wavy in some areas and actually buckling in one room. For the last two weeks I have been running dehumidifiers, ceiling fans, and the air conditioner to try and bring the humidity down, but it almost seems like the waviness is getting worse not better. I understand that the humidity should stay as constant as possible, summer and winter, but what is the ideal humidity for wood floors? The man who installed my floor is telling me 30%, but it seems like I can’t get it there. Any clues on what I could do?

A: I have to assume that this cabin is heated in winter. Humidity is a tricky question and the figures that some companies recommend seem unrealistic outside a laboratory. For example, I have read to keep the RH in the home between 45-50% year round. We could not allow that in our climate! In the winter, we would have streams of water running down the windows and walls. I heat with forced air and in winter it is typically RH 33-40 in my house. I don’t want it dropping any lower or going any higher. I think your installers number of RH 30 is unrealistic for our climate, especially in summer. You couldn’t keep it that low.

I think this is the best work around. When installing in winter with heating in place and typically low RH in the home, a humidifier should be running at that time of year to raise the RH to at least 40%. Like I said, you can’t go much higher without creating condensation issues. But, at least you won’t be under 30% and then face a huge swing when spring comes. If a humidifier had raised the RH in winter when the floor was installed, then you should be able to keep it down to 50-55% in summer. I have one of these digital dehumidifier’s running in my basement and I can set it to any figure I like. It can handle 3000 sq. ft. and does a good job. So, if the floor was installed at about 40% RH in winter and now in summer it rises to 50-55, that is only 10-15% difference and shouldn’t cause a problem.

Here is another factor that can come into play when installing at low RH in winter: You take the wood into the house and let it acclimate. It is dry in the home so the wood shrinks a bit. The wider the board, the greater the expansion and contraction. The floor is installed and nailed nice and tight. You have to know that in summer when the RH increases 30-40% or more, the floor is going to expand. It is absolutely imperative that an expansion gap be left around the perimeter to facilitate the expansion. If the floor is installed tight to the walls in winter, when it expands, something has to give. I would check the floor along the walls. If it is tight, you may have to remove that row of boards or find a way to cut it back to allow an expansion space.

I hope some of this is helpful. Hopefully this floor can be gotten under control and it will settle back down without any repercussions.