Hardwood flooring installation questions
Hello – I’m about to start installing 3/4″ x 5 1/4″ maple pre-finished hardwood floors in my new house I am building. I have a couple questions, since the tile we selected in a couple rooms which “butt up” to the hardwood is thicker than “normal” tile, I need to skin a sheet of 1/4″ plywood on top the existing subfloor. My first question is what is the quickest but still effective way to instal this. My thoughts would be if I glued it down and screwed it every say 8″ all the way around I should be ok since I still have to put 2″ nails through the hardwood which will also help hold the 1/4″ ply down? Any other suggestions? can I just staple it?
My second question is that the manufacturer requires 40 – 45% relative humidity to be maintained in the house year-end. I live in a very humid climate and from what I know on the topic (which isn’t that much I must admit) is that at this low humidity level, this will ruin my furniture, compromise the drywall joints, etc. Any thoughts? What is the “practical” solution for this since I’m assuming this is “recommended” by all hardwood floor manufacturers, especially 5 1/4″ thick boards.
Just as an FYI – I am going to install the HW when the moisture content of the subfloor is less than 12% and the HW is around 9%.
Thanks in advance for your help!
Replies
You shouldn't have a problem with the plywood sub-floor as long as you leave an 1/8" gap at each sheet. And yes, you can staple it down as long as you make sure that the staples are seated properly...and don't forget to put down some red rosin paper.
As for the humidity. I think that 40 -45% is a little too restrictive on their part. I think the norm is between 35% and 55%.
PS: You can rectify almost any difference in hight of adjoining floors with a termination strip--ie: reducer strip, T-molding, ect.
Lets go back to the tile is it down already? If not what is it going on? If you are planning on a half inches tile board why not a 1/4" instead? You say the tile is thicker then normal, How thick is the tile? Most tile with a 1/4 inch board won't exceed 3/4". Even if the tile is taller by how much? I have found that you can have a tile surface and a wood surface vary by a max of 1/8 inch tops without any problem, you leave the joint between the two a little wider then the standard grout joint you used and fill with a matched sanded caulk sloping the joint.
Standard 1/4 ply is pretty thin and soft and sometimes has voids, it will be hard to get a squeaklesss floor. You would need to go to a void less ply the one made to go under vinyl (expensive). There was an underlayment out that was a 1/4 wafer board that was guaranted not to swell if it got wet, and was voidless HD used to carry it. Have not seen it there in a bit, but a lot cheaper. Install the way the manufactor recommends.
As to humidity you need to measure your inside humidity to see where you are, just because you have 80% out does not mean 80 in.
Wallyo
Edited 2/7/2008 12:42 pm ET by wallyo
Edited 2/7/2008 12:44 pm ET by wallyo
Grandchat27
Ok a few points.. the reason they are so concerned about maintining humidity is wide maple boards like yours will shrink and swell a lot depending on humidity.
If you aircondition/heat your house year around then your household humidity will be much lower than that normally.. and their rules won't hold up.
on the other hand if you go from 7% humidity (winter) to 60 to80% humidity during the summer those boards will open and close up the joints by a dramatic amount..
If you assemble everything now during the winter and the subfloor is already dry when summer rolls around the flooring will cup badly.. Maybe even buckle.
Conversely if the subflooring is still a little green and the flooring is dry next winter you will be staring at ugly gaps between boards..
Don't dispare.. my place has boards as wide as 22 inches and they can be dealt with..
Here's perfect.. subfloor less than 7% moisture flooring less than 7% moisture and humidity never gets over 20% you can bang those boards in just fine.. Personally I'd use pink rosen paper under the flooring but over the plywood (yes a handfull of nails (don't glue) will hold the plywood in place untill the flooring staples hold it permanently. Leave a small gap between sheets)..
Other possible solutions exist so ask if I didn't cover what you expect the actual conditions to be..
Frenchy,
Just to confirm what you are saying so I don't screw this up since I would have to have to rip out the 1,500 ft2 I have to install next year.
I should install the 1/4" subfloor (to match the height of the tile) with a handful of shares until the hardwood nails hold it permantly. If I get the 1/4" subfloor delivered say tomorrow, it will likely need about 1 week to "dry out" also to an acceptable level. The existing subfloors I would imagine should be at an accceptable level since the house has been heated to about 65 degrees for a few weeks now and the house has been waterproof for about 1.5 months now.
A couple questions - does the existing 3/4" advantech subfloor AND the 1/4" add'l subfloor need to be at that "less than 7% moisture content"? Or is it one or the other?
Last thing - if my house is climate controlled I should have no problems with the severe expansion and contraction between the seasons?
I am expecting to have some "gaps" next year as it expands and contracts, I'm more worried about cupping / buckling.
Thanks again for your help.
grandchat27
OH! It's a new subfloor, well that changes the game dramatically.
You see your house is built with basically green wood.. I know it says KD 19 on a lot of the wood used to build it but that simply means it's dried to 19% moisture plus or minus 2% Green wood freshly cut may not be dramatically wetter than that..
Wood to meet it's normal range once dried will need to get down to about 7% moisture and a few months isn't enough to achieve that..
Now comes judgement and experiance.. You see your finished floor may or may not be fully dried down to the 7% required.. Since it's prefinished it's very nearly impossible to tell.. If you have access to a moisture meter you could poke the back side as deep as possible and get an idea.. A better test is slice a chunk of the wood in half well enough away from the end that moisture loss thru the ends won't affect the readings (about a foot or so from an end). The trouble with that method is the very act of cutting the wood dries it due to friction involved in the cutting process. So now you have to poke the prongs as deeply as possible into the grain. That isn't easy in a hard dense wood like maple..
If you stack the wood on your floor to aclimatize it all you will be doing is adding moisture from the green drying wood into possibly dry finished flooring..
OK I need to get even more technical, I hope you are following me thus far.. Don't be discouraged if I'm confusing you.. I'll hang in there in an attempt to clarify everything to your satisfaction so you understand the process and what's involved.. Just please ask.. If you don't understand something (or even anything) just ask about whatever you are confused about.. I like to help..
The technical stuff is the differance between bound water and normal moisture..
Put a dry board outside in the rain and as soon as the rain stops bring it back inside out of the rain and it will quickly dry back to whatever dryness it was before the rain..(exactly how fast depends on things like how dry things are inside and how dry the wood actually was).
However when a tree is cut down there is water in the cell structure of the wood and it's trapped inside by the cell wall.. it won't come out nearly as fast.. in normal conditions dense wood like maple takes one year of drying in normal air conditions for each inch of thickness..
Now that term normal air conditions gets really a lot of abuse.. I've had maple an inch thick take well in excess of three years to dry out to a true 7% moisture. Or I can dry maple inside of about a month if I use the right approach.. (details are far too complex to cover here, ask if you really want to know)
What all that is about is how dry is your flooring? If you ask your dealer they will all tell you that it's been dried to the required 7% Most don't really know! Even some with moisture meters don't really understand how to measure moisture properly..
So here's the gamble. If you put wood that isn't really dry on top of green subflooring the not really dry finished flooring will shrink as it dries.. the subflooring will shrink a lot and you might luck out and avoid cupping if the boards are nailed to gether ever so slightly loose.. (about what a typical do-it-yourselfer will do)
If the finished flooring is really dry (possible with the slow down in housing construction and the probablity that the wood has been around in a store or someplace for a while) and you nail it together too tightly now there is a real possiblity of cupping in the summer..
The ideal time to install finished flooring is mid spring or mid fall.. at those times wood is half way between it's extremes and when it shrinks in the winter won't open up too wide and as it swells from summer moisture it won't expand too much further..
Your whole floor in a perfect world should be at the 7% but thousands of homes have hardwood floors laid over green subfloors without problems.. The difficulty is you aren't nailing on 2 1/4 inch wide boards you are nailing almost 6 inch wide boards.. There is less tolerance for forgiveness the wider the boards are..
There are other solutions.. you could face nail the boards with ornamental nails, you could screw the flooring down using either decorative screws or plugs (very easy to make and near free if you have scrap wood and a drill press).. or you can screw the boards from below if you have access to the floor from underneath.. (very time consuming)
Finally climate controlling your house will afford you with the potential for less problems. However power does sometimes go off and heating/airconditioning units can and do fail.. a few hours or even a day isn't a problem.. longer may or may not be a problem depending on a lot of factors..
Let me caution you.. I'm giving you probably way more information than you need.. It 's sounding pretty complex and I believe that if you ignore me completely you still stand a chance of having a successful floor install. Hopefully reading and understanding will increase your chances of success..
Frenchy,
Thanks for the details - I do appreciate you taking the time to explain things, however I still have some questions. First, I would love to avoid using a 1/4" of ply however I can't just use a transition piece since the transition from HW to tile includes about a 4' "serpentine cut" which obviously complicates everything quite a bit. I can avoid a lot of problems but using angles instead, but aestethically it won't look as nice. I'm very nervous introducing another sheet of ply to the problem. Say if I have the original 3/4" advantech subfloor down for a few months, then I introduce this new 1/4" ply + the HW that's been accimilating for about 1.5 weeks - it seems destined to fail.
First question I guess is should I bother with the work, risk, cost, etc. of adding the extra 1/4" ply just for looks? I know this is a personal choice, but if it's going to cause complexities than I might just avoid it all together.
Second - if I do go with the 1/4" ply - I'm assuming I should be able to get a moisture reader and tell and if it's around 7% then I'm assuming it should be ok? What about the moisture in the subfloor below this? I won't be able to check the moisture after I install the 1/4" on top of that.
Third - how should I store the HW to let it dry out the best in my house to avoid the wood absorbing some of the moisture on the "green" subfloor?
Lastly, I truly hope that if I get a moisture reader and check the HW and subfloor (whether it's the original 3/4" or the added 1/4" ply) and they are both close (I mean within 2 % or so) of the 7% threshold, then I am hoping I should be ok? I was going to leave 1/2" - 3/4" on either side of the walls to allow for additional expansion compared to the tranditional 2 1/4" HW floors.
Any other thoughts, comments, suggestions would be greatly appreciated since I have quite a bit of $$$ invested just in the HW alone, I don't want to have to rip it out later on.
Thanks again for your help, and your detailed responses.
Here is some info and a link to the under layment I was referring to, I don't know if this is the exact one If not it is very similar, this one is a potlatch product.Created specifically for the floor-covering industry, EnStron is a high-density, thin underlayment panel with a smooth, blemish-free face and a fine surface nap that encourages maximum adhesion of various resilient floor coverings. Also available EnStron Plus. EnStron Plus is ideally suited for high humidity and moisture areas. EnStronTM and EnStron Plus are now available with no added Urea Formaldehyde and carry a 15-year limited warranty*.http://www.potlatchcorp.com/EnStron.aspxFrenchy has my head spinning I don't know why your subfloor would be "green", even if the subfloor was at one point wet It would have to be dry at this point, if you are to the stage of being able to install the hardwood your house must of been dried in for several months now. Potlach recommends that their panels acclimatize for up to 48 hours.The point I am try to make is not to use regular plywood use a product that is manufactured as an underlayment. Follow the manufacturers instructions if the underlayment manufacture says acclimatize for 48 hour, acclimatize it for 48 hours. If it says nail with a ringshank nail every 6" on edge and every 8" center with 8" rows do itPrefinished flooring is very stable unfinished not as stable, I am installing a Bamboo floor it is finished on all 6 sides (hardly anywhere for moisture to go in or out) but I let it acclimatize the 5 days they said to. Just do what the manufacture says.In general if you follow a given set of instructions you should have no problem. If one arises then you have the manufactures warranty to fall on, you can say I did it per your instructions why do I have a problem. Believe me it works had an Armstrong Floor go bad, their recommend glue bubbled their perimeter glue vinyl, they eat the materials $500.00.If your are worried about transfer of moisture from subfloor to hard wood use 15# asphalt felt. In the east and mid west rosin paper is the choice it seems in the west we use felt. Lot of arguments on BT about which is right. Either will work I think felt does more to block moisture.In your original post you were worried about the humidity of the house measure it to see if it falls in that range.If you follow the manufactures suggestions you should have no problems. Is the maple from a well known supplier?The reason to acclimatize something is to bring it to the standard of the environment, following Frenchy's advice, if I follow him correctly, you would be bringing the environment to the standard of the HW.Edited 2/8/2008 9:03 am ET by wallyo
Edited 2/8/2008 9:50 am ET by wallyo
wallyo,
You apparently confuse the words green and wet.. allow me to explain.. wood gets wet and then quickly dries back to whatever stage of drying it was at.. that's absolutely true.. however most houses are built with wood that is still relatively green
KD19 is the most common of the kiln dried woods.. KD 19 means the moisture is around 19% plus or minus 2% Wood from the center of a bundle will definately be on the plus side. That is what is properly called bound water since it's bound into the wood cells and retained for far longer than water that simply spashes or gets on wood.
Normal air drying typically reduces that bound water to standard levels by one inch per year, faster inside a heated home but don't forget there are thousands of bd.ft. of wood drying out plus all the moisture from drywalling and painting etc.. That's a lot of moisture to get rid of..
Aged homes have wood moisture down around 7% depending on their location. So the complexities of nailing into a moving target occur.. there isn't as much risk with typical 2 1/4 inch wide flooring but as you move to 5 1/2 inch wide the wood shrinkage and expansion gets a lot bigger..
( you should see the calculations I need for my 22 inch wide boards) <grin>
Frenchy I understand your point between wet and green. The point I am making is if the flooring is to properly climitized to what ever the manufacture says to the house in amount of days, he does not need to even bother with a moisture meter. You are making a simple flooring install into a mission to mars.As to leavIng the flooring in the boxes: Do what the Manufacture says! The manufacture of the 700 sf of Bamboo I am installing says "Take the flooring out of its box and wrapper and let it climatize" In fact every prefinished floor I've installed has said to take it out of its' box. Unfinished 22" boards total different story no doubt, Grandchat27 is not installing 22 inch boards If a 22 were to shrink even 2% it would move .44" where a 5 inch board would move .1" just more gaps. One is almost livable the other is not Most unfinished hard wood is not boxed no need to worry about un wrapping it just stack it so air flows around it.Flooring mishaps do happen but they are extremely rare and you only hear the horror stories, millions of board feet of HW is installed every year without a problem to thousand of very happy customer who don't wait to fall or spring to have there floors put in. Just do what the Manufacture says Grandchat and you will be fine. If you are in doubt as to what 1/4 leveler to you and they don't say call them and ask. I have installed thousands and refinished thousands of square feet of HW flooring as well as other types PERGO LIKE and have never had a problem when installing by the given dirrections and lacking those the standards of the industry. Most prefinished has instructions included.JDRHI clearly spells out what I have been saying:"Do not rely on the flooring nails to penetrate and act to secure both flooring and subflooring."He just put it in to the point and in plain english. Thank you JDRHI. I need to go pound some Bamboo now!Wallyo
Let me throw my 2c in here too. I have a oak (Bruce-Anderson) prefinished 3.25" planks down on about 1/3 of my living room and have 16 boxes open and stacked in my nearby family room getting use to the humidifier (thanks to this group) my original humidity was around 19% now I am running around 30% and holding because it is -10 outside right now.
Anyway I ended up returning 35 boxes to Lowes and have this new flooring acclimating. I made a small template to check my width of the planks, just one board about a foot long with two other boards nailed to the board to provide a crude hand held width gage. My new wood is nearly perfect, from what I have checked it looks to be within +- 1-2mm which I can work with and is within manf. spec. If you make a gage like that and check your boards before you nail them down you will be putting down a fairly tight floor. IF you don't check you could end up like I was with my originally laid floor and constantly fighting varying widths flooring. What a PITA. I had to raise hell with Lowes to get it swapped out. Even if the flooring is unfinished having a helper sort boards in piles of common widths will result in a better looking floor without as much puttying. Granted they will all move but I think that if like sized boards are grouped the gapatosis will be minimunized.
Good luck
Wallyo
I learned about flooring from a old German who wanted his floors to be perfect.. Sure he installed semi green flooring over green fresh subflooring but he calculated the expansion/shrinkage down to the knats butt hair..
I don't know you so I can't say, you may do that intuatively without even thinking.. a little tighter on greener wood a little looser on nice dry wood.. You may atomatically adjust for the wider baords and compensate for maple over Oak over Fir or whatever else.. you may automatically adjust for time of year and humidity.
The OP doesn't sound like he has that sort of experiance.. I'm trying to spell things out which probably took you a long time to acquire not to suggest that you are wrong or my way is best..
I do know that of all the flooring installers I've met over the decades each seems to have their own little twist or way to do things to compensate. According to them everybody else is wrong and a hack..
That is one thing I won't do..
(except all unfinished floors should be shellaced <grin> )
Grandchat27
Glad you could hang in there and follow all of that..
I note someone else is still confused as to the differance between wet and green..
As to the 1/4 ply if you want it, it shouuld be no real problem.. when they slice off the layers of wood that brings the plywood dryer than it would be if it were actually Kiln dried, usually! (depends on when the logs were harvested) So if plywood will match your heights and that's how you want to solve the transistion it shouldn't present a problem..
Frankly you need to store the flooring away from the subfloor. Lay down a bed of say 2x4's and then set some poly over the 2x4's you may as well leave the finished flooring in the box untill you use it because spreading it out will induce moisture rather than dry it out.
New houses have tons of moisture in them. From the green wood, the sheetrock, paint etc.. that doesn't disappear in a month.
There are plenty of relatively inexpensive moisture meters out.. $99 will buy you a good one.. I own a mini Lingo which is a common one. You can buy them on line from Amazon's http://www.toolcribofthenorth.com , or from http://www.sevencornershardware.com
Remember to take your readings as close to the middle as you can.. (and make the temp and species correction) for accuracy. On the other hand a few percent isn't going to totally ruin everything. subflooring wood and finished flooring wood at a similar moisture and mid spring/mid fall is probably the easiest way to get things exactly correct..
As for spacing.. don't worry about lengthwise.. wood doesn't move any significant amount lengthwise simply width wise.. I would go to the long side of the spacing for width don't forget you are putting down 5 1/2 inch boards not the more common 2 1/4 inch boards.
I would add the 1/4" ply and bring all floor levels to the same height.
I personally hate differing floor heights. A little more palatable if the transition occurs at a door where a saddle can be used, but an outright eyesore and trip hazard/annoyance goiing from rooms not seperated by doors.
Fasten the 1/4" plywoood securely. To all joists, not just the edges.
Do not rely on the flooring nails to penetrate and act to secure both flooring and subflooring.
J. D. ReynoldsHome Improvements
If the hardwood and tile are in different rooms, then I would forget the 1/4" underlayment and make hardwood thresholds to create a more attractive transition under the doors or in the openings. Simply bevel the hardwood side to match.
Any house should stay in the 30-40% RH range. Higher than that encourages condensation and mold in the winter in addition to swelling of wood; lower and furniture and flooring will shrink and nasal membranes get dry and more susceptible to disease.
Solar & Super-Insulated Healthy Homes
Thanks - to clarify this will be in the same room (not all 1,500 ft2, just the living room is directly connected to the dining area which has tile).
I totally agree with the transition. This is what I always try to do. Raising an entire floor to meet another floor is just a paradigm. Transitions actually have a beauty of their own.
Here is how I did the bathroom to bedroom I just finished.
So you live in a very humid climate? This would mean that you are probably within a couple hundred miles of the gulf. If so, kiln dry to you is 11% moisture. Thus the desired equilibrium moisture content would be 11%. In that case the wood flooring should be stored in the heated building for 15 to 30 days with the temperature set 5 degrees above the outside temperature.It should be loosened or unboxed and at least a foot above the floor.
I've never heard of a floor cupping from being laid too tight. Cupping comes from dampness from below. Lay the floor as tight as you can and allow 3/8" on each side for expansion and if it is laid at the right moisture content you won't have any problems.
Flooring is usually dried to a suitable moisture content. when used in a larger area such as a gymnasium more thought should be given to expansion. 1/8" would still suffice for the end walls.
A moisture meter is not extremely accurate. Your feel on a freshly cut piece at least a foot from the end will tell you just as much. If you want to know exactly the moisture content then cut a foot section out of the middle of a representative piece and cut that into 5 or 6 pieces and weigh them on a very precise gram scale. [Borrow one from your buddy who loads his own ammo.] Now you must oven dry them until they no longer lose weight. Set the oven at 215 degrees.
Percent moisture content=
Weight when cut - ovendry weight
----------------------------- x 100
ovendry weight
If you can't weigh it immediately then put the pieces in a plastic bag at once. If you live in the 11% area and if your wood is within 2% you won't have a problem. LOL