Question: I would like to put a raised floor in my dinning room, only the height of a 2×4. The problem is it’s a concrete slab. I’m not sure what to put under the treated 2×4’s to get started. I would appreciate any information you can give me. Thank You Answer: Dear Len Read my article on how and what wood floors are best installed on concrete, it should say it all. This article is available in the search box at the top of this web page and it is entitled INSTALLING HARDWOOD FLOORS ON CONCRETE SLABS.

Question: We are building a new home and wish to use radiant floor heating system (not electric) throughout instead of forced air. We also want hardwood floors…is this possible or must we stick to ceramic/stone floors? Thanks, Neil and Andrea Answer: Dear Neil and Andrea You can have your hardwood floor, but you will have to give them some special care to keep them from moving too much seasonally. Choose the simple hydronic system that places the heating pipes between the joists under the floor, so if any leak occurs the wood floor will not be affected too much. Install at least 1″ or thicker plywood to the joists, with urethane glue and 3″ nails every 6-8″. Install the hardwood first. If you live in a really dry or very damp climate consider applying at least one coat of oil modified polyurethane on the underside of all the boards, and allow a week for this to dry and boards to acclimatize. This combined with the top coat, slows the moisture migration into (during humid summers) and out of (during the dry heating season) of the wood. The best furniture is always well finished on the underside also, for this very reason. Consider using a 3/4″ quarter sawn red oak, or white oak in no more than 2 1/4″ width. NAILED every 6 ” with the proper floor cleats (read my article about this available in the search box at the top of this web page; the Primatec 210). Keep the hot water in the heating system to no more than 80F, be sure of this. Raise the heat slowly in the fall, and heat consistently all winter, even when you are away. Then in the spring let down the heat gradually. In summer the house should be air conditioned, or at least dehumidify the basement. Try to keep the indoor relative humidity to about 40-60% ALL year round. Get a real wet-dry bulb hygrometer to measure this, the little metal ones that come with a thermometer are not accurate. You can get a good one at www.esci.com. Try sku# 848N635. Sounds like too much trouble, you bet. And the ceramic tile will hold the heat better, because of its thermal mass. So my choice would hardwood with a conventional system, or ceramic with the hydronics.

Question: Thanks a million Doc, I have tried to get this info from every source I could think of with no luck. I have seen these floors in magazines but none of the locals have done one in herringbone. I plan on nailing the 3/4″X 21/4″ thick strips to 3/4″ plywood with black paper in between. Wish me luck! Dennis Answer: Dear Dennis The method I described is for GLUE down only. If your are going to nail down the boards, you will have to move the center point to just one diagonal laid strip distant from the shortest wall. It will only be center to the two long walls. I don’t recommend this nail down method as nailing the first few strips may move them out of place. Consider gluing these first few rows down and letting it dry overnight. Or at least face nail some sacrificial pieces so that the following rows won’t shift. Make sure you use flooring nails (not staples), read my article about this available in the search box at the top of this web page. And for nailing close to the wall use 2″ spiral finishing nails and a nail spinner to install the boards split free. Go to http://www.leevalley.com and order this nifty and inexpensive prod # 99K20.01. Oh, and forget the black paper it provides no moisture or squeak resistance. And you won’t be able to keep the chalk lines straight. If you have a damp crawl space under this floor add another 1/4″ plywood so that the 2″ flooring NAILS will not penetrate the two layers, hence a water proof barrier made by the water proof plywood.

Question: Joe I tested bleaching on a hardwood panel and it turned out all white on top. On this white surface, it’s imposibble to apply stains of different colors because the top is white? An i right? thanks Harry Chang Answer: Dear Harry Call me Joseph, if you could please. It is possible to stain a wood that has already been bleached, but I don’t use wood bleach to make a white floor. Joseph If you found this information helpful, please explore the Wood Floor Doctor.com by visiting the rest of our website. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: We are having trouble with the HP we bought from carpet mills of america. Their inspector tells us that we have a moisture level of 5.? in our foundation. The planks are coming unglued and the edges on several planks are scalloping. No one ever tested our floor before it was installed to tell us we had moisture in our foundation. When it was installed the installers had to level the floor in several places and within a few hours were installing the planks right on top of it. Others we talked to that had wood floors installed could not even walk on the leveled floor for 24 hours or more. We have $11,000.00 of wood flooring in our home and we are very sick about it. Please let us know what we can do to get our on professional inspection and what if any thing we can do. Sincerely, Steve and Kathy Davis Answer: Dear Steve and Kathy I’m so sorry to hear of your troubles. But this is a fairly easy one. The 5 the inspector came up with should be 5 on the Tramex Concrete Moisture Encounter meter. It’s a small hand held meter that has probes that are is pressed to the concrete floor. The highest reading allowed for wood is 4 1/2. And if a reading over 4 is detected many more readings should be done, in the wettest season you have. Oh, of course that needs to be done BEFORE they even consider selling you any type of wood floor. Along with this test they could have done a Calcium Chloride moisture emissions test. This test is a little more tricky, but basically it involves taping down a bubble container to the floor with a sample of pre-measured Calcium Chloride in the bubble. After a certain length of time this sample is sent back to the testing company, and they send back the results. A 4 in this case is the maximum pounds per 1000 square feet over 24 hours, allowed for wood floor installation. This is a better So you see in either case you have exceeded the maximum, and hence the bad result. The solution is clear, remove all the hardwood ( you didn’t say of this was solid wood or engineered) clean up the subfloor. And install carpet. You can never have a hardwood floor in that present situation. Don’t be too alarmed by the high readings, all concrete floor emit some moisture, it’s just too high for wood and all vinyl products. Now if you are going to ask me, who is to blame. Well, after 3 court cases, (the last one is described in the Wrong Way Floor in the Case in Point section) I would believe that it is up to the flooring contractor to determine what wood floor, and what method of installation is best in your situation. It is always up to the expert to do all tests, and if they did not they will be responsible for returning to the point at which this all began. Plus maybe punitive damages, and costs of the inconvenience of the first job. And the cost of moving out while they remove and CLEAN the concrete, install new carpet, and you restore your life. Please don’t be sick, just get this sorted, I’m sure a large (at least they sound large) company is not will to risk bad publicity even on a job this size. I just completed a long article on this very subject, wood floors on concrete, and you will see it in the site in the next month or two. It deals with all these problems, moisture, leveling, and picking the right installation method.

Question: We are having trouble with the heritage plank floor we bought from carpet mills of america. Their inspector tells us that we have a moisture level of 5.? in our foundation. The planks are coming unglued and the edges on several planks are scalloping. No one ever tested our floor before it was installed to tell us we had moisture in our foundation. When it was installed the installers had to level the floor in several places and within a few hours were installing the planks right on top of it. Others we talked to that had wood floors installed could not even walk on the leveled floor for 24 hours or more. We have $11,000.00 of wood flooring in our home and we are very sick about it. Please let us know what we can do to get our on professional inspection and what if any thing we can do. Sincerely, Steve and Kathy Davis Answer: Dear Steve and Kathy I’m so sorry to hear of your troubles. But this is a fairly easy one. The 5 the inspector came up with should be 5 on the Tramex Concrete Moisture Encounter meter. It’s a small hand held meter that has probes that are is pressed to the concrete floor. The highest reading allowed for wood is 4 1/2. And if a reading over 4 is detected many more readings should be done, in the wettest season you have. Oh, of course that needs to be done BEFORE they even consider selling you any type of wood floor. Along with this test they could have done a Calcium Chloride moisture emissions test. This test is a little more tricky, but basically it involves taping down a bubble container to the floor with a sample of pre-measured Calcium Chloride in the bubble. After a certain length of time this sample is sent back to the testing company, and they send back the results. A 4 in this case is the maximum pounds per 1000 square feet over 24 hours, allowed for wood floor installation. This is a better So you see in either case you have exceeded the maximum, and hence the bad result. The solution is clear, remove all the hardwood ( you didn’t say of this was solid wood or engineered) clean up the subfloor. And install carpet. You can never have a hardwood floor in that present situation. Don’t be too alarmed by the high readings, all concrete floor emit some moisture, it’s just too high for wood and all vinyl products. Now if you are going to ask me, who is to blame. Well, after 3 court cases, (the last one is described in the Wrong Way Floor in the Case in Point section) I would believe that it is up to the flooring contractor to determine what wood floor, and what method of installation is best in your situation. It is always up to the expert to do all tests, and if they did not they will be responsible for returning to the point at which this all began. Plus maybe punitive damages, and costs of the inconvenience of the first job. And the cost of moving out while they remove and CLEAN the concrete, install new carpet, and you restore your life. Please don’t be sick, just get this sorted, I’m sure a large (at least they sound large) company is not will to risk bad publicity even on a job this size. I just completed a long article on this very subject, wood floors on concrete, and you will see it in the site in the next month or two. It deals with all these problems, moisture, leveling, and picking the right installation method.

Question: I recently bought a 100 year old house with original pine flooring. The contractor refinished them improperly (or with too few coats) because the finish became scratched in just a few weeks and after 6 months it looks like the finish is many years old. Can I recoat it without having to sand it? I’m afraid the floor will not be able to handle any further sanding. Greg Answer: Dear Greg Yes, you can and should recoat it. A pine floor should have at least 4 coats of an oil modified polyurethane. If you only have two, apply two more. You will have to rent a floor buffing machine, and buy a white pad and a 80 grit screen. Screen the floor until it is full of small scratches. Do the edges by hand. Run the buffer in both directions so that all the floor is thoroughly scuffed. Vacuum really well, then wash the floor twice with odorless mineral spirits, so no dust is left. Do it in a sweeping motion so as to draw the fine dust in the direction of exit. Let the solvent dry. Then BRUSH on a heavy coat of poly. Don’t use a lamb’s wood applicator it will cause bubbles. Let that coat dry for at least 2 days, or until when screened, it powders and scratches as before. Let it dry for 48 hours, and be aware that this finish will take 30 days to cure. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: A wood flooring person came in (we had some small water damage) and said the coating on our floors is illegal to use in California. He said he could tell once they started sanding the floor because their eyes started burning and it had a strong odor . . . . – we have lived here a year. I think he said the name of the coating started with a “c”. He suggested we get all of our hardwood floors sanded and put a new coat (finish?) on them, as this toxic coating could affect us as years go by. Do you know anything about this? Answer: Dear Flo Yes, I’m sure some floor finishes are not allowed in California. I hear they outlawed lacquer finishes some years ago, and by now there will be some of the Moisture Cured Polyurethane, or the Swedish Acid cured finished (Glitsa or Syteko) that will also gladly have been knocked off the California paint regulations list. But in all cases the dried film is SAFE. I have personally sanded off all the known floor finishes, industrial and otherwise, and have never experienced any symptoms as described. This is because the dried cured film has no solvents in it (of course) and in most cases is either a nitrocellulose solid or an modified oil solid. Very benign. That all said, you need not worry or do anything. Unless you are personally suffering an eye or throat irritation, the floor finish is fine the way it is. The most toxic floor finish called Glitsa only gases off small amounts of formaldehyde for 3-6 months after it has been applied. And now your finish is older than that, you say it was applied over a year ago, there is still no problem. The toxicity of these finishes is during their application, and why they are banned in some states is that the solvents contribute to air pollution. If you can find the brand name of the finish that was used on the floor originally (not the patch job) I can do the research on it, and get back to you right away. Otherwise, if you have had no ill health effects, you will have no problem with the dry, cured film of any floor finish. Oh, it has been proven the the formaldehyde in the floor finish I mentioned diminishes after 6 months, and this has been tested and documented. So any problems will not get worse like these guys said, but only, invariably better. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: My oak wood floor has been installed for 8 months. Now I have a crack in 50% of the joints. Some wider that the width of a quater, many will hold a dime. What is the industry standard for acceptable cracking? Gary Answer: Dear Gary Here we go again the amazing winter shrinking floors. This is especially a problem with prefinished floors, and if the floor was stapled down on OSB as the subfloor, there will be all kinds of shifting. But wait. Have you been doing your part in stabilizing the environment this solid wood is in ? You should maintain an indoor humidity level of about 40-60%. And I mean all year round. So, if this was a particularly hot and humid summer (a long one at that) where you live, you may have been tempted to throw the doors and windows open, rather than waste energy using the air conditioner. Prefinished floor are not finished on site, so they are susceptible to these high humid conditions, and will swell up quite a bit. The boards will push against each other, and move into the expansion gaps at the long edges. You will not notice this. The indoor humidity can easily reach 80% for weeks if not months. But at some point in the Fall we turn the heat on and bake these floors to desert dryness. An un-humidified house can easily reach a 25% level in the middle of winter. These extremes on solid wood will cause the wood to reach an equilibrium moisture content of as high as 14% in the summer and as little as 5% in the dead of winter. And this movement will easily cause the gaps you speak of and worse. The immediate goal is for you to bring your indoor humidity up to at least 35-40% right now. If you are uncertain of your indoor humidity get a wet-dry bulb thermometer at http://www.e-sci.com/genSci/9/1044/1099/9955.html. This is the proper instrument to measure indoor humidity. The cheap metal ones are not at all accurate, and may mislead you. You can use a furnace powered humidifier, or the portable ones. And in the summer be sure to de-humidify your basement, constantly. and when the indoor humidity level reach past 60 % use the air conditioner. Do all this if you expect your solid wood floors to stay tight. The gaps that you have now are may not be permanent. Don’t put any filler into prefinished floors, it never looks good. In any case wait until spring before you do any filling, and do it sparingly. Don’t even think about repairs until the spring, the floors amy have corrected themselves by then, if you have been diligent in raising your indoor humidity. This sort of thing almost never happens to my site finished floors, the wood is so well sealed that the humidity changes affects it very little. A thick plywood subfloor helps also, and floor nails must be used, never staples. I bet you were never informed of any of this when you bought this floor. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Joseph, Just bought three articles off you on sanding, staining and finishing. I’ve got my very first , never done it before job, in my new apartment me and the mrs have just bought. It an old place in Paris from the 1900’s , I assume its parquet is OAK luckily it’s very simple straight floorboards, no 3D stuff. The tough one is will be explaining to the hardware guy all the terminology in French which you have written in your articles… this brings me to my question. (loved your articles by the way, very professional, and even if the french guy says one thing, i’m sticking to your article and that’s that) I found that in your articles there were many floor mecanic terms which I found hard to comprehend. is it possible you could write a short document or glossary on some of the terms you use. like..feathered edge, anti-vibration pulley belts, cinches, chatter marks, long sanding run.. sorry I’m the real layman, I guessed some of them and other I thought were really important to know if I was going to get the job done right. anyway I hope this helps. Fingers crossed for me, I’m going to have fun trying to explain what a buffer is in french with a special flat aluminum-sanding disk. I’ll send you before and after photo’s if you like. Alex Answer: Dear Alex I just got back from my fishing trip, when I saw your email. Thanks for the support and the compliments. As to the flooring terms, sorry about that, but I had to write these articles for pros and semi pros, and I guess it’s a lot easier to use the professional terms for these items. But, for sure we are going to be writing a wood flooring dictionary. And I will probably re-write yet again that floor sanding article to make my words perfectly clear. I do appreciate the feed back. Anyway here goes. The feathered edge of a floor sanding machines drum is the higher side as it sands the floor. If you take the time to tune up even a rental floor sander, you will see that when you lower the spinning drum to the flat sandpaper held to the floor (as I suggest in the article), that the drum either sands perfectly flat or very very slightly to one side. You will always want to either adjust the machine to sand perfectly flat, or I prefer to have it slightly tilted. But a slightly tilted drum has to travel (as you sand row after row of the parquet) so that the feathered (high side) of the drum sands the floor last. So this dictates the direction of travel when you sand the room. You start on the right side of the room, and work row by row to the left it the drum is sanding high on the right side. Whew ! I don’t think I could explain that any better. But to tell you the truth this is not that important with parquet, as you will be sanding the floor in both directions, so any errors will be somewhat canceled. The anti-vibration belts are available at http://www.leevalley.com/wood/page.asp?SID=&ccurrency=1&page=30051&category= 1,240,41067 But again Alex these are only needed by the dedicated wood floor professional, and in your case the rental machine may not really benefit from these link belts. By cinching, I mean, when you attach the sandpaper to the drum, there is a dual roller system inside most drum sanders, that has to be tightened (or cinched) carefully in order not to create a flat spot in the drum. As you can imagine this will create chatter marks. If you are lucky your rental drum sander will have a sleeve of sandpaper that just needs to slip over an expandable drum, but only on the newest machines. And “chatter marks” are the bane of every floor mechanic. You can commonly see these marks on freshly milled unfinished wood at a lumber store. Particularly on really wide boards. These are seem as regular stripes or waves across the grain of the wood. On wood floors they will also show up when you stain the floor as undulations or waves in the finish. But you are lucky, these marks rarely show up in parquet (the wood grain orients in both directions). You will be screening (or buffing) the floor on the last sanding anyway, these marks will be kept to a minimum. Oh, and the long and short sanding run, refer to the fact that when you sand a long room, you will be able sand off 2/3 or more of the room by running the machine in (row by row) one direction. To your rear there will be a shorter piece of unsanded floor, that you will get to by turning around, and sanding this section (row by row) until the floor is completely clean. Now with the next pass of finer sandpaper, you need to reverse the short and long sanding sections of floor. Just start from the where you did the short run, but this time do 2/3 of the floor area sanding in this direction. But again Alex, this is less important with parquet, except on the last two sandpaper passes. Because (as I wrote in the article) the second sanding is done with in the opposite direction in the case of parquet. And then the final two sandpaper grits are done in the original starting direction. So, start North to South with 36 or 40 grit sandpaper. Then use 60 grit to sand East to West, and then finish off with 80 and the 100 grit papers (going again North to South and then South to North, this time reversing the long and short runs. This all keeps the machine marks randomized, and not visible when applying the stain. And don’t forget to buff the remaining sanding marks out with the large floor maintenance machine. Here is a web site that sells such machines, the Alto Sander 1600 or 1700 is the one you want to use, or whatever you use in France, with 100 grit screens or double sided floor sanding paper. Go to http://regalequipmentonline.com/alto5.htm The flat aluminum disk is used on such a machine as it stay’s level and does a great job of removing the cross grain scratches of the big drum sander. But you can do it with just the standard rubber and wood or fiber pad provided by most tool rental places. Don’t worry too much about all these details, this is your first job, I took me almost 6 months of full time work to create well surfaced floors, just get to it. You could always hire a pro to do all the drum sanding and edging and do the final buffing, staining and finishing yourself. I just try to be realistic about the difficult and complicated nature of these jobs in my articles. I don’t sugar coat the truth. Good luck, I hope this all helped. And sure, please send me some before and after pictures, by email if you could. Post it if you have to the address is below. Any more questions you may have on this subject or clarifications of your original question feel free to write again at no cost. I hope you have enjoyed this personal service, real human responses are the best. As always your Most humble servant, Joseph, the Wood Floor Doctor.