Question: Never use OSB, chipboard, or any type of particle board, as the nails will loosen and floors will squeak. I did not know this and this is what my contractor used when putting down my floor. How can I fix this? I hope there is an answer? Rich Answer: Dear Rich I can only make the following suggestions if you have not yet installed your hardwood floor over the OSB. At the very least you should nail down 5/8″ plywood (over the OSB) hitting the joists with 4″ spiral nails. I say this is the least because the hardwood flooring nails will still penetrate the OSB 1/4″. But I would hope this would not cause too many squeaks in the future. And this will keep from raising the final floor level too much, so as making too high a rise to the various stair cases. But 3/4″ plywood would be better, as the flooring nails will almost only contact the plywood, and be as if the OSB wasn’t there at all. And the very best thing to do is to remove all or most of this substandard building material (OSB) and replace it with 3/4″ plywood, or even 1 by 4 Southern Yellow Pine laid diagonally to the joists. This last suggestion makes the very best nailing surface for hardwood flooring, if you’ve got really deep pockets. But if you have already installed the hardwood over the OSB, be sure to keep your house relative humidity within 40-60 %, and hope for the best. If you find squeaks develop before your new home warranty is up, but sure to complain early and often to the builder. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Two years ago we had 3/4″ oak floors installed in our new home. The oak floor was installed over OSB rough flooring. This floor is supported by a truss floor, which has some give to it. The problem is that the floor pops when you walk over it. Is there any way to eliminate this popping? Dwight Answer: Dear Dwight It is very likely that the OSB is the problem. This material is just about the worst performing subfloor yet made. Often during construction the OSB will get rained on and swell along some or all of it’s edges. Once the roof is on and the subfloor dries out, it doesn’t settle down entirely. The builders make an attempt to nail down and sand down the edges, and this might be fine until a hardwood floor is mistakenly installed on this rather inferior nailing surface. Then two things can happen, either the hardwood floor nails or the subfloor nails loosen in this material and start this popping. Or in rarer circumstances the OSB fibbers that have been water damaged start to break and create most likely what you are hearing. The good news is that if the later is the case, the damaged fibers will in some time all break and the floor will quiet down on it’s own. But I’m not sure what the floor nails are gripping into by then, sawdust? By all means have the builder take a look at the problem, and be sure to keep track of when the problem started. Most new houses in North America are covered by a new home warranty, and this sort of thing may be covered. There are a couple of solutions. The best is to remove all the hardwood and OSB and replace the OSB with 3/4″ plywood glued (with a urethane adhesive) and nailed (with 3″ spiral nails) to the joists. Do this for the whole house if at all practical. At least do that in the problem areas. If it is just going to be only a patch job you will of course only be able to use the same plywood thickness as the OSB. In either case you will have to replace all or do a major repair on the hardwood. If it’s prefinished (you didn’t say) make sure it matches the old floor. But if it’s sand on site, make sure that the whole floor is resanded to blend this job in better. You may need to be compensated for having the floor resanded, as this removes about 1/6 the useful life of the floor. You may try a product called Squeak Enders at http://www.squeakender.com. This may provide a temporary solution to some the worst areas, but you have to have access to the underside of the floor. Let me know if cannot get under the floor, and I will teach you a re-nailing technique from the top, once I know what kind (site sanded or prefinished) wood floor you have.

Question: Dear Customer service, I am looking to purchase a stand up floor orbital sander. Is there such a thing or something equivalent. We are currently using a Clark orbital portable sander but find it hard to use being in a bent over position etc. Is there an up right model that can be pushed along the floor Please advise, Thanks, Chris Pettinger Answer: Dear Chris Go to http://www.regalequip.com/Alto/clarke.htm and scroll to the bottom of the page. The last two sanders are what I think you want. The last one is the random orbital sander (OBS 18), and I wrote about this machine in the Case In Point section of this site, be sure to read this review. The only other limitation of this machine is that the orbital bearings wear out prematurely. Maybe by now Alto has sorted this problem out, but 3 years ago I saw a table full of worn bearings in the back maintenance shop of the Home Depot. The company kept supplying the parts, and they just kept wearing out. The maintenance guy was quite frustrated. Now the second to the last machine (3DS) is rather new. I’ve never seen it. But it looks like a conventional buffer to me, with the addition of the vacuum, and the wheels. This may be more to your liking. 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: I have an old house (1914) with beautiful pine flooring. What about stripping, screening the floors and using pure tung oil for a finish? The floor has some type of poly on it now. I have read and been told of the good water resistance of tung oil and the ease of repair to the finish. Rick Answer: Dear Rick Well sort of. Pure Tung oil no, it has little water or wear resistance and shouldn’t be used as a floor finish at all. All varnishes are made of various oils, and it’s their ability to harden into a film that will make them water resistant. And Pure Tung has a limited ability to cure or oxidize into a film that will protect the wood. Now don’t get the idea that because the tung oil is absorbed into the wood, it is protecting it. This is not the case, and with water spill the water will go right through this type of finish. Now that all said the finish you now have on the floor may still be savable, but to find out please read the wood floor maintenance article in the Floored News section of this site. It’s always best in any case to recoat an existing finish with something that’s generically the same. And Oil Modified Polyurethane comes in a satin finish, that will not make your floor look like it has a plastic coating on it. We have a Pro Series article on just how to apply this poly without the bubbles or pits that most people get. Now that all said if you want to sand the floor to the bare wood, and still use an oil/varnish type of finish, there is a brand out there (Tried and True ) that is truly non toxic, and does form a cured film of sorts. Now, this finish is really made for the furniture trade, and you will have to apply 5-6 coats over 2 weeks to build enough of the film to make the wood glow, but it can be done. Visit their web site at http://www.triedandtruewoodfinish.com and check out the oil/varnish. It is probably one of the more durable of the oil/varnishes and at least it is quite non-toxic to use, so the touch ups will be helpful to the floor, but harmless to you. Let me know if your want the detailed instructions on how to use this type of finish, the method of floor finishing with an oil/varnish is a lot different that what they suggest on the can. Oh, and if you want to strip off the poly there is no need to sand, just read my Chemical Stripping Wood Floors article. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: I have bleached oak floors that I want to have sanded and refinished. Two quotes were obtained. One swore by oil based the other by water based. What are the pros and cons ? Are there major differences? Price? Answer: Dear Laura, I’ve sworn at both types of finish. But you mentioned that you have bleached oak floors, and I presume that you want to keep them white in colour. In that case you really should use a water based finish. You should make sure that the contractor applies at least 4 coats of good quality finish as this material has a lower build than oil based finishes. I recommend the Dura Seal 2000 (800-364-1359) for it’s long lasting clarity, or Basic Coating’s Impact (800-247-5471) if you need exceptional durability, and the Bona Kemi product called Pacific One (303-371-1411). You really should call each manufacturer and get their lastest recomendation of just what stain to use with their finish, they are improving these finishes all the time. These are very expensive finishes and if I were to quote on sanding, white staining and applying 4 coats of water based finish, the price would be around $4 per square foot, as opposed to a dark stain and 3 coats of oil poly at $3.50. Water based finishes are only about 10 years old and not all the contractors have adapted to their new application methods, so you might find lots of resistance out there. If it is a dark stain or just a clear blond finish you want by all means use the oil based urethane, the job will be less expensive and just as durable. But as oil based finishes age they will turn a yellow to orange cast, which would be really noticable on a white stian. If you choose the correct water based for clarity and durability you will have minimal ambering effect over the years, but call those numbers and get their current information. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: What are the pros & cons of an oil/wax finish vs. urethane? This will be applied to a new maple floor in a low traffic living room and a high traffic hall. Mike Answer: Dear Mike There are almost no oil/varnish finishes out there that are durable enough for floor work. But here are two : http://www.triedandtruewoodfinish.com and http://www.waterlox.com. The tried and true true oil/ varnish is really meant for furniture, but is truly non toxic. And the waterlox brand have finishes that are more like varnishes than oils, but are suitable for floors. You should not use a pure oil finish on a floor, as it will have no water resistance. These oil/varnish blends are the best of both worlds, but are difficult and expensive to apply, so would cost a lot more than a regular oil modified polyurethane finish. They have the advantage of easy touch ups, but any dent or scratch will still show through.They should not be waxed as is often the suggestion. You will be defeating the purpose of the touch-up-ability of these finishes. Once the wax is applied (any floor finish has to cure for at least 1 month) you can only touch up with wax, not the floor finish any more. For all of my floors I only use oil modified polyurethane. It has a fairly quick dry. I apply one thin coat and by the next afternoon it is dry enough to be scuffed, and the second coat brushed on. I skip a day and scuff again and apply the third coat. It’s ready for moderate use in 48 hours, and cures in one month. The finish will get harder over the years, and should last 10-20 years in light use areas. It’s easy to re-coat, but cannot be repaired invisibly, any touch up coat really show, unless you do the whole board or wall to wall. Compare that to the oil varnishes. You will need to apply at least 5-6 coats of a true oil/varnish, and this will take about 2 weeks to let each coat dry enough to be steel wooled. Don’t be fooled by the fast dry times of some company’s instructions, they say that the OMP that I use dries in 4 hours, it’s simply not true. And the oil/ varnish finish will not be as scuff resistant or as durable as the OMP. You will find yourself recoating this floor every 2-4 years to keep it looking good, and only of you use the Tried And True finishes will you have a real non-toxic finish (no heavy metallic dryers), and this will cost you a bundle over the years. With the waterlox brand I’m afraid you will be exposing yourself to lots of toxic fumes as you touch up and re-coat these floor so often. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: white oak floor, stain and two poly. poly is starting to blister at board edges and ends. also, painter’s blue tape would pull up finish after being down for ten minutes. what is causing this? Answer: Dear Frank You are a man of few words, but I do believe I know the problem. If it was a new floor, the fact that the wood white oak wouldn’t have affected the results, unless it was a water based stain. So, I’m surmising that you used an oil based stain, and let it dry according to the directions on the can. But the trouble with most can labels directions is that they may not take into consideration that you are staining a floor. A wood stain that will dry in 24 hours on a table, can take from 24-72 hours to dry on a floor. The large area, and the fact that floor will hold a lot of stain, makes these areas dry quite slowly. Now, if the stain wasn’t fully dry the still wet oils on the floor would not allow the next coat of poly stick to it. And there might have been a clue to this if the poly had bubbled or pitted a little bit. If you did not scuff sand this coat the last coat would have also not adhered well, but may have also looked OK. This is especially true for these newer fast dry polyurethanes. The best way to determine which coating is not sticking, is the finish adhesion test. Using a razor, cross hatch the finish down to the bare wood, after it has cured for 30 days (to be fair). Apply a piece of duct tape and rip it off. If more that 20% of the finish is peeled off you have a failed finish. But, look more closely. Is it peeled down to the stain or just the last coat. Chances are it will lift to the stain. So, I hate to be the one to tell you this, but in the case finish that didn’t stick to the stain, you will have to sand or chemically strip the floor to the bare wood and start all over. This time use a professional quality fast dry pigmented wiping stain. I use a locally made stain that the can label says will dry in one hour. But I let it dry overnight, and for 20 years I have not had one peeled finish. But if you discover it was only the last coat of poly that didn’t stick to the first coat, and after doing the adhesion test you find that most areas are OK. You could TRY to screen off most of this peeling last coat. And recoat again. But this is risky. You will have to use a 100 grit screen on a buffing machine, and do this fairly aggressively. The trouble is that some of the stain may come off in the process, and you will have to do a lot of touch ups. This may prove to be so difficult that it may be better to sand or strip the floor all over again, to avoid further problems. Most professionals do not use fast dry polys. And we always allow for long dry times between coats, and screen (scuff sand) between coats of poly. In fact I have written the difinitive article on exactly how to apply oil modified polyurethane without the bubbles or any adhesion problems. It’s not easy or quick (8 pages) but my methods have proven themselves over 20 years of hard use. I’m sitting on one of my 20 year old poly finishes now. I will tell you even what brand of poly I use right now. The Fabulon Heavy Duty poly satin. And in about a month or so we will post articles on how to sand a floor to ready it for the stain, avoiding machine marks. And yet another article on the 4 different varieties if stain I use to color different species of wood. You see this is not a 1-2-3 big orange box store web site. I will tell you all that I know, if you care to learn. If you have followed the direction on the can label to the tee, and have at least one witness to attest to this fact, you may have a strong case against the manufacturer. In some cases some finish makers have paid for the resanding of the wood floor by a professional, and have refunded the cost of the finish. But you will have to be persistent. If it was new wood, there will not have been any contaminants in the wood so this would not have been a limiting factor. If this was an old floor however, and you did not sand it well enough to the bare clean wood, well this is another matter altogether. But the solution is the same for all cases, sand to the bare wood and do the job again. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Hi Doctor, We have started construction on our expansion/renovation. As you see below, you advised us to go with oak if we go with a wood floor in our kitchen. We also are considering hickory, if we can get the darker heartwood. What do you think of Hickory? We also are going with radiant heat. Does that change your recommended preparation/installation? What about plank width? We like the medium width, say 4″ to 5″. Is that OK? Any recommendations as to where to get the flooring? Appreciatively, Jon Answer: Dear Jon Stay away from the wider sizes of hardwood floor. These will just expand in the summer then shrink back in the winter heating season, creating ever widening gaps. Stick to the narrow 2 1/4 and 3 1/4″ sizes, and make sure you have a good well renailed subfloor. Never use prefinished floor in any case. All the open seams of prefinished floor are just an invitation to water and dirt. There must be plenty of good floor sanders in NYC and one the Hickory or Oak floor is installed, have the floor professionally sanded, and then consider doing the 4 coats of poly yourself. There is a good reason for this. You may find it difficult and expensive to hire someone to apply the 4 coats of poly you need for a water repellant and durable floor finish. And seeing how you will be recoating the floor every 2-4 years to keep it water repellant, you really should do all of the finishing of the floor yourself. But never the sanding, with those awful rental machines. The finishing of the floor is the fun and rewarding part of the job anyway. If you want an article that will walk you through the use of Oil Modified Polyurethane, we do have an article on it found in the search box at the top of the web page. It’s very detailed, and will teach you how best to apply the poly without bubbles and pits that most people experience when using this material. Well worth it. Oh, and because you are going to heat the floor, consider even a thicker subfloor (1″ plywood) and consider using only a clear quarter sawn grade of white oak. And also consider applying one or two coats on the underside of the wood a week before it is installed. If you can get the same grade in Hickory this would be fine also.

Question: My contractor recently installed a new select oak floor in new the new addtion for a kitchen. The boards are about 2 inches or so in width. They were stained and polyurethane applied. Subsequently my entire large kitchen was installed, cabinets, granite, appliances and then we noticed the floor was not flat but was wavy. Each board is buckling upward slightly at the intersection with the next board. It is nearly completely symmetrical with a subtle wave going thoughout the kitchen. My usually excellent contractor admits that this is a problem and is bringing in a wood flooring expect to look at it. The floor is constructed with sheets of plywood nailed to ceiling joists of the new garage below. On the plywood is 2×4’s about 6-12″ apart with an additional piece of wood on the 2X4 to increase height above the plywood. In between the 2×4’s, is tubing for radiant heat(which has not been turned on). The oak floor is then installed crosswise on the 2×4’s. What could have caused this? Is there any repair possible other then ripping out the entire wood floor which would be astronomical being that the central island alone is 6 ft by 8 ft with plumbing, granite and applicnaces installed not tomention the 600 lb range and 700 pound frig. Gary Answer: Dear Gary Don’t start removing any floor YET, the problem may sort itself out, if you are really, really lucky. The cupping of the wood was caused by excess moisture during the construction. The first thing the flooring expert will do, is a moisture test of the floor, with an electronic moisture meter (one without the pins). If the floor EMC (equilibrium moisture content) is above the average for your area, it still contains excess moisture in the wood. The floor will have to be allowed to dry out on it’s own. Check first for any pin hole leaks in the pipes below the sink or the even the feed pipe to a ice maker on the fridge. This cause is doubtful as the result would be a localized bucking. Whereas you have a uniform cupping. Most likely the mistake was made in installing the wood floor too early on in the construction process. If the hardwood was brought it at the proper EMC (check this from the supplier) and then was installed over air dried lumber, and drywall and concrete curing in the garage below. Well you can see that the wood flooring is hygroscopic and might have taken on the moisture from all these sources. It may even have developed a slight crowning just before the floor was sanded and finished. If the crowning was sanded off before the wood got a chance to correct itself, when the floor did flatten itself the cupping effect you see now then might have occurred. This is all a bit of a guess from where I’m sitting but it is a common occurrence on new construction. It’s up to the hardwood flooring contractor to bring in the wood only when the job site is ready for it. The job site is ready only when the concrete slab below is has cured for a least 60 days. And the drywall has been taped and primed and dry for at least a week. All framing members under the floor including the plywood subfloor has to have a EMC about the same as the new hardwood floor. Air dried construction lumber really needs a month or more to dry out, and it’s better to wait until the AC or heating system is on to speed this drying process. Also I should mention, now that you’ve read the Hydronics article, that it would have been wise to install the floor during the heating season. And using quarter sawn wood is just the thing in this situation. I commonly install my wood floors around existing kitchen cabinets, using the kick boards to cover the expansion space at the edge of the floor. In fact that is the ONLY way I will install a kitchen wood floor now. I’m just about to install such a floor starting Monday. It makes no sense to have the wood under the base cabinets. It traps the wood in a place where it has no room at all to expand. If it ever does buckle it may actually lift a base cabinet off the floor. Sure installing the floor early on is easier for the installer. But given what you are now experiencing, it makes no sense to me. So that’s the mistake. Now for the solution. Don’t do anything until the heating season starts. Follow my suggestions as to turning the heat on gradually and see what happens to the wood. If what happened is what I have mentioned before and the wood is now at the proper EMC turning the heat on this Fall will not help. So, if by Christmas the wood has not settled down flat, you can either sand it down flat again, or consider replacing it. Sanding it flat is a viable option, because if my guess is correct, the underside of the wood is now also flat. And now only the top is slightly cupped. Sanding the floor flat in the heating season will make both sides flat, and as long as the garage is heated also, both sides of the floor will have the same EMC, thus no more warping. But if you want to replace the wood, this time follow my advice in the Hydronics article, using thicker plywood. The thicker plywood will keep summer time humidity from contacting the underside of the hardwood. You can see if you AC the space above, and have the garage hot and humid similar problems can occur again. In fact while I’m thinking about it, this may have had a factor in the cupping also. Especially if the kitchen was AC’d weeks before the sanding and finishing of the hardwood. If you choose to replace the floor, there is a way to cut the hardwood out of these tight spots and remove it. We do it all the time on old kitchen floors. We use the Fein Supercut saw, to plunge cut easily and accurately right down next to a base cabinet. It won’t harm the base and the cuts are smooth and perfect. The new wood is installed (quarter sawn hardwood this time I hope) using proper expansion spaces. You may have to undercut parts of the base cabinet using the Supercut saw. The job will be laborious and difficult, but worth it in the end. Oh, and if a thicker plywood subfloor is not in the cards, under coat the hardwood as suggested in the article. Sanding and finishing a job is no picnic either, but I do it all the time. We have methods and tools to sand floor smoothly in the tightest of spaces. This is a typical job for me in modern houses. But not cheap. Well, I hope I have covered it all!

Question: I plan to install a hardwood 5/16″ laminate pre-finished floor over an existing 3/4″ plywood subfloor. I plan to screw the subfloor down. My problem is impact noise traveling from this kitchen floor to a bedroom below. I intend to install the flooring as a floating floor. Where can I obtain a soundproofing mat to put under the laminate flooring? I have found a 2mm sheeting in England but that is a problem in California. Is there a USA firm that makes a thin soundproofing mat? I can only afford about an eighth of an inch due to appliances. I would like to use two layers if possible. Answer: Dear Tom You must make sure you are installing the type of engineered wood floor that can be done in a floated method. I’m not really fond of this method, as the PVA adhesive used to glue the panels fails after about a decade. And then your floor really will sound like a drum. It would be better to glue down a cork sheet floor first using Dri-Tac 6200 adhesive. Let this cure for a weekend then install the laminated wood floor by gluing it to the cork with the same adhesive. The other reason for gluing down the floor, is the fact that it is a water prone area. Kitchen spills will eventually find their way under the floating floor. This is where molds will form. Whereas the adhesive I speak of is waterproof, and the water cannot travel past the seam. That said, the Dri-Tac adhesive has proven to last at least 45 years and counting, and it is still tacky. It remains sticky all it’s life so if the floor moves out of place expanding during humid weather the glue will pull it back when conditions dry. This is the only glue I will use for all my glued down wood floors. You may find that a glued down floor is less noisy that the drum of the floating floors. In any case the foam pads they sell for the floating floor will degrade in about a decade. You can buy cork sheeting at just about any home improvement store, and the Dri-Tac 6200 is found there too. But you may have to search for this good glue. Try the web site at http://www.dritac.com. Oh, and don’t expect too much sound proofing with this little bit of pad. Real soundproofing has to be done from below, but this is another matter. You should also read the first part of my floor maintenance article in the Floored News section, to get an idea on how to re-coat this type of floor. Kitchens floors take a real beating and need lots of maintenance. As always your Most humble servant, Joseph, the Wood Floor Doctor.