Question: What is the industry standard for joint spacing across rows of floor planks? Answer: Dear Diane I’m not sure if there is an industry standard. It is really an aesthetic issue. But in general it is best not to have 2 joints closer than about twice the width of the boards themselves. So if you have a 2 1/4″ wide strip try to have the joints of two boards no closer than say 4-5″. And I mean two boards, because the next ones should be farther and farther aprt, so that you don’t set up a stairstep effect. It takes some years to master this technique by racking up to 8 rows of strips across the room. Then take the time to add and subtract pieces until the joints are pleasingly spaced. And you should avoid H joints where the joint is lined up with another joint, with just one row between it. All this said, everyone, (including me) will make minor mistakes in this pattern. In most cases it will be hardly noticed once your furniture and rugs are in. But if the floor is full of these busy, unsightly joints, it may be the installer who has let you down. In many cases he is paid very little on piece work basis, and will rush through your job, just to make a living. This has become the industry labor standard, sadly enough. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Hello, I am a craftsman who installs floors, and have used water base catalyzed polyurithane, because I considered it less toxic, and have thought it to be easy to use. I see you list as a con of WBP, that it is toxic, could you tell me more on this? Thank you, Ben Answer: Dear Ben While certainly you are exposed to less fumes as you coat the floor, some of solvents in this finish can cause dizziness. Read the Dura Seal article in the Floored News section for more about these mildly toxic solvents called glycol ethers. But the real fly in the ointment is the azridine catalyst or hardener, that is supplied with the commercial water based finishes like Street Shoe and Traffic. I attended a seminar at a fancy hotel given by Basic Coatings here in Toronto about 15 years ago. They were demonstrating the Street Shoe product, and I saw the factory rep don rubber gloves up to his elbow, before he snow plowed the finish. At the time I found it quite alarming, and the few times I needed to use this finish, I also used rubber gloves. But I didn’t know why. I had thought the little bottle of azridine was poisonous by not too deadly. Well now I know better. This stuff is a confirmed carcinogen, and when absorbed through the skin ( it easily does) causes tumors, and prolonged exposure to this seems to cause skin reactions, and allergies. You should never pick up a bottle of this stuff with your bare hand. And be careful not to splash it on yourself or your clothes. I only will use it (street shoe) as a substitute for MC poly, and only for commercial jobs. As I do almost all residential jobs now, I have thankfully not had to use this stuff for years. The MC poly was deadly to my lungs and I almost died after getting a lung-full of the xylene and toluene fumes years ago. But If I were you I would switch to the safer oxygen cross linking variety of water based finishes, as described in the Dura Seal article. Oh, and the other water based finish catalyst called Carbodiimide is fairly safe, but makes a much weaker finish ( as in the flecto renewal system). But if you want to avoid handling the azridine, you should try the Dura Seal 2000 water based finish system. It has the hardener in the cap, and you puncture this seal on the cap and let it flow down into the gallon without touching it. The Dura Seal rep in Texas told me that once the azridine is in the finish it is harmless. I’ve heard nothing to confirm this other than from Dura Seal. So I will still wear rubber gloves to apply and clean my applicators. This method doesn’t allow you to use a partial gallon of course. I don’t think it’s selling that well just for that reason. I should mention that I suffer (not too badly) now from Hairy Cell Leukemia, which is a rare, and rarely fatal blood disease. And I can’t help but think back on all the chemicals I’ve handled over the last 24 years, and wonder why me I’m just in the middle of writing a health and safety article for this web site, and I wonder if anyone will bother to read it. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: I’m very confused now due to I spoke with a hardwood manufacturer (BRUCE) and they (technicans) told me this was an approved installation and was even listed in their installation manuals! I trust that the information provided by you is correct therefore I have full intensions to contact the contractor and recommend that he start ripping the floor up. (this happens to be an insurance claim anyway)! Sounds like you are very experienced in what you do. Thank you again for the valuable information provided. Shellie Answer: Dear Shellie It matters not what the Bruce manual says, this is not the way to install hardwood floors. Else we would all have many layers of hardwood in old houses. It’s just the cheap way of doing it. The bruce guy was probably reading about installing on old floor boards, and these he has mistakenly thought meant any type of wood. Softwood takes nails well with out splitting, That’s why it is used in all framing and subfloors and sheathing. Any carpenter know this. It’s not rocket science it’s just common sense

Question: I am thinking of using yellow pine floors in my new home. I know this wood is softer than the hardwoods, but I love the look of the pine. I will be using the gel stain as recommended on your site. Could you please recommend a manufacturer’s finish and gel stain. I believe I will need a polyurethane finish for durability and easy care. I would like to use the best available on the market. Thank you very much. Answer: Dear Nina I rarely if ever stain pine floors, but if you, must try the Old Masters Gel Stain available from Lee Valley, my favorite tool supplier at http://www.leevalley.com/wood/page.asp?SID=&ccurrency=1&page=45091&category=1,190,42942. This will get you right to the page you want. This is a good, reliable mail order company that I have dealt with for more than 15 years. Oh, and if you can afford it, the Southern Yellow Pine cut from old growth timber is very tough stuff, but does dent easily. We have Eastern White Pine here as original floor in the Victorian House I live in, and while it dents really easily, it has made a fine back bedroom floor, finished with 4 coats of poly. Now that all said, the best finish for pine, and particularly over a stain is the Oil Modified Polyurethane, and the Fabulon brand heavy duty satin finish is the best I’ve ever used. I use it for almost all my floor finishing these days. But like anything there is a real knack to applying this stuff without the bubbles and pits people normally seem to get even with this fine finish. I have written an article on just how best to apply this finish. Use the search box at the top of the web page and type in ‘bubbles and pits’ to find the article on this topic.

Question: I have decided to go with a solid wood floor over plywood. There are 2 commonly accepted methods of securing the plywood to the slab, powder actuated nails and glue (mastic, poly, 4×4′ kerfed plywood). The second method is attractive because I don’t have to bother with powder actuated nails. Are there any disadvantages to the plywood gluedown method? I’m sure that some of the glue will fail over time but is this really a problem? Alex Answer: Dear Alex Well the reason I didn’t mention your proposed method in the web article on slab installations is the fact that plywood sheets are rarely flat and neither are concrete slabs. The bigger the sheet of material you want to glue down, the more of a problem this becomes. I would like to see slabs perfectly flat so the glue will sick and stay, without being stressed when you walk on it. If these plywood subfloors floors fail (a void starts popping) in any spot they will create a difficult repair job. But I guess this method is done in the flooring industry, a trade fraught with bad tradesmen and methods. So here’s what I would suggest. Certainly saw kerf the first layer of plywood and use 4 by 4 foot sheets. Lay the plywood kerf down side in that double layer mastic method you speak of. Glue trowel size is really important, spread the correct amount. I might say at this point that the new urethane adhesives are touted to be totally water proof, so I really feel that the poly layer in this case may be redundant. Just do a really smooth even glue troweling. Then use full sheets of plywood for the next layer, and lay this at a 45 degree diagonal to the first layer. The top layer of 1/2″ plywood doesn’t need a full troweling of glue, just spots or squiggles of the adhesive around where the screws will go. The 3/4″ wood screws installed every 1 foot square on the top layer will then smush these together quite effectively. This mixes up the more numerous joints that the 4 by 4 plywood has created. You should have no joint in both layers of plywood that go together. Joints should be kept about 1/8″ apart for expansion in both layers. With the top layer diagonal, and the new floor running straight you shouldn’t ever have any problems, until this glue fails in about 50 years. Oh, and let’s discuss the glue. It should always be a urethane adhesive as they contain no water. Find one from Bostik that will be suited to this specific application. As you are doing the first layers of glue make sure that each one is fully dry before you apply the next layer, or like I said skip the poly film altogether. Here is the Bostik glue link http://www.bostikfindley-us.com/products/index.asp?fa=subCategoryPagesx=2x=2x=49x=31 If you are doing this in a really dry climate, urethane adhesive won’t cure very fast below an EMC of about 8%. So we always in these cases spray the slab with a light mist of water. A LIGHT mist. But check the glue makers to see the formulation that works the best in your climate. They sell this stuff in tubes also, and be sure to get the special hand cleaner, or else your hands will be black for days. Good Luck. By the way I have to go into the hospital tomorrow, so I will be unavailable for at least 2 weeks.

Question: Dear Doc, I will seriously look into unfinished floors. However, I have read that pre-finished floors are much better finished (in clean rooms etc.) and on-site staining and varnishing can be adversely affected by dust. Who would you suggest I use for doing on-site finishing in the Montreal area? Muneeb. Answer: Dear Muneeb In your case the unfinished is the answer, and any responsible supplier would confirm this, in a case of an uneven subfloor. Some suppliers may have a warehouse full of prefinished flooring that they need to move. That’s why they mention these floors are adversely affected by dust. A lot of airborne dust is created during the floor sanding process, but I just applied the final coat on one of my own floors a few days ago, and it is as smooth as glass. How do we do it? Simply hire a professional for the floor sanding at least. Then simply vacuum up all the dust, from the floor and any ledges. Apply one thinned coat of polyurethane. Wait 1-2 days for it to dry at 21 C. Scuff sand the floor smooth, vacuum and tack rag with varsol. Allow solvent to dry. Apply a heavy coat. And repeat the same thing for the last coat. Always brush the finish on with a good quality 4″ bristle brush. It’s not rocket science but you may have to ask quite a few contractors before you find one willing to do such a thorough job. That’s why I suggested you apply the finish yourself. If you want about the same durability, you can try the water based finishes instead, so be sure to read my article about Dura Seal 1000 finish available in the search box at the top of this web page. Oh, and if you were considering stain the floor, I would instead find a pro to do the whole job, sanding, staining and finishing. This is far too tricky a job for the amateur to tackle on a weekend job. Whereas the pro will recognize the sanding marks that have to be removed so that the stain will take evenly. And it is very easy t pull the stain off when coating the wood. Be sure to have 3 coats of poly applied over the stain. Read my article in the available in the search box at the top of this web page about how to hire a contractor. Be sure to see the prospective floormans stained jobs before you choose a company. Expect to pay quite a bit for this rather specialized service. Also be aware that only oak and a few other woods take a pigmented stain well, maple will turn blotchy.

Question: Is it possible to install a hardwood floor (2 1/4×3/4) oak strips in the same direction as the floor joists over diagonal planking sub-floor in a 50 year old house? The existing oak floor needs patching because of the original closets and wall that I removed and I would like the floor to match the room adjacent to it so I am willing to rip up the old floor and install a new one in the opposite direction. Room size about 15’x 12′. Eugene Answer: Dear Eugene No, in you case it is NOT OK to install the floor parallel to the joists. If you step on one of those diagonal boards, you will see how much it flexes. This is because it spans as much as 25-30 ” corner to corner. If you want to install the floor this way you will have to add a layer of 1/2″ plywood nailed to the joists on top of the board subfloor. And even then you have add 1 1/2″ wood screws in between the joists to keep all these layers from squeaking later on. It is best to install the new floor crossing the joists. And re-nail most of those old subfloor planks in any case, they will cause no end of squeaks later if you don’t. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: I am having hardwood floors installed in my living room, front entry way, and dining room. The entire area is currently covered with a single layer of well-installed linoleum. My preferred contractor says that he would recommend installing over the linoleum – that it will result in a better floor, less squeaks, and will hold the nails/flooring better than whatever subfloor is beneath (plus, of course I think of the additional cost and mess). Is this a legitimate approach? Also, I have a dog, and am trying to decide between prefinished and sanded in place. I like the sanded in place look better (no microbevel), but wonder if I’ll regret it in a couple of months time… Thanks Andrea Answer: Dear Andrea The best way to install a hardwood floor is to investigate just what all the layers of underlay and subfloor are made of. It does you no good in the long run to install a wood floor over an unknown subfloor. If you happen to find OSB or particle board in any of the layers, these will have to removed, as the flooring nails ( never use floor staples) will work them selves loose from these materials. That all said, I know it is more expensive and time consuming to remove the old lino. But you really only need to remove a small patch of it, to confirm that it was laid on a PLYWOOD underlay, and a PLYWOOD subfloor. If this is true just renail all the layers of plywood, subfloor and underlay with some really long nails that penetrate to the joists. This is the only thing that will prevent squeaks. And as long as the vinyl is the flexible kind it is all right to lay the hardwood on top. But like I said make sure all the layers under the vinyl are Plywood. And as to your last question, get a sand-on site floor, done with a finish that you can recoat yourself. For me it’s Oil Modified Poly. No finish in the world will resist the scratches, but the OMP will be easy and cheap to recoat. If you want to try a newer but as yet time proven water based finish, read my article in the Floored News about the Dura Seal 1000 water based finish. But in all fairness to the prefinished floors, you can read my Melrose article in the Case in Point section, and my new Prefinished article in the Floored News also. But the wood under these remarkable finishes will get dented by the dogs claws too. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: How do I install a strip floor with a herringbone pattern? Answer: Dear Dennis This type of floor is generally glued down these days. I suggest a very level, dry subfloor. It should be flat to within 3/16″ in 10 feet, or 1/8″ in 6 feet. Correct the subfloor if is not. A concrete floor needs to be moisture tested. Use only Dri-Tac 6200 adhesive (www.dritac.com). It’s the best. Oh, and make sure they are identically sized pieces, from a reputable mill (stored properly also) or they will never fit well. Find the center point of the room, exactly. Lay two chalk lines at right angle to this center to both walls. Test this with the 3′-4′-5′ triangle (remember the Pythagorean theory). You now have a large cross in the room, with its intersection exactly in the center. Now snap another exactly 45 degree line through this center. Next snap another chalk line exactly half the width of the herringbone board below this diagonal line. Dry lay the boards (without adhesive) to get a good idea of how it’s done. The first board is laid right on the line below the center diagonal and it’s end (and middle) just touching the center spot. The second one is laid and right angles and on top of this, and so on for three row up. Now lay the boards to the left along the line. You ninth board should be along this same starting line. Go up the diagonal line until you have dry laid about 20 boards. The make a rough pencil line around these boards, remove them. And now spread the glue. You should be able to see the chalk line through the glue, once it has tacked off (follow Dri-Tac’s excellent instructions). Relay the pieces in the same order. Allow the glue to set up on these 20 pieces for about an hour, then roll, then and wait anther hour until they cannot be moved out of place by hand. Now you can apply more adhesive in any direction you wish and continue, but try to fill most of the one quadrant of the room at a time. And be sure you don’t spread too much glue so that it dries and won’t accept the wood.

Question: We are building a new house and have chosen pre-finished hardwood for our bedrooms. The problem is that the plywood on the second floor does not seem to be leveled perfectly. Pre-finished planks will obviously not be smooth. Is there a way to level the floor before installing the hardwood planks ? Are these leveling compounds safe for our health? Muneeb Answer: Dear Muneeb It may be that prefinished is not the route to go. You can sand about 1/8″ off the high seams of the plywood, providing that it is at least 3/4″ thick. If you have a thinner 5/8″ plywood subfloor don’t do this. Don’t bother will all the claims of those leveling compounds, they will crack when nailed. And these are all really meant for concrete subfloors in any case. And the gypsum based ones are the worst of all. So don’t be afraid to sand off a bit of the subfloor, and install some shims. I like to use glued and stapled down 1/4″ plywood and sand off the edges to fill in dips of that depth. Then staple the plywood edges after. You do all this sanding of the subfloor with a floor edge sander loaded with 16 grit sandpaper. Then I would strongly suggest installing an unfinished hardwood, and have it sanded professionally on site. The first passes of the floor drum sander should be done at a diagonal to the run of the boards. This will level the floor perfectly. Consider doing the finish yourself that’s the fun part anyway. And in your case it may be the only way to get a really smooth floor. As always your Most humble servant, Joseph, the Wood Floor Doctor.