Question: Hi, I have asked you a question before on which wood floor finish is least toxic, and you have provided your answer for which I say “Thank you”. Now, I have another question. I have been told to go with ‘Moisture-cure urethane’, and with three layers…So, my question is “What can you tell me on how bad this wood floor finish for one’s health, or how good it is? Like anything that you might know, of it’s pros and cons?” Again, thank you very much… Felix Answer: Dear Felix I almost coughed up a lung last time I was exposed to the deadly fumes of Moisture Cured Polyurethane. This was really mean stuff. Back then this stuff contained up to 7% toluene, this is the stuff that glue sniffers die on. But it appears at least some companies have reduced the amount of this deadly toxin. Gerners has reduced it to 1% and that is much better. It will still affect the floor guys, and will be gassing off for up to 30 days after. And the bad new is this has about 50% Xylene, which is a skin irritant, but is also highly flammable. Read about similar flammables in the lacquer article in the Floored News. Frankly I wouldn’t touch this stuff. Yes, it is very hard and very clear (at first), but all the jobs we did got scratched up anyway. After 5 years it does amber quite a bit. And because it has to be applied by a pro, it is a impractical finish for home use. You cannot do touch up or re-coats yourself with this stuff. I speak from experience, we used to do commercial jobs with MCU all the time. But we switched to Street Shoe because of it lower toxicity, for us and the owner. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Hello I have a problem with a floor that we are going to be redoing. It has 2×10 floor joist and then tongue & groove 4″ flooring on top of that, on a 45 degree angle. Over that it has hardwood flooring that is about 60 years old. Then it is covered by glued down carpet. The floor squeaks every place you step. This is about 3000 square foot room and is to be used for commercial space. I will be removing the carpet and then reinstalling a commercial grade carpet on it again. I believe all the hardwood is just loose. Could you please advise me on how the proper way (least expensive and easiest) to repair and stop the squeaks? Thank you. Gerry Answer: Dear Gerry The least expensive is not the easiest and visa versa, here are some options: The three wood members; joist, subfloor and finished hardwood have separated, and the nails binding them now are moving in the loosened nail holes. This separation is generally caused by seasonal shifting of the boards, and you would be well advised to keep the indoor relative humidity levels to about 40-60%. I mean all year round. And sadly some hardwood floors were poorly nailed in the first place. If you can access the floor from under the joists you can try a nifty new product called Squeak-Ender at http://www.squeakender.com. They have several well-engineered solutions to squeaking and sagging floors, and it worth checking out. These products will save you from having to nail from the top of the floor, for the most part. The Squeakender’s web site has excellent illustrations of these products, so I needn’t explain further. You may however have to use some of the next described methods if these products are only somewhat effective. But with second floor squeaks and lack of access to the floor joists on a main floor just how can you re-nail a hardwood floor? You will need to find the joist that runs under the subfloor, so that when you re-nail the hardwood, it will pull the board down and stop the squeak. This method as you can imagine works best when the finished hardwood boards run at right angles to the joist. First find the where the joist run by removing the quarter round molding from the edge of the floor. Only remove the molding running at right angles to the joist. Drill a 1/4″ hole in this space (that the molding will cover) and insert a bent coat hanger. In either direction you will feel the hanger bump up against the joist. Measure over and drill another hole closer to the joist and test again, until you have determined the center of this joist. Do the same on the opposite side of the room, and snap a chalk line between the two. This should represent the run of the floor joists. They should in most modern houses run every 16″, but you may have to drill more edge holes to confirm this. If the room is wider than 15 feet, there may be a supporting beam separating two separate runs of joists. And they may not line up with each other across the room. You can only see this from below, even if you have to poke a small view hole in a basement ceiling. If you are unlucky enough to have the hardwood running in the same direction as the floor joists, you will only be able to re-nail one strip of hardwood every 16″ (as the joists are spaced). This will quiet a squeaky subfloor, but you may have to nail between the joist with 2″ finishing nails in a attempt to quiet the loose hardwood in between the joists. Once you have marked out all the joists with the chalk line, determine which side of the hardwood strips are the tongue side. You will want to pre-drill or nail spin ( nail spinners are a must at www.leevalley.com ; Prod. #99K20.01) a 3″ spiral finishing nail, so that this nail goes through the tongue side of the hardwood floor through the subfloor, and penetrates the joist quite solidly. This 3″ nail is only used for 3/4″ thick floors, use shorter ones for thinner strip floors. Use 2 1/2″ for 1/2″ hardwood and 2″ for the thin 3/8″ strip floors. Modern floor joists are less than 2″ wide so they are easy to miss, and you can tell when you are hitting the joists when the nails feels solid all the way in. Set the nail below the surface with the proper sized nail set, and fill with a colored putty. Use a colored latex putty that will dry hard if you plan on sanding the floor now. But use a soft non-drying colored putty and wipe off the excess with odorless mineral spirits, if you want to keep the floor finish intact. Choose a color just slightly darker than the finished wood. You can do this re-nailing every sixth board or so and see how it works. Then put more nails between these if you need to. Don’t over do it, or you will have a really pock marked floor.

Question: This installation is on a main floor room over a fully finished basement, so moisture shouldn’t be a problem. I am curious about your recommendation to use nails, and not staples? I have used a Stanley Bostitch MIII on many strip floors without a problem. Thank you again for the advice, Dennis Answer: Dear Dennis I presume you are a professional hardwood floor installer. And by many strips floors, you mean installing over 5-6000 square feet per year at least. You will eventually run into a case when a floor is exposed to humidity extremes and the staples will have stressed the tongues to the point of breaking them off. When it happens, and it will someday, you’ll find yourself liable for the damage. Very costly. The good news is that you can go to http://www.primatech.ca, and check out the floor stapler adapter, and use flooring nails in your same machine. The nails cost about the same as staples. I base my information on the Virginia Tech University study, in a simulated environment. The Primatech nail company repeated this experiment. And the Maple Flooring Assoc. has put out bulletins (to member only, not the public- the truth is out there) warning of tilting boards, and cracked tongues in their sports floors, using staples. The staples and the staple gun were developed for roofing originally. But roofers are going back to the coil pneumatic nailer, so the stapler was simply set on an angle to nail floors instead. The staple fastener was never designed for hardwood floors, but the serrated edged flooring nails were meant for only wood floors, and have been around for more than 50 proven years. The choice should be obvious, but don’t take my word for it, do your own research.

Question: We live in the Caribbean and we are in the process of building our home – an average sized family house 2800 sq ft. concrete structure. However I have always wanted a wooden floor in the fanily room and rather than the usual concrete patio (covered with ceramic or clay tiles) I wanted a wooden deck. Somewhere along the lines, this evolved into a covered deck, then a wooden floor over a concrete patio. Now the builder is telling us that a wooden floor would be impossible at this stage (the concrete has not been poured for the floor as yet). I would have to use parquet tiles or planks in the family room. My question: Regarding my patio (once deck) is there any type of wooden floor that can be accomodated ove a concrete base outdoors? We will be importing greenhart for Guyana for use elsewhere in the house – is there a solution that would utilise this or similar hardwoods? Thanks Gail Answer: Dear Gail I’m not sure I understand your question about what floor is going to be inside or outside, maybe in such a climate as yours it may not matter as long as it is sheltered from the rain. But a wooden deck is different in structure than a wooden floor. The wood in the deck can stand to get wet and because the boards are spaced 1/4″ apart they can expand a bit individually and not buckle next to the other boards. Also there is some space under the deck to allow the boards to dry out so they don’t rot. A wooden floor by it’s nature is usually a fitted tongue and grove planks,and doen’t have room for much expansion. If a wooden floor gets wet it will buckle and raise off the subfloor to make a great hump. Also a wooden plank floor will not dry properly and will soon rot. The closest to an outdoor floor I could suggest is to go a head and pour the concrete and once it has cured for about 2 months lay a framework of sleepers or screeds on the concrete. These can be 2″ by 4″ boards laid on their side made out of pressure treated wood. Then on top of this lay a decay resistant wood like ipe’. You should leave 1/4″ gaps between the boards and a 1″ space around the edge to allow moisture to escape. It would be a good idea to have drain channels in the concrete in case some rain flooded in. Ipe’ is a good decking material and is very hard and good looking, just let it age naturaly, don’t try to finish it with a varnish. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: We just had our beautiful heart pine floors redone, with with two coats of polyurethane to finish. We are seeing abundant surface scratches in one room not even a month later. Is there any product that will hide existing scratches and help prevent future ones? Keith Answer: Dear Keith I have always used at least 4 coats of poly on all my pine floor jobs. And never a lacqeur sealer as the undercoat. This may be why you have such a weak finish, just not enough film. But if they used a lacquer or shellac based sealer, you will always have a problem. If that’s the case read my article in the Floored News about Lacquer Floor Fires. So, I would say add more finish, and then be sure to read my floor maintenance article in the Floored News section. The article will suggest all the varous solutions to scratches, and the advantages and drawbacks of each. More detail than I can put in this e-mail. As always your Most humble servant, Joseph, the Wood Floor Doctor

Question: We recently bought a house which has, the owner told us, solid oak flooring downstairs. She left a special floor mop and a Polycare spray, but I have just used these (after vacuuming) on the kitchen floor and it now looks duller than the hallway, which I only vacuumed. Have I used the wrong substance or done something wrong? I misted the floor (as per the bottle instructions) and then mopped it dry again with the special mop with its cotton cover. Will the floor gradually regain its sheen or is it permanently dulled, and which product would you recommend as a polish? Thank you – I really need some help with this as I don’t want to ruin the floors! Lynda Answer: Dear Lynda Please read my floor maintenance article in the Floored News section (both parts), it should say it all. And you may try the Cleaning Center for the proper and inexpensive mops also. I mention their web site in the article. In this kitchen you are probably overdue for a re-coating, as also suggested in the article, this may be why it is so dull. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: We have oak and maple flooring. We have had a lot of moisture in our house and our floors are finally air dried, but we have huge cracks where they all meet. What can I do to seal all these cracks so moisture and air stops coming through. Marge Answer: Dear Marge There is almost nothing you can do permanently to solve this problem. Why was there a lot of moisture in the house? And what do you mean air dried, and how big are the gaps? What do you mean air coming through, I hope you have a subfloor? The filling methods I’m going to describe will work only if the wood is not loosened from the nails. You see, if I tell you that you should fill the floor with some sort of trowelable filler, then resand the floor and refinish it, all the filler in time, will crack out anyway. The best and cheapest fillers are made from lacquer finish, or polyurethane and the fine edger machine dust from maple and red oak floors. They will need to be troweled into the floor and in the case of lacquer, need overnight to dry. But the poly filler will take several more days to a week, until it is quite hard. Then, sand and finish the floor with at least 3-4 coats of oil modified polyurethane finish, and hope for the best. You will need to keep the humidity levels at 40-60% (or less depending on your climate) and from now on, avoid large (30% or more) humidity swings. The lacquer filler sticks well to the wood. But some, not all, of the polyurethane mix has been in my oak floor for 21 years now. The poly mix is very dark, may not look good on a light floor. If you want to avoid the long dry times and fumes of these before mentioned fillers, you can try the water-based filler called Pacific Filler at http://www.bonakemi.com. More expensive, but better choice of colors, than mixing your own. Most of the cheap brands sold at flooring stores haven’t enough binder to stick to the wood, so stay away from those.

Question: I have waxed wood floors from the 1750s and I don’t know how to clean them… Every product says “DO NOT USE ON WAX FLOORS.” What can I do? Linda Answer: Dear Linda This is no mystery to me, but the stores now only carry pre-finished floors, and don’t appreciate the beauty of a old waxed floors like we do. The best way to clean this floor, is of course never with water. You will need to use odorless mineral spirits. If you have little or no finish left on the floor you will not be harming it with this mild solvent. Use a white non abrasive scrub pad, while squirting the solvent on the floor. Before it dries wipe it up with lots of clean rags, until the rags are just wet with solvent, but not dirty. Let the solvent dry overnight, then apply a liquid paste wax this time. There are two brands mentioned in the maintenance article in the Floored News section of this site. And a lot more info on just how to treat floors that have a finish you cannot identify. Yes, there is a finish on that floor, wax is only a top dressing for a sound finish, and someday you might have to remove the wax and repair parts of that finish, so please read the article. You will only need to clean and wax once a year, and just do touch ups and a monthly buffing with a natural fiber (corn broom bristles) pad on an electric buffer. And of course vacuuming often, and no outside shoes should be worn on this venerable old floor. As always your Most humble servant, Joseph, the Wood Floor Doctor.

Question: Is it O.K. to staple 3/4 prefinished hardwood floors to 3/4 plywood or should it only be nailed? Answer: Dear Steven I thought I made this clear in many articles. USE NAILS ONLY FOR ALL WOOD FLOORS !!!!!! Please read my article on a nifty pneumatic floor nailer available in the search box at the top of this web page of this site, it will explain why.

Question: We have an old home, it has a linoleum floor, about 2 years ago we put those box glue on squares over it, it wore out, we have pulled some off because they’re all chipped and now there is stickiness on the original flooring, how can we get it off safely, we have six kids and can’t afford anything new so we have to deal with the old…thanks Ellen Answer: Try http://www.kleanstrip.com, they have a couple of adhesive removers that might work.