I understand the sense of caution. Callbacks are not good and can eat away at your profits. To answer your question: I have used products supplied by flooring distributors, and have included products from Ardex, Mapei and Fritztile. They were all used with an appropriate primer to facilitate bonding to what they were placed over. Additives were included to make the product less-likely to break apart and powder. I especially like Ardex SDP (Self Drying Patch)...because the PSI (pounds per square inch) rating is lower than some other products. Self leveling formulations can achieve a very high PSI and can be very difficult to nail into, even with pneumatically assisted fastening tools. When I used a product with a high PSI, I sometimes would have to drill pilot holes and manually drive in hardened spiral flooring nails. I never had a floor patch crumble. I figured...if I used a good patch, and if the substrate was well-fastened and didn't move much, I believed the installation would be OK. I believe that you have to have significant movement to get a decent patch to fall apart under a finish product. I came to wood flooring out of a family business that specialized in resilient flooring materials, so I learned a lot about what you can and cannot do regarding floor patches and their application. I will say in closing here (for general consumption) , especially for the DIYer,... if you try to use calcium carbonate patches (usually white in color...and I won't mention brands) ...you will experience quick breakdown of the product, because they are fragile and will crumble easily. If it looks like plaster of paris, it is not a suitable floor filler or patch...my opinion.

I am double posting this (from Design Dilemma) because I hope for professional flooring advice and also suggestions from people who've done this. We live in the Pacific Northwest (rainy winters and dry summers). Our house is 13 years old with ¾” OSB subfloors on joists 16” on center. We want to remove the carpeting in the dining room, living room and hallway (above grade) and downstairs hallway (on grade), and replace the carpeting with wood flooring. We also want to keep the height difference between these rooms and the adjoining tiled kitchen to a minimum. Because of this requirement, I am leaning towards 1/2" engineered wood rather than solid 3/4" wood. The new flooring would be professionally installed. Am I correct to say that OSB does not hold nails/staples as well as plywood for nail-down installation, nor does it provide a suitable surface for glue-down engineered wood flooring installation? Would glue-down installation avoid the squeeky-squeeks that might result from a nail-down installation? We have heard that installers recommend having an underlayment put down over the OSB to provide a better adhesive surface for engineered wood flooring and we would have that done. I don't think a floating floor would be an option because of the upstairs room size (50' x 15') and high ceilings (possibly too noisy). For glue-down engineered wood flooring, what underlayment would be best between the OSB subfloor and the engineered wood floor? How thick would it need to be? Thank you Mary

As above. The wide plank (anything 5" or wider is considered 'wide' by the industry) must have a 'glue assist' if you use nails/cleats/staples. That is an added expense...that's why wide plank wood floors are a serious upgrade. If you are going to use a glue-assist, then a full spread glue WITHOUT the nails is just the next step. And as G & S points out, the nailing down of thin planks (3/4" is the industry 'gold standard') could lead to more problems. And of course, being in SC you will want to make sure you have the HVAC system updated (it it needs it) to include a whole home humidistat (includes humidifier or dehumidifier or both depending on your local year round climate). Before you do anything, make sure your HVAC system has the RIGHT attachments to handle a home full of wood flooring. Traditionally that requires an upgrade....but not always (we've seen some homes that already come with the top of the line HVAC systems that have all the bells and whistles already attached).

The condo board (HOA in the USA) dictates your noise requirements. If you are using engineered hardwood you can look at a floating floor installation (to reduce costs...it's one of the reasons engineered hardwood was invented). In most of the US, I've found the requirement for noise reduction is 6mm cork (1/4"). In some of the higher priced condos the requirement is more and therefore 12mm (1/2") is required. This gets into all sorts of issues with floor heights (like through doorways, in the foyer, in the kitchen, etc). Cork is state of the art. Believe it or not, it is pound for pound dollar for dollar the most efficient noise reducer we have. It is the lowest VOC. It is the most economical and ecological of all options in the building world. Yes it is 'old school' but it is also the most viable for 95% of the population. If you want glue down hardwood in your condo, the cork will have to be glued down first. Then you have to wait for the glue to cure (24-72 hours depending on the product) and then the hardwood has to be glued down to the cork. We call this a 'double stick'. The cost of the glue, for each application = $1/sf. Just to glue down the entire thing you are adding $2/sf onto the job. Labour doubles because the glue is two layers (s/he has to glue down a floor twice). A floating engineered hardwood doesn't need any of that. The cork sheets are loose laid (no glue...just edge butted to each other) and the hardwood is floated right over top - same day. Cost of materials goes down (no glue = $2/sf savings) and the cost of labour goes down (only lays the floor once). Labour cost to install floating cork underlay = $0.50/sf. That's it. If you want state of the art, you will have to pay the price for it. You can look at mass-loaded vinyl. But vinyl and wood do NOT play nicely together. You can get some odd odours coming from the glues needed or the two products themselves will have a chemical reaction to each other and cause an odour all by themselves. You can look at the super thick QuietWalk. The acoustic numbers are very impressive but you need to work with the expensive stuff to get it up to condo standards. You can look at rubber but you are going to be spending HUGE amounts of money ($3-$4/sf) just for the low-odour product. Then the specialized glues needed to get rubber to stick to concrete AND wood = another $2-$3/sf. And you STILL risk odour coming from the rubber for decades (every time the sun hits the floor the rubber warms up and begins off-gassing faster). The 6mm cork = $0.80/sf. The 12mm cork = $1.50/sf. That sounds expensive until you compare the TOTAL cost of install (glues, labour, etc). And remember: the adhesives are the single biggest producer of VOCs in the building industry. As soon as you require a 'glue down' hardwood you are introducing glue into your home. To get away from the glue you simply float the floor. With a thick cork underneath the floating hardwood will feel just as solid as a glue down. I'm a cork flooring professional btw. I've seen your situation many times. By trying to go 'State of the Art' many homeowners discover the mess they have made for themselves. It is very sad. Personally I would loose lay the cork (over the properly prepared/flattened slab) and then float the hardwood. It is SUPER easy and achieves everything you want....while saving you close to $5/sf.