Hi. my home is an older one. The floor has 4 x 8 beams 36" on center. Over that is 2 x 6 t&g, I think it is Douglas Fir. Currently that is overlaid with 5/8 chipboard. I will remove the chipboard but wonder what to put on top of the t&g. I am leaning towards 7/16 OSB. Do people think this would be acceptable? Also, would I have to nail the flooring perpendicular to the t&g or would it be acceptable to nail parallel to the t&g if covered with OSB? Thanks for any help.

Get the roll. Long story short- we installed floating cork 4 years ago in our basement and bought the sheets. PITA to put down and very hard to lay flat- we did it to save money. We had a flood, put down the same floor again, and used the foam underlayment that you buy in rolls. This stuff was a breeze to install. It cost more, but it wasn't really that bad in price. Saved us a lot of time, and it looked better too.

I'm assuming the cork will be UNDER the heat mats...and then the heat mats will have the hardwood OVER TOP? Cork is rated for in-floor radiant heat....but I always worry about putting electric heat mats DIRECTLY over a product that will CATCH FIRE! Yes. Electric heat mats have a long and glorious history of "shorting out" (although I must admit they are getting much much better) which can cause a spark. Cork doesn't like to burn but it CAN burn and it WILL burn if something is hot enough and allowed to sit long enough (like a sparking electrical wire sitting underneath hardwood). For that reason, I have always said that cork should be encased in concrete if heat mats are being used on top. I always err on the side of caution with fire ratings. The next thing you MUST do is to find out if the FELT material is rated for in-floor electric heat (many are not because they are made up of mixed fibres like PLASTIC = they can melt). And then, finally please check to make sure your engineered hardwoods are rated for ELECTRIC in-floor radiant heat. Many are NOT. Many ONLY ALLOWED the hydronic heating system (water/oil/gel filled tubing). I'm sorry to say but the BIGGEST problem isn't the cork or the hardwood or the felt. It is the ELECTRIC heat-mat system. More than 30% of flooring products on the market do NOT allow use with ELECTRIC heat-mat systems. The heat produced is often TOO HOT and the wires themselves are too delicate for use under many floors (delicate wires break = sparking = fire hazard). Ignore the heat-mat company's advertise. Investigate the OTHER materials used below/above the mats. I think you will be surprised what you find (or don't find...many do not allow this type of install). Personally if it were me, I would work with 1/4" cork and upgrade the wall heaters with lovely little baseboards that are efficient. The cork + new heating baseboards = wonderfully efficient. Save the $10K from the heat-mats and invest a little bit into upgrading the baseboard heaters. Cork will do the rest - both thermal and acoustic insulation all in one product. Skip the electric heat mats.

I agree. Sadly the installer's warranty will have passed. Most offer 1-2 years....if the homeowner is lucky. At this moment in time, there is nothing much for a homeowner to do. There is no recourse - other than calling them and complaining. This gets a bit odd if the homeowner purchased/specified the hardwood (was it 'nail/cleat' only?). Did the homeowner state the cork was a requirement? Did the homeowner have the option of a 'double stick' (glue the cork, let dry and then glue the hardwood) which would have doubled the cost of the labour and increase the cost of materials by $2-$3/sf? If so did they balk at the extra costs and decide against the 'best' install? Did the homeowner have any involvement in choosing the manner of install? Things get 'sticky' when it comes to today's system of homeowners picking/purchasing/specifying the materials to be used and then shopping for the installer. It bothers me greatly that cork and hardwood were improperly installed. Unfortunately it is hard to figure out where the finger should be pointed when reading 8 lines in an on-line post.