Unfortunately, you cannot trim the cable for this product; please measure your space first then buy according to your square footage. The only type of floor that this can be installed over is ceramic. Yes, you will need to purchase a thermostat for this unit. The thermostat can bee seen at http://www.homedepot.ca/webapp/wcs/.... Other than the thermostat which is sold separately nothing else is required. (Depending on the type of floor covering that you will installing, you can either cover the cables with a dry-set latex mortar or with polymer-modified self-leveling cement.) I hope this helps.

The first thing the heating system wil do is heat the concrete, then it will come up, insulation and thickness of the concrete is very important, if you think that there will be a big heat loss, there are some membranes that will do a heat barrier. Easy Mat ( Custom Building is the manufacture ) can be one solution, this Mat is sold at Home Depot.
If it's a room that is very cold normally, you should isolate the concrete. If it's a room that is normally not that cold maybe it can be worth it installing cable on the concrete, it will generate very nice heat.

Hope my awnser has help or you can contact our customer at 1-877-800-8783.

Hello,

The total wattage for this kit is 2084 watts.

Thank you,