**This is X-posted in remodeling. I failed to see the flooring forum. Apologies for the repeated info, and some difference as we went back and looked at some emails with our contract.

I have several questions embedded into my story here, and would greatly appreciate your second opinions :)

We hired a contractor to install hardwood floor and tile, and complete a few other projects in our house.

This week he did the tiling work and hit us with an additional $2200 in costs, then expected the payment the same day. I'm not opposed to paying him, but when our original entire bid was only $5000 (including some drywall, trim work, etc in other rooms), I'm taken aback by this additional cost. And the work is already complete!

Contract says "Furnish and install tile in area (approx 75-80 sq ft)- $1540." The 12x18 porcelain tile I picked out was $6 sq/ft MSRP. He said he gets a contractor discount, but I don't know how much.

So, his estimate of $1540 for 80 s/f is $19.25 per square foot tile and installation. What should I expect "furnish and install" costs to include? Even if he DID pay a full $6 s/f for my tile... he's still at $13 s/f install.

Demo fees were extra and pre-set. All has been torn out and hauled away. He found 2 small (less than 6 sq inches) areas of mold on the sub-floor and we said yes, replace it. Then he tells my husband "I need to replace the whole subfloor because its OSB and can't handle the tile." Wouldn't he have known this 3 weeks earlier when he installed the hardwood floor in the adjoining room? I knew there would be some sort of issue with the subfloor, but I was under the impression (from earlier considering this a DIY job) that most floor tiling would need a hardibacker between subfloor and tile. Is this not always true?

I was asked about joists but I honestly have no idea. House was built in 1989 if that provides any clues. ???

He also billed us for a "special tile membrane" to protect the subfloor that wasn't included in the original quote. He charged us an additional $650 for that. I assume that was materials and labor as it was 1 line item, but any pointers as to what a s/f cost on this membrane should be, outside of my calculations of $8.12 s/f? Why wouldn't a tile membrane have been included in the standard tile install cost?

So at $1540 for "Furnish and install" just under 80 sq ft is it reasonable for me to expect that this cost includes labor, tile, grout, mastic, hardibacker and/or tile membrane? The 12x18 tiles were set brick pattern, no angles or diagonals. Room is rectangular, with a doorway in middle.

In your opinion, can I negotiate on his charge for the membrane and the TWO layers of plywood? Is it typical to need a "tile membrane" that he should have mentioned in the original quote that we might need it? How about the $50 charge for "Nails" associated with the subfloor install... really!?!?!?

Also - now that the we have been in the area, we see that about 10 tiles are visibly chipped - some the size of a dime and will be under appliances, but in the main walkway there are 3 chips bigger than a half-dollar. And we have a case of extra tile in the garage, so why would they leave the chipped tile - its an obvious color difference! How hard is it to chip porcelain grade 5 tile?

Any input is greatly appreciated

Thank you! -MM