Some background info: I love in Southern California, and my house is almost 50 years old, with a concrete slab. Currently there is carpet installed. We intend to replace it with engineered hardwood.

So, on to my questions:

1) I've seen the basic moisture test -- tape down a piece of plastic to the slab, let it sit for a couple of days, and see if there's moisture. Are there any other DIY initial tests along those lines?

2) If the above shows no indication of moisture, then what's the next step? Do I need a sealant on the slab? What about a moisture barrier?

3) What if there is an indication of moisture? What's the next step, then?

4) Suggestions on the best way to check for flatness in the slab?

5) What's my better bet -- floating, or glue-down? Reasons for and against either?

6) Any other pitfalls or issues with hardwood on a slab that I should be aware of?

Thanks for any help or advice!

Bobby Joe,

1) The rubber mat test. Place a rubber mat on the concrete and wait 24 hrs. If the slab under the mat is darker, then you may have moisture issues. Warrants further testing.
2) I'd consider using a liquid moisture barrier by either Taylor, Bostick or Franklin. These are designed to work with those companies adhesives. This would only be needed if you are gluing an engineered floor directly to the concrete. If using a floating floor, you should cover the concrete slab with 6 mil polyethylene (plastic)
3) Taylor's "Lockdown" comes with a warranty. So does Franklin's system. But if you want to be 100% safe, use Taylor's "Lockdown", cover the slab with plastic, then install a floating floor over the recommended underlayment.
4) 10' straight edge; move it around and note on the slab high spots and low spots. High spots need grinding and low spots need filling.
5) Floaters are easier, faster, and if done properly, have less problems. Can have a hollow sound. Direct gluedowns will have a more solid feel but are more difficult to install, the glue is expensive, and are more prone to having problems with moisture if moisture is present.
6) If you can afford it, hire the best installer in your area. If you're going to install it yourself, buy Kahrs (a floating floor) from HARDWOODINSTALLER.COM and install that.

After doing a good bit of reading (this site is really useful!) it looks like I probably want to go with a floating floor, since I want to do it myself (my budget is tight).

A few more (probably really stupid) questions:

1) Does one remove the baseboards before starting the installation? Or is it better to leave the base moulding, and use some quarter round to finish?

2) How do you handle transitions from one room to the next when they both have hardwood? Is it necessary to use T moulding, or do you just continue the strips of wood from one room to the next?

3) For a glued T&G floating floor, what is best to use for the adhesive? Most of the installation docs I'm reading recommend stuff for glue-down but not for floating.

1) Most of the time, yes, remove the baseboards. You don't have to and can choose to use quarter round instead. Either or; your choice.
2) Some use T-moldings. I prefer to continue the flooring straight on through. I think in a very large room with a floater, one may need the T-mold transition to allow for extra expansion.
3) Not sure what you want to glue? Are you asking about which glue to use to glue a floating floor down to the concrete? Or are you asking about which glue to use to glue the floating floor together?

If you are going to float and are a DIY consider one of the glueless floaters. It will insure you get a good tight fit and you wont be cleaning glue up half the time while you are installing.

I've spent the past week going to different flooring stores, and I've decided to go with the BR-111 5/16 Santos Mahogany. I've done some reading on this forum, and I know some people don't like it that much, but I'm not looking to install something that will last a lifetime

Now, keeping in mind what I stated before (Southern California, 50 year old house on a concrete slab), assuming that there are no major moisture problems, what's my best bet for the underlayment? The literature for BR-111 floating install says '1/8" foam padding (if foam padding contains a vapor barrier backing, 8 mil polyethyline film may not be required)' + 'Moisture Barrier (recommend Stratestuff Safeguard, minimum 8 mil polyethyline film)'.

So, are there foam paddings that contain a vapor barrier backing that would be suitable that anyone can suggest? If not, where does one go to buy polyethyline film (the folks at Home Depot looked at me like I was a loony when I asked about it) and a suitable foam padding to go with it?

"recommend Stratestuff Safeguard"

It's been discontinued. BR111 no longer offers it. Any 2 in 1 foam/poly underlayment will do. BR111 does not manufacturer any type of underlayment.

Have you looked here yet?

Trim pieces and underlayment also shown here

While shopping today, I saw some 3-in-1 underlayment. What's the difference between it and 2-in-1? Is two layers of vapor barrier? Is one better than the other?

In the paint section it will be by the drop cloths and will state 6-mil poly on it, it looks like rolls of plastic.

two in one is a foam pad and a polyethelene moisture barrier laminated together , three in one has a pre taped seam all the way down one side added.