[ctviggen]

I bought this tool for fixing squeaks in floors that have carpet:

http://www.acehardwareoutlet.com/html/product5106125.htm

This site recommends placing cardboard on the floor and using a stud finder to locate floor joists:

http://www.hgtv.com/hgtv/rm_floors_carpets_rugs/article/0,1797,HGTV_3709_1395774,00.html

Does this really work?  I've tried using this technique on popcorn ceilings, and it did not work.  Any other ways I can find floor joists?  Are floor joists typically 16 inches apart?

Also, what would happen if I subsequently decide to remove the carpet and add a wood floor?  Do you think I'd have to go cut off each of the screws?

[Rashiki]

Also, what would happen if I subsequently decide to remove the carpet and add a wood floor?  Do you think I'd have to go cut off each of the screws?

As long as the screws end up flush with the subfloor, you should be able to install nail-down hardwood flooring without too much trouble. When I pulled up my carpets to install hardwood I found that the carpet installer went crazy with a staplegun and nailgun when putting down the underlay. I pulled up most of the staples, but left a few flush nails/staples. In the rare case where one of my flooring nails hit an old nail and wouldn't go all the way in, I'd just put a nail next to it and pry out or break off the unsuccessful nail.

 -Rob

[honesthoff]

I don't have any first-hand knowledge of this tool but I did see Tom Silva use it on Ask This Old House a couple months ago and it looked like it worked pretty well.  I think the score on the the screw head breaks just a hair below the subfloor.

[ctviggen]

Thanks for the information!  If I can remember, I'll come back to this thread and update it with my results (good and bad).