Replies

1. 
   Guest_ | Jan 17, 2000 08:51pm | #1

   *
   You can cut cement board with a razor knife. Score and snap. You'll have to clean up the rough edge. A carbide tiped scoring tool works better. For the cleanest cut use a diamond wheel in a small grinder or a masonry blade in your circular saw. The later two methods produce a lot of dust, and make sure you wear safety glasses. Yes, you do need to comb out thinset to fully adhere the cement board to the sub-floor. The fasteners you use depend on the type of installation. Wet or dry? Grout and thinset are not waterproof. The cement board screws work well, and are corrosion resistant. I use them.

   Dave

1. 
   Guest_ | Jan 18, 2000 08:06pm | #2

   *As Creature stated, a carbide tipped razor knife blade works good, but a power saw is quicker if you have a lot to cut. Fine tooth carbide blades in the saw work well, as do mason or diamond blades. They make lots of nasty dust, so wear safet goggles and dust mask.The screws HD was trying to sell you are made specifically for the cement board. They are indeed special screws, and should be used. Drywall screws will not hold up, nor will wood screws. The concrete screws have corrosion resistance, have a hardened edge on the thread pitch, and are made of better grade of metal. A thin layer of thinset is recommended, but many installers do not use it. I do because I want the product to last as long as possible, be firmly secured to the base, and because the manufacturer recommends it. Just a thought...James DuHamel

1. 
   Guest_ | Jan 19, 2000 05:36am | #3

   *Arbor Homes,

   I'm not a fan of the "motorized" method of cutting wonderboard but, I have used a jigsaw and hole saw for cutting circles with very good results. I once worked in a room next to a guy cutting this stuff with a grinder. . . the dust was incredible and there was a gray stone dust on everything in about 5 minutes. I gave him my carbide tipped cutter and my carborundium(sp) stone but, he wasn't interested, said he been doing it like this for years. I wasn't interested working in the room next to him either so I left and waited for he to complete whatever the hell he was screwing up.

   Whenever I'm installing wonberboard on top of plywood I always apply a layer of thinset with a small amount of latex additive in it. This just makes for a better job.

   Joseph FuscoView Image"Whenever, therefore, people are deceived and form opinions wide of the truth, it is clear that the error has slid into their minds through the medium of certain resemblance's to that truth." Socrates

1. 
   Guest_ | Jan 19, 2000 07:00am | #4

   *Hey Joe!Good to see ya. I been wondering what happened to ya. I sure miss reading your posts. I always learn something, and enjoy the reading.I really hate cutting the stuff with anything motorized myself. The dust tears my sinuses up! If and when I do cut it with a power saw, I do it outdoors, with a fan blowing AWAY from me. Just a thought...James DuHamel

1. 
   Guest_ | Jan 19, 2000 05:52pm | #5

   *Hi James,

   It's not to say that I myself cough. . .cough. . . haven't cut it once or twice with a grinder but, just that its much neater, clearer and quicker with a scoring knife.

   BTW, my friend with the grinder that day. . . wasn't even wearing a mask. . .

   Joseph FuscoView Image"Whenever, therefore, people are deceived and form opinions wide of the truth, it is clear that the error has slid into their minds through the medium of certain resemblance's to that truth." Socrates

2. 
   Guest_ | Jan 23, 2000 12:07pm | #6

   *I would never, ever cut tile backer with a saw or grinder. A sharp utility knife will cut a room of backer much faster than a carbide scoring knife.A common rookie mistake is to believe that it should fit tight. Joints should be at least an 1/8" open and then grouted with thinset when they are set in thinset (horizontal surfaces). Take a minute and grout the scored and snapped edge to the tub so you can grout the tile to the tub instead of caulking.joe d just my thoughts

3. 
   Guest_ | Jan 24, 2000 07:11am | #7

   * joe d,

   I'm sure you go through a "lot" of sharp blades. . .

   Joseph Fusco View Image "Whenever, therefore, people are deceived and form opinions wide of the truth, it is clear that the error has slid into their minds through the medium of certain resemblance's to that truth." Socrates

4. 
   Guest_ | Jan 24, 2000 12:44pm | #8

   *Hi Joe F.Obviously the blade stays sharp about.01 seconds. By using the sturdy old steel handled fixed blade utility knives I can press firmly enough to compensate for loss of sharpness. They do sell those blades by the hundred for a reason.joe d

5. 
   Guest_ | Jan 24, 2000 03:46pm | #10

   * Hi Joe,

   I usually use my knife to cut the back (the fiberglass) after I use the scoring tooland "snap" the board. It does save on blades though not many.

   Joseph Fusco View Image "Whenever, therefore, people are deceived and form opinions wide of the truth, it is clear that the error has slid into their minds through the medium of certain resemblance's to that truth." Socrates

2. 
   Arbor_Homes | Jan 24, 2000 03:46pm | #9

   *
   Can anyone tell me the best way to cut that stuff? As per the instructions,I tried a razer blade but it seems like that would take forever.

   Also, does anyone really put down an even layer of thinset first like they say to do? Finally, do I really need the "special screws" they less at Home Depot or can regular drywall screws by used. I figured H.D. was just trying to sell me something more expensive.

   Thanks for the help.