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Ok – that last message was a lenghty “yes”….
I found that snapping it works, I even bought the no-name brand scoring tool – same basic tip, repalaceable, just didn’t get endorsed. Works fine.
But I’m a saw kinda guy. and if you notice my nickname, dust isn’t a big bother… I used my 18v DeWalt circle saw to make most of my cuts. I use that beauty all over. Any cuts that require a less than accurate rip, on plywood, osb, hardibacker. Heck, it’s a tool! I also don’t rely real heavily on manual screwdrivers… if the dust is extremly bothersome on this, wait til you start mixing mortar! Not to mention cutting tiles, which is very messy. Best of luck on your project.
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I have found hardibacker scores and snaps pretty easily. If I have a narrow piece or a stubborn piece, I lay the sheet on the floor/ground, place a 2x under one side of the score mark, and walk up and down the score until it snaps.
If it still gives me trouble, I'll use a wooden block and a hammer and tap it a few times, then walk again. If it STILL refuses to break, I coax it with a wide cold chisel & a mallet.
If you must saw, use a variable speed sawzall. Don't cloud your house up using a circular saw! And don't even THINK about a rotozip!
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OK, thanks for the tips. I'll be at it again this weekend.
Sawdust...it's not really the dust...it's the smell that lingers in the house for a long time. That burnt smell. I took the last pieces outside, which is OK if it's not raining (this is Oregon). At least the concrete and mortar dust settles pretty quickly and doesn't stink. And the dust from the wetsaw with tiles is almost non-existent.
I think I'll try the walking up and down the joint technique...and the cold chisel. And I'll switch to the sawzall. Cuz I know this sucker ain't gonna snap like I want it to.
Thanks. I'll let you know how it goes (if anyone's interested).
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Rufus,
I think you may have given a vital clue as to why the Hardibacker is not snapping well: moisture content?? I grew up in Oregon, and recall it always being damp, and the humidity was high even indoors. Is this possibly the case? I live in Alaska now, and the winter air here is very dry (mainly when I do indoor work) - so products like the hardibacker snap easily.
I didn't notice the "burned" smell from the Hardibacker, but we are all sensitive to different things, so if the smell or dust irritate you, best not to do it. As to the amount of dust - my sawzall and my circular saw produced the same amount of dust. Guess I'm just used to it. But I like the smoother cut with the circular saw. Anyway, good luck with getting it all set. Don't forget to mortar below the board. Looking forward to the update!
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Sawdust,
I was wondering about the moisture content. It seemed kind of damp. But it's been sitting on the heated floor all week, and maybe it's sufficiently dry now.
Uh oh! What do you mean to mortar below the board? Mortar the subfloor before laying the hardibacker? I've heard of that but also heard it was overkill. I believe hardibacker itself just recommends nailing (roofing nails) or screwing it to the floor. Has this proven to be inadequate? Why? That board isn't gonna move with nails/screws every 6 inches all over it.
*Sawdust, Rob, and Joe,I think the moisture content was the biggest problem. It was A LOT easier to cut this weekend after it lay all week on the heated floor. Most cuts were still ragged...often giving a shiplap type edge, with the cut smooth and vertical where I scored it and undercutting after about 1/4" through. But it was tolerable. I had to make only 6-10 scores...not doing it half way through like before. I could break it by stamping on the one side while standing on the other. No other people were needed. Lesson: don't try to cut Hardibacker in Oregon in the winter. Or in Louisiana in the summer.After this experience, cutting the 1/4" stuff for the shower walls ought to be a snap (pun intended).Thanks for your help!
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Both the Hardibacker panel and the special Hardibacker scoring tool claim you can score it a few times (3 according to the scoring tool) and snap it like you do with glass or sheetrock. This has NEVER worked for me, regardless of whether it's 1/4" or 1/2". I even bought the special scoring tool because it wouldn't work with a utility knife. If I really try to force it, it breaks somewhere else. If I'm lucky, it breaks along the scoreline but it's very uneven and has to be trimmed. I can score it 20 times, and it still won't break on the line.
I've taken to using a masonry blade on the circular saw...very dusty and smelly. I've even cut it half way through (on 1/2" thickness), and it STILL will not snap. I've tried scoring both sides. No go.
Can any of you really get this to work the way Hardibacker says it will? Thanks for your ideas.
*Dear Rufus,I installed 45 sheets of Hardibacker as a base for tiles I set in my house. I scored and snapped nearly every cut and the snapped edges came out quite well.The method I used was to use the scoring tool to score the Hardibacker several times along the line I wanted to snap, using a metal or strong wood straight edge to ensure a nice straight line. I applied a firm and steady pressure with each stroke of the scoring tool to cut 1/4 to 1/3 of the way into the Hardibacker, uniformly along the lenght of the score. Using a piece of plywood (3/4"), or other wood with a good sharp edge, on the back side of the score (about 1/4 to 1/2 inch back from where the score will break) and a knee on the front side, the Hardibacker broke perfectly every time (make sure your knee is over the backer board). Now, since the the scoring tool has a beveled cutting edge, the break at the score will also have this bevel in the end. One thing I should mention is that the wood I used on the back side has to extend beyond the ends of the cut you want to make, or the Hardibacker will break at the edge of the backer board.I found that I could consistantly get within 1/8" +/- of where I wanted the final, installed Hardibacker edge to be (if I had to get that close). If I had more precise or intricate cuts to make, I used a hacksaw, jig saw, or even a carbide, or regular drill bit to assist with the cut. I used fiberglass tape and thinset mortar to tape all my joints prior to tiling. You don't need to be super accurate with the Hardibacker cuts, as the final tile (or whatever) can be cut precisely enough to fit up to a wall or fixture.In cases where I had a narrow piece of Hardibacker to snap off, depending on how narrow the piece, I would always use my sharp edge backer plywood and firm, even pressure from my knee on the front side (you could put your knee on a plywood or other strip on the front) and either my palm, fingers, or block to break off the narrow piece. In cases where that method would not work, I used pliers to grip the narrow piece and break off short pieces along the length of the score line (this could leave a jagged edge). Also, nothing says that if your score line is not deep enough, you can't score it some more after finding the material won't break as you would like.The bottom line for me: I almost never resorted to saw cutting due to the amount of mess it creates and the number of cuts I had to make. Scoring and snapping was faster and neater for me. I carefully and patiently applied the above method and adjusted as required when I found some things that worked better or worse than expected. I found that for narrower pieces and scores, I almost always needed the knee pressure on the front side to ensure a good snap. The front side pressure should also extend over the length of the cut. I will use and install Hardibacker again.
*Joe,Thanks for the description. You describe almost exactly the technique I've tried. I've found it will work fairly well with the 1/4" stuff but not the 1/2" stuff. The technique is almost identical to cutting large sheets of glass, and I've done stained glass for 30 years. I score the glass or hardibacker (except you score only once for glass), and set the piece on a flat surface with one side of the score hanging over the edge. For my latest attempt, I had a pile of about 5 pieces of hardibacker, and I was cutting the sixth piece atop this pile. I was cutting the full 3 feet width, so the score was 3 feet straight. I use a 4 foot level to get a straight edge. So I set the score just over the edge of the pile (about 1/2" away). Kneeing didn't work. Even having another person stand on one half while I stood on the other half didn't snap it. Even jumping up and down on teh overhanging piece did nothing. I kept scoring it deeper and deeper until finally it snapped, but the unscored part of the cut was jagged and stuck out 1/4 to 1/2 inch. When I had to cut off a 3/4" strip, I just used the saw, because I knew from glass cutting and sheetrock cutting how hard that would be. Skinny cuts are next to impossible to snap in glass, and you have to end up "nibbling" like you described doing with the hardibacker. I haven't tried nibbling hardibacker.I don't understand what I'm doing wrong. I can't believe the pros have this much trouble. Do you have to be pretty strong to break the 1/2" stuff? I would think my weight (140) would be enough to break it. Maybe when I try to put pressure on the front side (the scored side), I should try your suggestion of putting a strip of plywood on it to possibly distribute the force. Can't think of what else to try.Thanks again.
*Ok - that last message was a lenghty "yes".... I found that snapping it works, I even bought the no-name brand scoring tool - same basic tip, repalaceable, just didn't get endorsed. Works fine. But I'm a saw kinda guy. and if you notice my nickname, dust isn't a big bother... I used my 18v DeWalt circle saw to make most of my cuts. I use that beauty all over. Any cuts that require a less than accurate rip, on plywood, osb, hardibacker. Heck, it's a tool! I also don't rely real heavily on manual screwdrivers... if the dust is extremly bothersome on this, wait til you start mixing mortar! Not to mention cutting tiles, which is very messy. Best of luck on your project.