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best way to fasten backer board?

53K views 19 replies 9 participants last post by  BIG Johnson 
#1 ·
I have been reading on the different ways to fasten backer board and wondering what the pros or experienced ones on here use? For the little bit of tile i have done i have always just used my cordless drill with the special backer board screws but that is long and tiring on the knees and back. I have read that some people use a roofing nailer to fasten in down. I have a roofing gun and this would probably go alot quicker but does the nails do as good of a job as screws? Is there any problems down the road from using nails, like nails coming loose or anything? Also i have looked at the colated screw guns that you use standing up, seems good and i don't mind buying new tools but the screws seem pretty expensive compared to roofing nails. So what do the pros use to fasten backer board down? A cordless drill, corded drill, cordless impact, collated quikdrive, roofing gun?

Also i have read about using shears to cut fiber cement backer board, like these http://www.amazon.com/Snapper-PacTo...ref=sr_1_1?ie=UTF8&s=hi&qid=1231029158&sr=1-1.
Is this a good way to cut backerboard instead of using a saw blade which creates alot of dust? Thanks for any advice on these tools.
 
#2 ·
Yes, you can use roofing nails to attach the backer board (although I choose not to).
Yes, the auto-feed screw guns work...but they are expensive. I own a cordless Senco.
Yes, shears are a great (and dustless) way to cut CBU.

That said, why not just use Ditra? No screws to drive, no screw guns to buy, no need for shears. All you need is a utility knife and the proper sized trowel. DONE. Ditra is in many ways superior to CBU anyway. :yes:
 
#3 ·
nails are sometimes used but not a good way to go. Manufacturers all recommend the correct CBU screws to be used. The screws in your standup type of screwgun cannot be used. The heads must be .375" to meet requirements. These are not. Roofing nails are. Also be sure to first set the CBU with non-modified thinset. This step is never to be eliminated. Too much work to it right? This only means you should not be doing it at all!
 
#4 ·
Not sure what you mean about manufacturers all recommending correct CBU screws. When I use CBU, I normally choose HardiBacker. I've never seen them recommend only using screws. Their instructions state to use "specified nails or screws". They further define the materials as a minimum of 7/8" in length and "galvanized ring shanked underlayment flooring nails" or "galvanized or polymer-coated 18ga chisel point staples with 1/4" crown".
That said, I choose to use alkali-resistant screws. But there are other fastners that are approved too. Why are nails not a good way to go if the manufacturer approves using them?
 
#5 ·
Most, I see it is not this one do recommend the screws. I also said nails too are okay. Which ever CBU you are using to avoid the warranty follow that manufacturer's directions. Even with non-modified versus modified thinset. Wonderboard wants modified Durock wants non-modified Hardibaker I think wants modified TCA wants non modified. But the reason as I stated for the nonmodifed is the movement of the sub floor. In a bathroom, small in size it may not really matter since movement should be small to none.
 
#6 ·
Screws and nails and even staples are recommended by the various manufacturers of the backer boards.

All backers are to be set in thinset. This is not to glue the board down but to fill any voids under the boards. It is desirable in time for the backerboard to separate itself from the substrate thereby creating an isolation effect separating the tile installation from the structure. This is why "unmodified thinset" is suggested with most all products.

NOW, if this is the case - what difference does it make which fastener is used in the first place? Kinda like Burger King......Have It Your Way!:)
 
#7 ·
OK, I just asked why you made the statement, "nails are sometimes used but not a good way to go". I was curious to why not? I said I choose to use screws over nails but that's my choice. I'm not saying they're superior.
Yes, each manufacturer has their own spec's. That why people need to read instructions; perhaps one of the most over-looked aspect of the tiling procedure.
BTW, no one mentioned thinset. Where did that come from?
 
#8 ·
If I remember correctly only Util-A-Crete suggests to use unmodified under their board. (but mainly because it's cheaper). Hardie says to use either one. All the other major brands want us to use modified to install their boards. All of course recommend using modified thinset to install tiles to the boards.

The unmodified recommendation I believe comes from the TCNA and many tile setters that believe in it or do not see any down side to do so. I agree that the thinsets main purpose is to fill and support the board. This is the key to a successful installation. Technically the manufacturers' recommendations ALWAYS trumps what the TCNA recommendations.

In the past when I used to use more cement boards, (I now use Ditra as much as possible), I always went with modified for set the boards because I prefer to follow directions since I mostly used Durock and PermaBase. I always dreded having to rip out one of those installations someday though. I still haven't removed a CBU floor installed with modified, I have have no plans to ever do so. :thumbsup:

Jaz
 
#13 ·
Atlantic...I would like to use a roofing nailer cause i already have one and wouldn't need to buy anything(maybe i'll start a new thread on justifying a different new tool like shears to cut the fiber cement board!). The nails are alot cheaper than screws also. I was just worried that the nails wouldn't suck the cbu down as tight to the thinset as screws and it wouldn't fill the voids?

Is there anything you do different when nailing vs. screwing? I will use thinset and then place the hardi cbu and then nail. Just making sure the nails will embed the cbu in the thinset? You just use regular roofing nails?

Thanks for all your help
 
#14 ·
Hardibacker's instructions state to: "use specified nails or screws at a minimum of 7/8" in length; galvanized ring shanked underlayment flooring nails or galvanized/polymer-coated 18ga chisel point staples with 1/4" crown".

The length of the nail is determined by the thickness of the CBU and the underlayment/subfloor. You want the nails to just pierce the bottom of the subfloor. You do not want to sink nails into the joists.
 
#17 ·
Yes, you can obtain ring shank roof nails for roofing guns.

However, they don't need to be ring shanked if you are using an adhesive like thinset along with the installation of the boards. If you choose not to use thinset, then I'd say the best choice is the ring shanks or the screws. However, I would not suggest skipping the use of thinset.

My advice: Use thinset too.

The point is that the tacks hold the floor down tight while the thinset cures. When cured, the cement board is held solidly in place primarily by the thinset (like tile work is held in place).

For years, I only used the rock-on screws with thinset. Then one day, I was talking to my tile supplier, who also installs tile. He has been installing residential, commercial, industrial (even entire malls) for 35 years. He told me that his quickest, tried and true method on wood substrates, with zero issues, is using a roofing gun with standard galvanized roof tacks. I've done it that way since. No problems.

If you want to use ring shanks, they do cost more, go ahead. I'm not against them. I am all for a little measure of over kill, when it makes sense.
 
#18 ·
Thanks everyone i feel good about using nails now. I will be using thinset underneith no matter how i fasten it. That will be alot faster and easier than screwing and i already have a roofing gun so looks like i need to find a different tool i "have" to have!
 
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