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I asked my National Gypsum rep and he said it was ok to install 1/2" Permabase to subfloor with 1 1/4" roofing nails. So we did it. Just wondering what the thoughts were on that method of installation.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Thats what it says on their website. I used to screw down hardibacker but I noted that my local tile guy uses ring shank nails, so I switched. I havent seen Permabase locally but it looks about the same as Durock?
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Tile guys here nail it down too, not with roofing nails though, they don't seam like a good choice to me. I can see the need for the large head, but I'd go with a longer shank and try to get ring shank or screw shank something for some extra holding power.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
You have to follow the printed instructions with the tile backer or the warranty will be void. I believe the nails just hold the board down until the thinset which should be under the tile backer dries. Permabase is a little bit stiffer than durock, it is lighter, it has styofoam balls in it.
A friend of mine installed it w/o thinset, he didn't think it was necessary. 2 years later spider cracks all over floor.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
It needs to set in a bed of thinset from a 1/4" notched trowel and screwed or nailed down, the thinset ISN'T there to adhere the boards, it's under there to fill any voids, the screws or nails hold it down, and screws hold better.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Ever try to remove durock when its nailed and thinsetted down? I spent more time breaking it away from the thinset than watching the screws or nails pull through the board.
Mike - I would remove it and use thinset if you still can
I like to use Ditra instead, saves me time. I can install it and tile the same day.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
It seems all the backer boards I have run across approve or even recommend roofing nails for installation. I like the big heads, but sure wish they were more substantial as far as thickness. But, like others have said, once the thinset dries, the nails are pretty much a moot issude as far as holding power.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
For the last time, thinset is NOT there to adhere the boards to the floor, they even recommend unmodified, why, so it doesn't stick, it's there to fill the voids, nothing more, screw it down, screws hold better.
Or just switch to Ditra, CBU is a waste of time on a floor unless you need the height. just my .02 worth.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Thanks for the replies!
I should have posted prior to the start of that job. But my tile guy used the 1/2" permabase with 1 1/4" roofers and no thinset between the sub and backer. The house is a rental, we work for the h/o and he really could care less since its a lease to own property with a 90 day warranty. The renters have already moved in a the tile isn't complete and no sign offs on permits. The sh@t is going to fly when I call the building inspector.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Tileman- from permabase web site-
"Underlayment: Using a 1/4" square-notched trowel, apply a setting bed of latex-Portland cement mortar (or thin-set mortar) to the subfloor or counter base. Immediately laminate PermaBase to subfloor or base leaving a 1/8" space between boards at all joints and corners. Leave a 1/4" gap along walls.
Stagger joints so that they do not line up with underlying substrate joints. Fasten PermaBase every 8" o.c. throughout board field and around all edges while setting bed mortar is still workable. Around perimeter of each board, locate fasteners 2" from corners and not less than 3/8" from the edges. Fill all joints solid with bonding material. On non-tapered joints such as butt ends, apply a 6" wide, 1/16" thick coat over the entire joint. Embed 2" fiberglass
mesh tape fully into applied bonding material; ensure that tape is centered over joint. Apply bonding material over fasteners to fully conceal. Remove all
excess bonding material and allow to cure."
I just went over the installation instructions a few weeks ago with the rep who handles permabase at the lumberyard. If you have ever tried to remove it with and without the thinset you will see how easy it is to remove when it's installed w/o thinset.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
YES, I know it's easier to remove without thinset, but I still stand by what I said, it's NOT there to adhere it to the subfloor, that's why un-modified can be used, un-modified doesn't stick very well if at all to plywood.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
TileMan,
Don't get all excited and please stop insisting that unmodified thinset under CBU's is what is recommended by the manufacturers. Because most do NOT.
As far as I know, all except two manufacturers, (Hardie and Fin Pan), even suggest to use unmodified to install their CBU, and Hardie says either one.
I believe this was started by a few concerned about how to remove a CBU floored floor in the future. Me too! Darn, I don't want to be the one that has to remove one of the floors I did this way!
I do not necessarily disagree that unmodified will work fine, but most of the manufacturers want us to use modified.
Please do not give me a speech about what the purpose of the thinset is. I know very well, and have know since the early '70's when Fin Pan introduced WonderBoard to the tile industry. Yes, I always say....the fasteners hold it down, while the thinset holds it up. ;>)
Re: 1 1/4" roofing nails to install 1/2" Permabase?
I never said you had to use unmodified, it doesn't matter to me what anyone at this point uses, lol.
Just saying the nails or screws aren't there to hold down the boards till the thinset cures and relying on it to do the job, as some have stated, the screws or nails IS what holds them down, not going to split hairs anymore on this issue, I know what every manufacturer suggests, so not going there either.
Use Ditra and you won't have to argue over CBUs on a floor, oh wait, now there's going to be a few who disagree with what thinset to use for Ditra as well.
Heck, I still mud most of my installs, haven't installed a CBU on a floor in over two years now, oh wait, that's a lie, sorry, had to raise a small entranceway up 1/4" to meet existing flooring, used it for that.
Re: 1 1/4" roofing nails to install 1/2" Permabase?
Maze makes a double hot dipped galavanized 1 1/2" ring shank nail. Use the cheapest dry set mortar you can find for under the backerboard, its not for bonding.
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