I am Replacing ceramic tile in a small bathroom. One corner is low. –the subfloor is now ply wood, hardiebacker will go over that then the tile.
one corner (2 ft x 3 ft area) of the room is low. I Plan to use some self leveling cement.
Question- Do you put the leveling compound on top of the hardie cement board? (rather than on the subfloor itself)?
Any good brands? or are they all about the same- Lowes here sells a MApei brand- thanks
Replies
Mapei ultra is an excelent SLC, portland rather than gypsum based. Going over the hardi should work just fine.
Leveling compound goes under the Hardi if you want to preserve the bonding properties / characteristics provided by the Hardi.
Order of work would be:
Leveling compound and let dry.
Thinset, apply Hardi, nail / screw and let dry.
Tape seams (some prefer to tape as they tile).
Thinset and tile.......
Jim
seems the screws going thru the hardie would not penetrate the SLC?
The screws should go right through the SLC without much trouble.
Unless your talking a really think layer of SLC.....
I spoke to another person today and they also said to put the self leveling compound under the hardie- the reason was that the hardie would then be a smoother surface than you might get from the leveling compound.
When I did my bathroom floor it was out of level by about 1/4 inch. I put down about 1/2 inch of SLC and it was very smooth. I tiled right on the SLC. When I use SLC on wood I put down the primer first and then wire lath before the SLC. Have done three bathrooms this way and they have all held up well. I don't recall the name of the product, I just used what ever brand HD sells.
anyone who thinks the hardie makes a smoother surface than SLC does not know how to float the SLC in.
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Mix the whole bag (contents) even if you don't anticapate using it all.
Much easier than trying to figure a partial receipe.
were you able to screw thru the Hardie into the leveling compound?? Or is the leveling compound too hard
Edited 7/18/2009 4:54 pm ET by edwardh1
I think the above Q was for you
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Thanks for the heads up.
JimNever underestimate the value of a sharp pencil or good light.
Screw through the slc?
Yes, but, if push came to shove, you could bore pilots in the relatively small area you are dealing with -- 2x3 = 12-15 pilots @ 8" oc.
Impact driver - mine's a cheap Ryobi - "non-professional", but it works every day.
Jim
Never underestimate the value of a sharp pencil or good light.
Edited 7/18/2009 8:55 pm ET by JTC1
I ended up having to use a leveling compound after the Hardi was down in an area
about 3' x 8' from a feathered edge to about 3/4". I felt better using a levelling compound that I floated myself rather then the "self" levelling type. You have about 10 minutes to work with it. Read the bag and do only as much as you can handle screeding at a time. I did that area in two mixes. It does dry hard as a rock. Harder then I even imagined. It worked fine over the Hardie...but if I knew I was going to need it before hand I'd probably have done it b/4 the HArdie but either way it worked great.
I used Henry brand(in bags)(that area took 2 bags) from Home Depot. FWIW the material is much less expensive using the compound you level yourself then the self leveling which might not even be a consideration in small areas or if you're uncomfortable screeding it on your own.
I know a lot of people that had a hard time w/the self leveling type so if you go that route read the directions thoroly and be ready to do all the prep work exactly as it needs to be done so you can move quick after you mix it up..
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Just make sure you help along the leveling action of the SLC. It doesn't actually go flat unless you help it.
You have about 5 minutes working time.
Tu stultus es
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
If you had used SLC you would not need the Hardibacker. Why create that extra work for yourself? SLC is made to be a good substrate for directly bonding thinset and tile.
HD sells Custom's SLC. It is good stuff but you need to be ready to move quickly because it sets up fast.
Check out information over at John Bridge:
http://www.johnbridge.com/vbulletin/showthread.php?t=1807
See photos here beginning with post #51:
http://www.johnbridge.com/vbulletin/showthread.php?t=3710&pp=15&page=4
I highly recommend the two trash can method -- one for clean water for mixing, and the other for mixing. I mix two bags of SLC at a time in a trash can and pour. Mark a line in a clean bucket that represents the amount of water you need for two bags of SLC. Pour water in the empty trash can, dump in two bags of SLC, mix and pour. See photos of a couple of my SLC pours below.
And don't forget to use the SLC primer.
Billy
Edited 7/17/2009 8:49 pm ET by Billy
Edited 7/17/2009 8:50 pm ET by Billy
I'm impressed, but if that was all on the same job, that home must have
been a POS.
If not for POS homes there wouldn't be much work.
Old basement slabs are almost never level -- some new ones too.
Billy
>>Old basement slabs are almost never level .... <<<<
Most old basement slabs around here have at least one floor drain, level wouldn't work so well.....
JimNever underestimate the value of a sharp pencil or good light.
SLC down the drain is an expensive proposition.
I highly recommend you not use cement board over slc.
When you nail or screw the cement board through the slc and into the subfloor, you stand a great chance of the slc cracking and it'll be like walking on peanut brittle.
"crunch crunch crunch"
Thanks- a friend said to drill pilot holes. He said with the slc under the backer you got a smoother surface for the tile.
Self leveling compound works great. There are two cautions I can offer. First, if you have any holes or cracks in the floor it will run through, so they all have to be plugged. Second, the mixing ratio is critical. Don't mix by eye or guess. Measure exactly how the bag tells you to. It is beneficial to help it along. You can't just dump it in a pile in the middle of the room. A makeshift squeegee or just a hand trowel helps. Don't fuss with it. Just push it around quickly and let it do its thing.
Mix with cold water, not a bucket that's been sitting out in the sun, and keep the bag in a cool place (not a hot car) the day before.