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ScottM
03-01-2007, 09:54 PM
Harry Dunbar sent me over here. His forum is excellent, but this one is a little closer to home. I live in the Houston, TX area and I've never installed tile in my life. It looked pretty easy when I first thought to do this project, but now that I'm getting into the details, it's getting a bit intimidating. I plan to install 13x13 and 18x18 porcelain tile over a concrete slab (more than ten years old). So far I don't see any cracks in the slab, but I've only pulled up 32 sq ft of vinyl so far in a bathroom. But being a paranoid type of person, I thought installing Ditra would be a good idea. We plan to stay in this house for a while, so I want to do a good job that will last. However, when I went out to buy some Ditra, either the dealer had never heard of it (Home Depot for one, even though they display it in their store), or was told I don't need it ("it's overkill"). Some dealers even said that unless I have a wood floor, I don't need Ditra. So, my question to the more experienced folks here is: is Ditra a good idea to make the installation "bullet-proof", or is it something I don't really need in my situation here in Houston?

My wife wants this project to get going soon. So my alternative is to just use flexbond and get going. Home Depot pushes versabond pretty hard, but my take form this forum is that flexbond is better. Anys thoughts on that?

Thanks to all for all the great advice I've seen so far.

Scott

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Marge
03-01-2007, 10:12 PM
Scott, it's late, so bear with us in getting someone over here to help you. And welcome to the forum. Glad you are here and hope we can help!

tilerik
03-01-2007, 10:36 PM
Hey Scott, although I'm no expert on Ditra, I use it a lot and think it's definately not overkill. Here is why; Concrete can shift and crack at any time, through movement or settling. The ditra acts as a crack isolation membrane so it will prevent the tile from cracking with the concrete. It also acts as a moisture barrier, releasing moisture through the groves out to the sides (another reason to leave a space around the outside). Just remember to use the recommended thin-set. I think in your case versabond underneath the ditra and an unmodified between the porcelin tile and the ditra. Maybe some others will chime in if I'm wrong but I think that is OK as long as the concrete absorbs the moisture from the thin-set. A moisture test will answer that ?.

Jason_Butler
03-01-2007, 10:47 PM
I'm not surprised HD doesn't know about. They don't carry it here in Austin.

Overkill? maybe but only time would tell. If you can stomach the extra money and a little extra labor it will definitely be cheap insurance.

From an installer's standpoint, I would only try to sell it if the slab had alot of cracks. If I only saw a few cracks( as is typical) I would use Redgard instead and save the money and labor. Keep in mind that neither will address vertical slab movement.

Actually, if I saw alot of crack I'd sell 'em carpet or laminate :)

Jason

sandbagger
03-01-2007, 10:52 PM
hi Scott - just a DIYer here who just finished a little Ditra on an older slab. Here's what I learned.

buy yur Ditra from Dave at Tile-Experts. Best price, fast delivery, and you can even call him for questions if you can't get answers here. Homer's price is high and he makes up for it by forcing you to buy more than you need. :tongue:

for slab Schluter says unmodified on both sides. Lots of folks here use Versabond successfully. Don't use anything more modified than Versabond. I used Kerabond (unmodified) and really liked working with it. Make sure you get the gray for under the Ditra. White blends with the fleece and makes it hard to check coverage.

Ditra or no, you should definitely do the water test on the concrete before starting.

ScottM
03-02-2007, 12:03 PM
I guess my frustration comes from knowing Ditra is a good product (from listening to all you guys), yet the dealers on my side of town (Clear Lake area of Houston) are falling all over themselves telling me I don't need it (and don't seem to want to sell it to me). I'd like to hear from some folks who have done tile jobs in the Houston area. Am I crazy to want to install Ditra on a good concrete slab in Houston? These local dealers seem to think so!

Scott

ScottM
03-04-2007, 05:57 PM
Sorry to start a new thread, but this is a totally different question. Does anyone have a specific method for checking level on a concrete slab? I'm having trouble with this, determining where the low spots are. It seems to me that it is highly dependent on the reference point where you started. It can't be this difficult, can it? I just need some very specific instructions on how to do this.

I'm installing 13x13 porcelain tile in a 32 sq ft bathroom. Yesterday I poured some SLC, but I think I made the problem even worse. After this project, I plan to install 18x18 porcelain in a kitchen.

How level does the slab have to be for these tiles? I've read 1/8 inch over ten feet, but that seems pretty tight of a spec. Thanks.

Scott

John Bridge
03-04-2007, 06:21 PM
Hi Scott, :)

You're not really concerned with whether the floor is level. All you need is a floor that's relatively flat. You can determine flatness with a long straightedge, something like an eight-foot 2x4 will work. :)

opiethetileman
03-04-2007, 06:30 PM
becareful with a 2x4 alot of them have whoopy de doos in them. i would opp for a peice if 1x4 in the select pint isle its like 4 bucks but its alot better than a 2x4.. But JOhn is rite the key to a floor is FLAT not always level.

MudMaker
03-04-2007, 06:53 PM
Howdy Scott,

Sorry to start a new thread, but this is a totally different question.
But it's the same project so's the info on the other thread is pertinent to all your discussions..

Yesterday I poured some SLC,

How much out of flat is your floor? Did you do the straight edge test like John n Dan suggested?
A 4' level should work for the width and can tell you a little about the long run too... If you're lookin at 1/8 " over the length it should be no problem..
Try to describe the topography of the floor...

I've read 1/8 inch over ten feet, but that seems pretty tight of a spec.

You'll appreciate the tight spec while you're setting... :yeah:

When you go to the 18"x18", it will be a little more important.... ;)

muskymike
03-04-2007, 08:08 PM
Hi Scott, I merged your thread with this one you started. We like to keep all the questions for the same project on the same thread so others can follow it. Just save this to your favorites reply on it and it will go to the top of the page. :)

ScottM
03-04-2007, 10:05 PM
Thanks guys, for all the advice.

I do have a 48 inch box level that I have been using. There does appear to be areas on the floor that dip more than 1/8 inch. The room is 5' by 8', with a 19" by 4' vanity taking up one corner.

At this point, since it is such a small area, I'm thinking of pouring LevelQuik RS over the whole area. Good idea or bad? I already made two spot pours and I think I made things worse. I've never used SLC before. I think I goofed and poured it on a high spot. But wouldn't it have just run off?

Scott

George K
03-04-2007, 10:33 PM
Scott

To check the surface's topography I used a water level, a 50' length of clear plastic tubing filled with water and a little food coloring. The length can be adjusted for the size of the area being measured. Tape one open end, along with a short ruler, at eye height,to a 6' piece of conduit. Tape the other open end to a column somewhere, or a wall, at a height of about 6'. Place both ends next to each other, with the conduit resting on the floor, and take a reading on the ruler of the height of the two equal water columns. You can add or subtract water to some convenient measuring point on the ruler.This is your reference point. It can be located anywhere on the floor. Get a piece of graph paper and move the end with the ruler taped to the conduit around the floor, taking reading every foot or so. Keep the conduit vertical and one end resting on the floor for each reading. The more readings you take, the better the picture. My ruler was calibrated in tenths of an inch. Each square on my graph paper represented one square foot. I would just write a single digit in the particular square foot that I was measuring, I.E., 2 for 0.2", 3 for 0.3", ect. I then colored all my 2's red, my 3's orange, my 4's yellow, ect. and also counted up the number of squares associated with each number. The number with the largest number of squares associated with it would be the mean height of the surface. This will give you a very accurate visual topography of that slab.

George

ScottM
03-05-2007, 10:15 PM
Should I just use LevelQuik RS over the whole area to assure it's flat? Does anybody have experience with this product? Can I use LevelQuik over the other smaller spots where I poured a one-part SLC already, or will there be bonding problems there?

Can I tile right over the SLC after it has hardened? Custom's instructions say you can tile after 4 hours. But isn't LevelQuik a portland cement that needs 28 days to cure?

I really need some expert advice here, guys, as I feel I'm in over my head right now. Thanks.

Scott

GHR
03-06-2007, 12:31 AM
I've used a quicklevel product only once and it was rock hard in only a few minutes. Cement doesn't need air to cure so it can still do that under the tile.
If it says 4 hours on the package it's likely correct.

Trask
03-06-2007, 01:46 AM
Scott, Levelquick is fomulated to cure very rapidly. You can tile on it the same day in most cases..especially with the RS. It works well to spot fix areas too. Follow the direction closely..and read up on it in the Liberry here on the site.

I would go with Ditra. I can't remember the last slab I direct bonded tile to. Concrete is a complex substrance..far from static and far from being the "ideal" substraight so many think it is. I use Customs Versa-bond under the Ditra and on top of it...But that's technically breaking the rules..and possibly the warranty. Personally I've put down thousands of feet that way and I'm not worried about it..But if you wanna do it by the book use a quality un-modifed thinset. Mapei Kera-Bond is my first choice.

ScottM
03-06-2007, 10:18 AM
Thanks, Trask, for the advice. That is very helpful.

I'm not really concerned about tiling in a hurry. But I just thought concrete needed 28 days to cure before you could tile on it. I guess SLC doesn't work that way?

More to the point, though, should I use SLC over the entire 5' by 8' area? The how-to books I've read seem to indicate to do only spot areas. But the Liberry example shows a whole area being poured, like I'm talking about. I would think you have a better chance of achieving a flat substrate if you covered the whole area. I'm just not sure what to do? :confused:

Scott

ScottM
03-06-2007, 07:58 PM
I understand there is a gentleman that goes by the name of flatfloor, an expert in leveling floors. Maybe he can help me out? Unfortunately, the main heading of my thread is mis-named, so he is probably missing my posts. Right now this is how I feel: :bang:

Scott

Trask
03-07-2007, 12:46 AM
Scott I :clap2: can get him

Mike2
03-07-2007, 11:36 AM
Scott, Jim (flatfloor) has been notified of your post here. He'll get the message as soon as he logs on.

In the meantime, if you want to change the tile of your Thread, just post it up here and any moderator can do that. And we are more than willing to do that numerous times as is sometimes desirable over the life of a project.

:)

flatfloor
03-07-2007, 09:34 PM
HiHo :)

A small area like that might be easier to just patch it with thinset depending on the topography of your floor. Get some numbers and we can advise you.

There is a whole section in the Liberry on SLCS. Levelquik is the product most commonly used.

BTW, did you use a primer? Yes you can go over the previous SLC pour in 4 hours but you must reprime. SLCs cure differently than concrete.

ScottM
03-07-2007, 11:34 PM
Jim, thanks so much. The floor definitely has some changes in flatness of more than 1/8 inch. The topography is hard to describe, as it has no definite pattern. Just some variations here and there. It is a typical slab foundation, built in Houston within the last 15 years. It had vinyl on it before this project.

I tried to fix two areas with a one part SLC called levelPlus made by Tile Perfect that I got at Homer's. Instructions said not to use primer, but to wet the area first, which I did. A poor choice? I figured it would be easier to use than LevelQuik. I think I made the situation worse, and now if I place a tile in certain spots, it will definitely pivot. I'm afraid this will lead to cracked tiles and grout down the line.

So what should I do now? Cover the whole area with LevelQuik SLC? Will there be a problem with the LevelQuik bonding to the SLC that is already down?

If I do the whole floor, will one bag do it, assuming a thickness of no more than 1/4 inch? Can you mix a whole 50 lb bag in a single 5 gallon bucket, or do you want to divide the mixture into several buckets?

Thanks again for the help and advice.

Scott

Mike2
03-08-2007, 12:02 AM
Scott, try smacking that LevelPlus real hard with a hammer. Can you bust it out of there? If so, do it and loose it.

LevelPlus is not SLC. It's a pre-mixed liquid self leveling goo inna bucket that I for one would not trust...at all under my tile. Made by the same company that brought us Stand’n Seal, “Spray-On” grout sealer, another looser.

:)

tryanythingonce
03-08-2007, 03:39 AM
Scott; another option I have had success with is to pour a small amount of water on the floor where you think the low spots are, deep enough that the water settles into the low spots. If you aren't sure you can water down the entire floor and put a fan on the floor and let the water evaporate some. Water always seeks it's own level so within a few hours you can see where the low spots are.
Then take a grease pencil and trace around the "puddles". This is a great way of giving you a "roadmap" of where the low spots are. Pour your SLC into these areas and feather trowel them out around the edges so it's fairly smooth. Once you get them close put Ditra over this and you should be fairly flat.

Paul Denison
03-08-2007, 08:36 AM
That water idea is fantastic! I'm going to try that this weekend.

ScottM
03-08-2007, 02:15 PM
Oops. Looks like I made the first big mistake on this project.

I did try smacking the LevelPlus with a hammer. It just dented it where the hammer hit. But then I tried using a chisel, and chunks came right out. Should I just chisel it all out? I had no idea levelPlus was not a good product.

Scott

Paul Denison
03-08-2007, 03:01 PM
Now that you have a hole, get the chisel or pry bar under it and take it all up.

flatfloor
03-08-2007, 04:41 PM
I'm confused do you also have LevelQuik on the floor?

ScottM
03-08-2007, 07:06 PM
Sorry to confuse you, Jim.

No, there is no LevelQuik on the floor. Just a couple blobs of LevelPlus that I poured this past weekend. I was not able to bust it out with hammer blows, but did manage to pull some chunks up with a chisel. Where do I go from here?

Scott

ScottM
03-08-2007, 10:53 PM
This stuff is coming up easily in large flakes, like old paint chips. And the flakes are slightly pliable, sort of like plastic. This material didn't bond at all to the concrete slab surface. Would this have been a problem down the line had I tiled over it? Does a real SLC like LevelQuik perform like this too? I wouldn't think so.

Scott

flatfloor
03-09-2007, 11:50 AM
Would this have been a problem down the line had I tiled over it?
Yes

Does a real SLC like LevelQuik perform like this too? I wouldn't think so.
No
:)

ScottM
03-09-2007, 04:35 PM
Jim, you are a man of few words. I appreciate your response.

So, back to my question from a few posts back. Should I use LevelQuik over the whole 5'x8' area to ensure good flatness? I'll chip up all the levelPlus junk up today or tomorrow. There are some spots that are more than 1/8" out of flat over the floor, but it does not follow any particular pattern.

I'm told by a few folks in town that I don't need to worry about flatness. Just use more thinset under the tile in these areas, I'm told. These folks are not professionals, and I don't think that advice sounds right to me. I wanted to hear what you all have to say. Thanks again.

Scott

flatfloor
03-09-2007, 07:04 PM
Scott, it's Friday, are you done? :D

If you're sure you're out no more than a 1/4" just go with the thinset.

Be sure to get all of the other goop off, maybe a wire brush and a vacuuming.

Happy tiling. Remember we love pichers. :)

ScottM
03-11-2007, 06:13 PM
OK, I got up all the fake SLC goop. Then I tried tryanythingonce's idea of pouring water on the slab to find the low spots. Using an angle grinder, I knocked down a few high areas and the floor is pretty flat now. However, in the process of using the water, I noticed something. The water was not soaking in very rapidly. In fact, it took hours to soak in (or evaporated). Does this mean there is sealer over the slab? The only flooring that has been on this slab was vinyl, and I got up all that glue. I assume thinset will have a problem bonding to this surface? :crap:

If so, what to do about it? I really don't want to deal with a scarifier. Homer's book says you can use TSP to clean the surface. Does anyone recommend this? Or will I have to grind the surface down?

Thanks again for all the help.

Scott

ScottM
03-12-2007, 07:31 AM
Anyone?

Scott

ddmoit
03-12-2007, 07:48 AM
Scott,

I believe the test for absorbency usually involves a few sprinkles of water and then watching to see if the droplets soak in. I think you may have had too much water on the floor to determine proper absorbency. Is any of the concrete dry now? If so, hit it with a few drops of water and see what happens. I bet you're fine.

cx
03-12-2007, 08:12 AM
Homer's book says you can use TSP to clean the surface. Does anyone recommend this? Yep, I do. Now try to get Homer to actually sell you some TSP. Another thing our benevolent fathers in Washington are saving us from. :crap:

They'll have TSP "Substitute," but no TSP. And having tried it on a very sound but dirty slab not long ago, I can tell you it ain't the same thing at all.

Anybody know if a fella can buy the real thing anywhere any more?

GHR
03-12-2007, 11:31 AM
I searched google for "trisodium phosphate" and found on wikipedia, a link to this company:

http://www.savogran.com/Retail_Products/Cleaning_Products/cleaning_products.html

Seems to be the real deal too.

Why are they limiting TSP? Because it could be used as a weapon from being a fertilizer?

Paul Denison
03-12-2007, 04:48 PM
Last year I got some at K-mart.

cx
03-12-2007, 05:39 PM
Yeah, they show a powdered form on that site, Henry, but to buy it you gotta "see your local Savogran retailer." Well, I ain't got no eye-dee who that is, but I'm willing to bet when I got there they'll have everything available but the real thing. Can't prove that, of course.

And I've never used it in a powdered form, always liquid.

But thanks for the link. :)

And I ain't sure we even got us no steenkin' K-marts any more, Paul. :D

Dead Sam Walton's place had the same ol' "substitute" as Homer when I looked there (damn, but I hate goin' into those places).

But I'm sure it's for my own good. :rolleyes:

ScottM
03-12-2007, 09:14 PM
OK, I found some TSP at Lowe's, but it is the powered kind, made by DAP. I assumed it was the real thing, because right next to it on the shelf was "TSP Substitute", also in powered form from DAP. Am I assuming wrong? Is the powered form not the real deal? Homer's did have a liquid called something like Phosphoric cleaner, but it did not say it was TSP.

I tried cleaning a small portion of the floor with the stuff from Lowe's, and nothing dramatic happened. I guess I expected the phosphor to react somewhat with the concrete, I don't know. CX, what has been your experience with TSP?

Dan, I tried the absorbency test using only a few drops. The water did appear to absorb in, but it took anywhere from 30 to 45 minutes to totally absorb in. Humidity is pretty high here (Houston), so I don't think it just evaporated. Think I got a problem?

Scott

ScottM
03-19-2007, 07:16 PM
Well, no one responded to my last post. I have been out of town and have not been able to get back to this project. If anybody has any words, I'd sure appreciate it.

I have another question concerning installing Ditra. The Schluter handbook and several folks here say to use a wooden float to press the membrane in after spreading the thinset and rolling the Ditra out. A tiling book I have by Tom and Lane Meehan (apologies to Mr. Bridge) says he uses a 75 lb linoleum roller. I would think this technique is a heck of a lot easier than using a wooden float. Has anybody else tried the roller?

Of course, I've got to find one of those rollers...

Scott

Dave Gobis
03-19-2007, 07:21 PM
if it takes more than 5-10 min. for the water to go in, you have a problem. Roller or trowel, matter of preference and availability.

cx
03-19-2007, 09:55 PM
My experience with real TSP is just that it does a real good job of cleaning. Doesn't do anything magic, but it certainly works better than the new TSP "Substitute." :(

Big ol' roller might be fun, but I sure don't think you'll find it actually necessary if you apply your thinset properly.

My opinion; worth price charged.

ScottM
03-27-2007, 09:59 PM
I got back on this project this evening. Attempted to install the Ditra and it was a disaster! :mad: There is no way Schluter's recommendation to use a 1/4 x 3/16 v-notch trowel can be right! I only put down enough thinset to bond down about 3 feet of an 8 feet long piece of Ditra. I then pressed it down with a wooden float and took a look at the coverage. (I'm using unmodified Kerabond, so I can see the gray underneath.) I'd say there was only about 50% coverage. I went over it again with the float, but it didn't help. So I pulled it up.

Questions:

1. I cleaned up the 3 feet section of Ditra as best I could, but it still has a coat of thinset on it. Will this be a problem, or will I have to cut this section off and throw it away. This stuff is too expensive to waste!

2. I scrapped up as much thinset as I could from the slab, but there is still a skim coat there. Will this be a bond breaker?

3. In the real world (not Schluter's world), what type and size trowel would one use to lay down Ditra? I just read in John's book (which, coincidentally, showed up in my mailbox after this disaster) where he says he uses a 1/4 x 1/4 square notch trowel to lay down Ditra. Has anybody else had experience with this?

I really appreciate the help here. Thanks again.

Scott

cx
03-27-2007, 10:23 PM
Take that Ditra outside and hose it down real well, Scott. It should be OK to re-use.

When we got to play with alla trowels in the world at Schluter school, my favorite for Ditra was the 1/8x1/8x1/8 square notch, which I ain't seen another one of since. :rolleyes:

As I recall, the 1/4x1/4 vee notch did fine, but people complained about the 3/16x3/16 vee notch. Many sleeps since then.

Don't recall if I tried the 1/4x1/4x1/4 square notch at all, but I know I find it way too big for Kerdi, which should be very similar. I think a fella could use that trowel successfully if he laid it over pretty significantly, but let ol' JB tell you how he does it. :)

My opinion; worth price charged.

ScottM
03-28-2007, 07:57 PM
Sorry to bump this, but CX didn't entirely answer my question (God luv 'em!).

Does anybody have a solid recommendation on a type and size of trowel to use for installing Ditra. No way does Schluter's recommendation work.

Also, some advice, please, on mixing Kerabond thinset. I only need a couple of gallons at a time. How many parts water and parts powder? Mapei just tells you how to mix a whole 25 or 50 lb bag! No way I need that much.

Scott

01floor
03-28-2007, 10:06 PM
I think we may be over thinking this a little scott but that has never killed anyone. I have been using ditra since it showed up here in Austin and I use a 1/4x1/4x1/4 square notched trowel. I do not want to contradict Dave Gobis as he is one of the most knowledgeable people on the web when it comes to tile but I was told by the ditra rep not to roll for fear of crushing the cones. The squares. You also have to mix the thinset a little looser than what you would use for tiling.

I like my thinset to fall off the paddle in 3 seconds, not flow off. Just a little stiffer when you laying over the top of the ditra. It is also best to start with the flat side of your trowel and work it into the squares and than rake it with the teeth. Hope that makes sense.

I use rubber grout floats to set the ditra into the thinset and I look at the ditra from the top and you can see it change colors when the thinset sets into the scrim felt. This requires some elbow grease for sure.

As for Houston considering half of Houston is a swamp You are doing a good thing with the ditra. I recommend that you set the ditra one day and let it cure and then lay the tile. If you lay tile on wet ditra and have to pop up a tile you will break the bond and that is not a good thing. Do not fill in the squares until laying tile or you will create a cold joint/bond. Hope this helps some and good luck. :goodluck: :goodluck:

:jacked: :jacked:
had to do the above avatar as I think it is cute as a button.

Dave Gobis
03-29-2007, 04:52 AM
Don't worry about contradicting me,your right. They prefer not to roll for that reason, however if you do, the maximum weight is 75#, and they prefer 50#. We host Schluter classes, and they have Schluter rollers but rarely use them. For trowels they use either 3/16 or 1/4 V notch, 1/4 square works too but new guys tend to get too much thinset under the sheet and make it lumpy.

ScottM
03-29-2007, 03:22 PM
Thanks, guys. I think I'll go with the 1/4" v-notch, as it sounds like I'll have less problems with that.

Any specific instructions on the thinset mixing? I have about 30 - 40 sq ft of Ditra to lay down. I figure about a 2 gallon bucket full of thinset will do it. But how do you figure how much water to start out with? I'm using Kerabond thinset.

Scott

ScottM
03-29-2007, 10:01 PM
No one?

01floor
03-29-2007, 11:02 PM
2 quarts

cx
03-30-2007, 07:18 AM
Scott, the instructions on the bag are gonna give you an idea of coverage for various applications (not yours specifically, of course) and will give you a quantity of water to mix with an entire bag of thinset. You'll hafta do the math for each smaller batch you want to mix.

Put about two-thirds or three-quarters of that water in the bucket and start mixing in the measured amount of thinset. Add the remaining water when you see that the mix requires it.

Once you have made a couple batches at the manufacturer's designed mix-water ratio, you'll have a good feel for how much more or less water it takes to get the consistency you want for the particular application.

Keep in mind that a little water makes a lot of difference once you are at or near the design ratio.

Some things you just hafta get some feel for. This is one of'em. :shades:

My opinion; worth price charged.

ScottM
03-30-2007, 12:09 PM
CX, thank you again for the great advice. I was starting to get the feeling I had hit a nerve here, and that this was a subject where the pros don't like to give out their secrets. :lol2:

So just so I'm clear: Mapei says for a 50 lb bag of Kerabond, use 6 qts of water. For a 25 lb bag (have not seen one of those :shrug: ), use 3 qts. As 01floor said above, use 2 qts. That would mean about 17 lbs of powder. Based on your very excellent instructions above, it seems that you would actually weigh out this amount. That right? Somewhere I got the impression (from JB's book?) that one just puts some water in the bucket and starts mixing in the powder until it looks like a good mixture. That's fine for a pro, but not so good for a DIYer.

Be aware that I'm an engineer by schooling and tend to overthink things and need specific instructions to feel comfortable!

Scott

cx
03-30-2007, 12:29 PM
Somewhere I got the impression (from JB's book?) that one just puts some water in the bucket and starts mixing in the powder until it looks like a good mixture.That's precisely how most of'em do it most of the time. :)

The very best way to determine what the manufacturer has in mind is to mix a full bag, or very carefully measured part of a bag (not less than half a bag for the test would be my recommendation) with exactly the amount of water specified on the bag. And mix it at exactly the speed range given, for exactly the time specified. Let it slake for exactly the specified period, and re-mix exactly as instructed.

That, theoretically, is how the pookey is designed to be used. If that doesn't suit your particular needs at the particular time, mix it with a little more or a little less water for the next batch (don't try to "re-temper" a mixed and slaked batch with more water).

Some of the newer hi-tech thinsets will make even an experienced person scratch parts of his anatomy when mixing per manufacturer's instructions, especially some of the non-sag versions. I can testify to that after having mixed several full bags in the presence of a manufacturer's rep one time. No way would I have believed the advertised water specification had he not been right there to say, for perhaps the fourth or fifth time, "No, no, just keep mixing, it'll work, it'll work." It worked.

We have had reports of some brands/types of thinset recently that are clearly marked incorrectly as to necessary mixing water. How will you recognize that? I dunno. :shrug:

Measure some out. Mix it. Make yard bunnies. Write off the cost to education. :)

My opinion; worth price charged.

ddmoit
03-30-2007, 12:52 PM
Scott, there's just no substitute for experience in this case. Fortunately, that experience can come pretty quick when it comes to thinset. I started out treating it with the precision I imagined would be necessary for making a nuclear bomb. Well before my bathroom was done, I had a pretty good feel for how much water to start with to end up with the amount of pookey I wanted. Now I might be lost with another brand of thinset, but I can mix MegaLite with the best of them.

It's time to quit asking questions about it and start mixing! :whip:

By the way, my wife is an engineer. I kind of know what you're going through. :D

ScottM
04-13-2007, 09:25 PM
OK, guys. I've become somewhat competent at mixing thinset, after wasting a good bit of it practicing. And I got my Ditra down without much trouble.

So now comes my next question. I've got six tiles down so far, over two days work. Yes, I'm working at lightning speed, thank you :crazy: At first, I had a lot of trouble getting my trowel to make good looking ridges (I'm using a 1/4x3/8 square notch). And I kept pulling up the tiles to make sure I was getting good coverage, which it was not at first. Thus, the slowness. But here is the question: what is the purpose of combing the thinset? Since setting the tile spreads the ridges out, why not just spread an appropriate thickness of thinset and go with that?

In all the books and videos on tile installation that I've seen, they always show the spread thinset with nearly perfectly formed ridges. As I said, I'm having trouble achieving that. But then I thought today, while laying some tiles, why do I need that? So in the areas where the ridges were less than ideal, I just blobbed down some additional thinset and placed the tile. This sped things up considerably. I got three tiles down in less than an hour, where it took me almost two hours to get three down Wednesday evening. I'm not looking to set any speed records here, but I do want to get this project done before summer. :shades:

Scott

ddmoit
04-14-2007, 05:52 AM
Scott,

I'm just hazarding a guess here, but I believe the whole purpose of ridges is to evenly distribute the right amount of thinset over the surface of the back of the tile - even distribution of the correct quantity.

I'm glad you hear that you got your Ditra down. I suspect your tiling speed will increase too. There's definitely a learning curve.

BigdaddyMike
04-14-2007, 08:33 PM
Hi Scott,

I'm no pro by any means, but I have watched alot of home improvement shows... HA HA HA HA HA :D

One thing that I have seen done time and time again is that with a larger tile (i.e. 12x12) they tend to "butter" the back of the tile and also trowel the floor to ensure good coverage... once they get about 3 to 4 tiles down then they will use a box level and ensure that the tiles are the same height... not necessarily level... by pushing down on the level any tile that may be higher.

This however, may be a good place for one of the pros to chime in and say if Im on or off the right track...

BTW... thanks for this thread... I too have learned alot from reading your questions... thanks.

Mike.

ScottM
05-03-2007, 03:53 PM
OK, I have all the tiles down in my bathroom. I'll be grouting this weekend. It was a lot of work, but it looks great so far.

But now I see a problem and I'm mad at myself for not seeing this coming. This bathroom leads to a hallway. I'm planning on putting Pergo laminate flooring down in this hallway. I have cut the tile to end in the doorway, and my plan is to bring the laminate into the doorway as well to meet the tile (with appropriate expansion gap, of course). But now that the tile is down, it is much higher than the laminate will be. I had planned to use a T transition piece to drop in the gap. But that will only work if both floor surfaces come up to the same level. :crap: I know Schluter makes transitions for this situation, but these require that they be embedded in the thinset and the tile set on top of them. I've already got the tiles down in the doorway, and I really don't want to have to bust them out.

Does anybody have a suggestion or know of something that will work in this situation? Thanks for the help.

Scott

GHR
05-03-2007, 06:06 PM
I think Pergo and others make those transistion pieces for more than just floors of the same height. Infact IIRC, I've seen a 'kit' where the U-track came with multiple transistion pieces that were to be assembled to create the desired transistion. So there were parts to be assembled to create step-up/down as well as the T-moulding in the same packaging.

Might not have been a Pergo product when I think about it. I might have been at an outletter here in town for wood/laminate/tile, but HD or Lowes surely has something similar.