# How bad is CustomBlend thinset?



## oh'mike (Sep 18, 2009)

I've never had any problems with Custom Blend thinset----Never heard of a problem from other tile workers,either----I think you are over researching this.----Mike---


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## TomServo (Sep 6, 2009)

Hmmm. Well, the folks at the John Bridge forums seem to think using it is a cardinal sin.

Have you heard any good things about it, Mike?

I mean, I get that it's not premium stuff. I understood that when I was paying the $6/bag, but there just wasn't another option for unmodified thinset and I though that was a bigger deal in this case. Turns out the modified is just fine on top of Ditra as long as you allow for additional curing/drying time.

Anyway, I think I'm going to just plow ahead and maybe get something better for the rest of the project.


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## racebum (Mar 8, 2010)

unmodified such as custom blend goes under the ditra, on top, well, as you mention it says unmodified but also goes into the problem with modified thinsets. cure time. personally i haven't had an issue with extended cure time and versabond which is actually modified

. unmodified is a void filler and customblend is a cheap way to go about it. i've used it under hardi and ditra with zero issues. the versabond is also a strong cheap modified thinset that again i and others i know of have had zero issue with.

as for as people who hate customblend. i promise you if it was $30 a bag rather than $5 some of those guys would like it more and talk about how easy it is to work with. while you get what you pay for is often true, some products like unmodified thinsets are cheap to produce and not everyone makes a large mark up


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## oh'mike (Sep 18, 2009)

I use custom blend and Mapi and latacrete---Never had a failure with any of them---


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## littlecleo (Sep 11, 2008)

I've used CustomBlend to bed backerboard, and never had any problems. I've also used Custom's modified thinsets - FlexBond, and VersaBond regularly, and never had any problems. Lots of different mortar brands/types on the market, and lots of opinions on the tile forums also, you usually only get to read the bad reviews.


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## TomServo (Sep 6, 2009)

Hmmm, I guess maybe I'm overreacting. I about crapped my pants when I started reading what people say about CustomBlend at JohnBridge.com, though. Its clear that there are better options, but its frustrating that Home Depot sells Ditra, yet can't supply a better mortar that's "compatible" with Ditra as Schluter would have you do it.



racebum said:


> unmodified such as custom blend goes under the ditra, on top, well, as you mention it says unmodified but also goes into the problem with modified thinsets. cure time. personally i haven't had an issue with extended cure time and versabond which is actually modified


No, I'm quite sure that a modified thinset is specified for bonding Ditra to wood subfloors (as is the case in my situation). Unmodified is specified between Ditra and tile. The rationale for this is that Ditra is a vapor barrier and will prevent/slow drying to an extent that unmodified will cure harder than modified, all else being equal (which it never is).


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## oh'mike (Sep 18, 2009)

I think that custom blend is used by many novices--after all it is sold at a store that caters largely to the homeowner---

This leads to a lot of failures---not because there is any thing wrong with the product---
Mainly there is a learning curve--proper mixing --proper application--open time--pot life

All those things that are learned only with experience----it is natural that the brand used most frequently by the novice will get the most complaints.

I find the brand to be just fine---If the complaints were from pros only,I'd have a different opinion

----Mike---


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## TomServo (Sep 6, 2009)

oh'mike said:


> I think that custom blend is used by many novices--after all it is sold at a store that caters largely to the homeowner---
> 
> This leads to a lot of failures---not because there is any thing wrong with the product---
> Mainly there is a learning curve--proper mixing --proper application--open time--pot life
> ...


That sounds quite plausible, Mike. I bet I made a few rookie mistakes, though, too. For one, the mix seemed a little thin, but I'd already dumped the measured water into the bucket. Well, it was a learning experience, anyway. I could deal with failure attributable to lack of experience. Choosing the wrong product is more of a frustration, somehow. I guess there's experience to be gained there as well.

Several pro tile guys did say to steer clear of the stuff, though. I think that's mainly because there are better options for nearly the same cost and not because CustomBlend itself is all that bad.


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## Jim F (Mar 4, 2010)

Were you able to use a 50# bag mixed? That sounds like a lot for 50 sq ft. Or is that the norm for floors?


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## oh'mike (Sep 18, 2009)

On floors 50# covers 60 to 80 sq.--He had Ditra under the tile-- so half went under--the other half over the top----That didn't come out right--Mike--


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## TomServo (Sep 6, 2009)

No, I used Versabond under the Ditra. One 50 lb bag did the job there with some left over for about 100 square feet.

Between the Ditra and the tile, I mixed a 50 lb bag and had about 7-10 lbs left over for around 45 square feet. Does that sound reasonable?

I think it works out. The Ditra handbook says one 50 lb bag for 40-50 square feet.


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## Bud Cline (Mar 12, 2006)

Listen,

Custom Building products makes some quality products and they serve the industry well. They do offer some entry-level products as do all of the makers of such products.

What you have to understand about the Bridge Clan is a lot of those guys are more Prima-donna than anything else. That particular group especially the regulars like to get free stuff from manufacturers and most all manufacturers are willing to oblige from time to time. Hell I get a lot of free stuff too and I don't hang out there anymore.

The thing is...Custom Building products is all business all the time. They aren't so easily talked out of gifts and free stuff though. Those guys over there tend to bad mouth people that don't do something for them on a regular basis. Custom don't give them stuff in other words.

In regular attendance over there are people from Noble Company, Hell one of the major heavyweights from Laticrete is a regular there, Of course they are all in bed with Schluter. Most all of the mainstream manufacturers watch what goes on there. They are in constant touch with CTEF and TCNA. So some of them see a lot of free stuff and a lot of them are ballsy enough to openly ask for something free. They have few scruples and don't mind prostituting themselves from time to time.

So...I wouldn't hang my hat on what they may have to say about Custom Building Products products. Take it with a grain of salt.

If you want quick first class installation information then that's the place to go for answers by the book, but beyond that there are other sites that offer the same.

Ahem! If you know what I mean.:yes:


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## TomServo (Sep 6, 2009)

Good to know, Bud. I will keep my grains of salt handy.

To be fair, Mr. Bridge, the man himself, regularly recommends Versabond, so I don't think they're all biased against Custom. They've clearly been drinking the Schluter kool aid, of course.

Ditra seems to get free press of all kinds. Its just too bad that a place like Home Depot isn't really supporting the uninformed DIYer like myself by selling higher quality products that meet the specifications for Ditra (which they also promote). Of course, if I had stayed completely uninformed, I'd probably have plowed right ahead with CustomBlend on the rest of the floor and never known the difference.

I realize that CustomBlend isn't so bad, but it would give me peace of mind to be using at least a mid-grade product. Non-economy-grade unmodified thinset just seems to be hard to come by, though.


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## racebum (Mar 8, 2010)

come to think about it, doesn't lowes sell the lacrete unmodifed? no idea if it's any better but it's more costly.


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## TomServo (Sep 6, 2009)

racebum said:


> come to think about it, doesn't lowes sell the lacrete unmodifed? no idea if it's any better but it's more costly.


They supposedly have the Laticrete 317 and/or Megabond. My local Lowe's stores don't stock either, though.


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## eschirch (Oct 5, 2010)

*Advice Ditra/Porcelain*

Just put Ditra on my balcony using Custom Blend. Seems to be stuck down good. I did Redgard the balcony good first and really push Ditra into thinset.

Question:

Best mortar for porcelain tile on top of Ditra?

User-friendly exterior grout? Balcony has roof so does not get too much rain... more likely to have snow blow in.

Thanks for advice


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## JazMan (Feb 17, 2007)

Ah....small world, your question was answered at the other place yesterday. Maybe you missed it.

Ditraset is the "official" best thin set for tiling over Ditra. As you may know, Schluter licensed Bostik (Hydroment) to make it to high specs and put the Ditra name on the bags.

Too bad you didn't find these forums before you used Custom Blend under Ditra outdoors. Hope it works well for you.

Jaz


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## Bud Cline (Mar 12, 2006)

Isn't Custom Blend the *wrong thinset* to use for this purpose?


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## StonemastersHi (Mar 2, 2011)

TomServo said:


> I've been working on tiling my kitchen floor over the past few weeks (yes, weeks...I know).
> 
> I'm using Ditra underlayment from Schluter and had been following the instructions to the letter, which led me to acquire some CustomBlend thinset mortar, made by Custom Building Products. Schluter recommends an unmodified thinset to use between Ditra and the tile. Unfortunately, I had no sense that the only unmodified thinset available at Home Depot would be such as subpar product, as I have read since using it.
> 
> ...


Sorry I couldn't be of any help sooner but I just stumbled on your thread and wanted to set the record straight.

1) You DONOT use Un-Modified thinset to bond any type of tile and stone underlayment (i.e. Schleuter Ditra or Cement/Fiber Board) to your plywood/concrete unless the underlayment manufacture requires you to do so, which I haven't come across.

2) I would never recommend a sub-par product. Custom is not a bad product but if you look at it's specs, neither is it great. Example: Laticrete 255 MultiMax or Laticrete Platinum carry a Lifetime warranty when installed per manufacture requirements. Laticrete will repair any damage as a result of the failure of there product. 

3) If an installer/contractor is telling you it's OK to use Custom, which most homeowners can buy at there local hardware store, it demonstrates the Level of Quality and commitment to customers long term satisfaction.

4) Never bond unmodified thinset directly to Porcelain. Most Porcelains are either Semi-Vitreous or Vitreous. Simply terms, Water absorption is almost none. You use a Unmodified thinset to adhere to Porcelain, when the water vaporizes you're left with only mortar adhering to a tile with very little porosity. Always use a Modified thinset such as Laticrete 253 Gold or Higher with Porcelain. In the case of using a Ditra system which requires the use of an unmodified thinset between the tile and ditra mat, simply pre-butter all your porcelain tiles with a modified thinset, allow to dry, than install with a unmodified. Dont' forget to backbutter your pre-buttered tiles wells to get good bond between the modified and unmodified thinset.


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## Bud Cline (Mar 12, 2006)

> In the case of using a Ditra system which requires the use of an unmodified thinset between the tile and ditra mat, *simply pre-butter all your porcelain tiles with a modified thinset, allow to dry, than install with a unmodified.* Dont' forget to backbutter your pre-buttered tiles wells to get good bond between the modified and unmodified thinset.


Now there's a new one!


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## StonemastersHi (Mar 2, 2011)

Bud Cline said:


> Now there's a new one!


Sarcasm?? In either case I hope I didn't confuse. Tried explaining so a consumer can understand. Personally not a big fan of using unmodified thinset with any tile but especially vitreous or semi vitreous tiles like porcelain. If you don't know, well Back Buttering a tile is simply referred to in the trade as a Bond Coat. Flat trowel the back side of the tile to get 100% coverage area. In the case of the Ditra mat in order to meet the manufacture specs requires an unmodified thinset. To get around this and still have a strong bond to Porcelain Tile, I recommend a Bond Coat of quality modified thinset such as Laticrete 253 Gold or stronger allow to cure overnight than install tiles per Ditra. Aloha


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## Bud Cline (Mar 12, 2006)

Appreciate the education.
Thank You.


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