Densshield or Hardibacker? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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03-03-2007, 09:59 AM
We are replacing a neo-angle shower enclosure in our upstairs bathroom. The original one installed 7 years ago has failed (cheap fibreglass Home Depot version) and we are replacing the pan with an Acrylic model. For the surround, we are planning a glass mosaic tile which requires a modified latex thinset.

I would prefer to use Desshield over Hardibacker...but have read on the net that the latex thinset will not bond to the acrylic membrane on the Densshield. Does anyone have any experience with this, or suggestions?


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03-03-2007, 10:09 AM
For what it's worth, I just set thousands of glass mosaics on Hardibacker using MegaFlex and MegaLite. No problems. Dampen the Hardibacker with a sponge as instructed before you trowel on your thinset.

I've never used the Denshield, so I can't comment one way or the other on it.

03-03-2007, 10:13 AM
Kyle , Welcome

I've only personally used dense-shield once a long time ago, But I've sat through one of their panel discussions and listened to another seminar on the product and was impressed with the knowledge of the company. If my memory serves me they have no problem with modified thinsets bonding to the board...In fact I'm certain that would be their recomendation. May check with your Glass manf. to see what they would like you to use. Some Glass companies have very specific bonding needs/brand preferences.

Do review the instructions for Dense-sheild if you go that route..They want seams and corners treated in a specific fashion for waterproofing.

We'll be here if you have more questions so feel free to ask away....Good luck and have fun. :tup1:

03-03-2007, 01:38 PM
Good thoughts guys, thank you. I have the old pan out and walls down...just praying the new pan fits relatively well in the profile of the ceramic floor tile that is left behind.

I am leaning towards the Densshield..but I am going to call the tile manufacturer (AdexUSA) on Monday to see if they have any specifications.

I will have more questions I'm sure so stay tuned!


Tool Guy - Kg
03-03-2007, 01:52 PM

Treating the edges of the Denssheild like Trask said is absolutely critical to this job lasting a long time. Many people have installed the material w/o treating the seams, and have regretted it. Do a search here on this site and you'll see tons of discussion on using the stuff.

In this case, I personally would choose Durock first, and Hardi second. It's my personal preference. :)

Calling the tile manufacturer for specific mortar requirements (and any others) is an excellent idea. :tup1: Glass tiles are not all made the same and vary in their requirements.

03-03-2007, 02:15 PM
if I recall correctly it's not just the seams with Denshield - it's also any penetration of the skin that has to be waterproofed. that means every place you drive a nail or screw to attach it to studs. and any plumbing penetrations. and the advantage of Denshield over Hardi is....? :scratch:

oh, that's right - it's easier to cut. :stick:

at least that's what I think I recall from my own research back when I considered using it and before I settled on Kerdi over drywall. :tup1:

03-03-2007, 02:27 PM
Good thought Art..any penetrations should be sealed on Dense-shield.

The other advantage over hardi/dura/wonderboard, is it is waterproof...provided you take care of the holes and seams.

I prefer Kerdi over drywall too. :D

03-03-2007, 02:57 PM
Now you're throwing me for a loop! Over what application would Kerdi be employed?

The new pan leaves about a three quarter inch gap between the ceramic floor and the pan on the outside edge of the neo-angle (in other words, the two sides fit nice, but the portion under the door is where the gap is) it possible to fill the gap with a filler of some kind, then use a fibreglass composite shoe moulding around the new acrylic base (properlly caulked, of course)? I DO NOT want to get involved with retiling the floor at this point...


03-03-2007, 03:33 PM
Our new neo-angle acrylic shower pan is not exactly the same dimensions as the piece of crap fibreglass one we just had to repace. I have not installed the new pan yet, but in a dry run I discovered when the pan is flush with the studs, the two sides of the angled portion fit the profile of the old pan, but it leaves about a three quarter inch gap on the longer side right under the door.

I was thinking I could fill this gap with a marine exopy/bondo type material, then buy a waterproof fiberglass shoe moulding to trim out the shower pan. After properly caulking, shouldn't this address the problem? Please don't tell me I have to replace the tiles.... :shrug:


Tool Guy - Kg
03-03-2007, 03:37 PM
Hi Kyle,

How wide is the gap? And is your new acylic pan solid, or hollow? :)

03-03-2007, 03:43 PM
The gap is approximately 3/4 of an inch... The curb of the pan is hollow. I am having my plumber install it after he fixes a drain issue we have been not sure if I need to address this problem before or after he installs the pan next week.


Tool Guy - Kg
03-03-2007, 03:46 PM
Hi Kyle,

I see you have two threads going on, so I've merged them. Let's keep your questions all together for this project to avoid duplication of effort and confusion. Plus the history of what led up to the latest question oftentimes changes the answers given out. :)

Ok, well, if you have that large of a gap and you think the quarter round molding you mentioned looks aesthetically pleasing, go for it. Make sure the plumber supports the underside of the pan per manufacturer's directions. Oftentimes it means a thin bed of mortar to support it. :)

03-03-2007, 03:57 PM
Thanks for merging the threads Bubba - still getting used to the site but I love it thus far.

Yes, I can get a hold of some pretty nice shoe moulding that will do the job. I will point out the issue to the plumber and make sure he adds the necessary support as needed.

I am still a little warry regarding which backer board to if anyone has more thoughts keep them coming. I was pretty surprised that there wasn't more water damage when I took the old surround and greeboard down, as the fibreglass had developed a few cracks and the old pan was not properly supported...causing gaps around the base of the shower surround. That issue is what got this project going...and since our one wall is only 65" from the top of the acrylic base to the ceiling we decided to tile. Most fibreglass surrounds come in stock 70" lengths...but the tile is a much better look anyhow.

Additionally, I am having a very well respected shower door contractor measure and install the door enclosure. the new tile will run about 1-2" outside of the enclosure...any suggestions on how to finish the edge of glass mosaics?

I know I have alot out there in this thread but I really appreciate the advice thus far. Thanks!!!! :clap2:

03-03-2007, 04:30 PM
Hey Kyle,
I used to use hardi quite often,and still do for certain applications, but in the last year have switched to denshield for shower walls. The acrylic coating on it that acts as a vapor barrier is very durable and makes a lot of sense to me. Why allow water to travel all the way through your tile substrate? Why not stop it directly behind the tile and it's mudbed? It also eliminates the step of installing a vapor barrier behind the substrate. As far as sealing fastener/plumbing penetrations, it's as easy as it gets (who likes to mud and tape inside corners?). Use a 100% silicone caulk, and get a neutral cure so you don't have to smell it as you use it. I use white so that when it's applied I can see that all spots are done properly. For the fastener spots, I just dab the caulk on my finger and apply it to the spots. I tool it around a bit to ensure adhesion. If your denshield is dusty prior to this step just dampen a sponge, wipe down, towel or let air dry, and then apply caulk. Doing this only takes about 10 minutes for a 30" x 60" shower.

One other benefit and an example of where "less is more" is that you can use a dry set mortar if you like and save a few more dollars, yet still get a superior product. The denshield doesn't suck the moisture from the t-set, allowing it to cure out the way it should. As far as the cutting of it goes, score and snap straight cuts, for plumbing holes I use a hole saw for pipes and a regular drywall saw (keyhole saw) for the valves. Super simple.

03-03-2007, 04:37 PM
Just re-read your first post and noticed the glass mosaic choice. When I mentioned using dry set I wasn't aware of the glass. Definitely use a highly modified thinset. Sorry.

03-03-2007, 04:50 PM
Thanks for the advice, no problem. I want to use the Densshield but I also want to double check with the tile manufacturer to be sure. It seems like the superior product from all I;ve read...just have to make sure it works with my applications.

On the densshield - does anyone have any experience feathering over it with drywall compound (for the area outside the shower enclosure that will not be tiled).

Rob Z
03-03-2007, 05:06 PM

Denshield will work just fine as long as you follow the directions. A good modified thinset will stick to it, and you should skim the area to be plastered with a thin coat of thinset. The joint compound or EZ Sand (better choice) will stick to the thinset.

In my opinion, as long as the fasteners aren't overdriven, then the same reasoning that explains why Kerdi doesn't leak holds true for penetrations through the Denshield. I have used Denshield on maybe 3 dozen jobs over the past 15+ years and haven't had any problems with it.

03-03-2007, 08:57 PM
Kyle - sorry to throw you that curve about Kerdi and drywall a few posts back. It's really not a good option with the acrylic base. :x:

I think one of your biggest concerns with this type of shower is that bottem edge of the wall just above the pan. It's somewhat exposed and thus it's critical to get a good seal in that area so water doesn't wick up into the substrate. That's where CBU has the bigger advantage as the material is solid. Be meticulous about following the Denshield instructions and tips from the guys who know and you'll be fine. :gerg:

Mike Finley
03-03-2007, 09:06 PM
We install DensShield almost everyday.

I recently returned home this weekend to glance over at a piece of 3x5 hardi backer board leaning up against a wall in my garage, there was a trail of snow melt water from my wife's vehicle leading right over to the hardi, I noticed that the hardi had wicked water about 5 inches up all along the bottom edge. :shake:

If you go to you can download a pdf of technical info on DS, and installtion instructions.

DS isn't just gypsum filled like drywall, even though it looks like it is and is workable like it, it is actually filled with a water resistant and mold resistant treatment.

Rob Z
03-03-2007, 11:59 PM

Back when all the hullabaloo started about Denshield, I set a piece in a pan of water and left it for several days. I never got it to wick more than 3/8" up the panel. I have torn out CBU showers which had the panels buried in the mud with no waterproofing, and the back of the CBU was wet 2, 3, 4 feet above the floor.

If I were a production tile contractor, I would use it with confidence on every job .

Rd Tile
03-04-2007, 07:59 AM
I have piece outside for 5 years now, cut open in the middle, been through 5 winters, snow rain and anything else that's out there, still hasn't deteriorated.:)

03-04-2007, 10:00 AM
I think if possible, fir the wall to the pan so that you do not have a gap.The gap is a problem because your membrane(or Dense-sheild) is now behind the upturned edge of the shower base. This makes it difficult for water to easily find it's way into the pan.
I think in this application Dense-sheild will work fine so long as the bottom edge of the dense is taken care of. I have used Kerdi over CBU/backerboard in many applications like this. Just like with Dense-Sheild though, you have to be very particular about how the wall/pan intersection is done. With Kerdi , I overlap the Pan and adhere it with liberal amounts of "Kerdi Fix" or Noble 150. I set my tile directly on the Kerdi that is left long and trimed after the tile is set.

ALSO....I believe there should be no vapor barrier/plastic/tar paper behind the Dense-Shield...Someone correct me if I'm wrong. :tup1:

Rob Z
03-04-2007, 11:19 AM
No vapor barrier behind the Denshield...that is in the manufacturer's destructions. :) :tup2:

03-04-2007, 12:28 PM
Allow me to clarify the gap issue.

Essentially with the 38" neo-angle pan, there are five sides: the two that are on the studs, and the three over which the door enclosure will be installed. The new pan fits nice and flush with the studs - no problem there. The gap is on the "angled" side - or the side of the pan under which you would enter and exit the shower once the door is installed. This area is, of course, a great place for water to accumulate when getting out of the shower - so my idea was to fill with a fibreglass epoxy, trim it out with a fibreglass moulding, and caulk. This would save a lot of time and heartache associated with replacing the abbutting tiles. :cool:


03-05-2007, 01:01 PM
Thinset question - our tile manufacturer requires a "latex modified thinset" for the glass mosaic sheets we are putting in.

Over at HD - I picked up 2 Set's "Fortified Thinset" - is this the same thing? On the product specs it says it is ok for glass, but wanted to make sure.

03-05-2007, 03:56 PM
I'd like to jump in here with a question too if I could.

Putting up glass mosaic tile on Denshield - the tiles call for a "latex modified thinset" and I picked up Custom Brand's "fortified thinset" - is this what I need? On the box it says it;s OK to use on glas mosaics.

03-05-2007, 04:03 PM
Hey Kyle,

The Brand HD carries is one many of us use Customs...I'm not sure but many may say "fortified"..kinda like my kids "sugar beastie breakfast cereal".

I would use Versa Bond Flex. It's almost always available at HD and it's a bit more "fortifed". There are a couple of better mortars and many I use as a two part fomula(dryset-unmodified with a latex/flexible additive.)By Customs that may be available. Here's a link to Customs mortar page...good info with pictures so you can be sure you get what you want. Read over it some good info

Tool Guy - Kg
03-05-2007, 04:06 PM
Hi Kyle,

I moved your question from the other thread into your thread here. That will keep 2 discussions from going in the same thread. I see that Trask is already on your question here, so you should be all good. :)

If you have any future questions for this project, please keep them right here. :)

03-05-2007, 04:15 PM

What brand of glass tile are you using? Did they make any specific brand recommendations for thinset?

For what it's worth, I have become a huge fan of MegaLite by Custom. I've not seen it stocked at Home Depot, but they probably can get it for you, or you can find it at a local tile store that carries Custom products.

As I stated in a previous post, I have set thousands of glass tiles in my bathroom, and I found the MegaLite to be well-suited for the job. It's highly modified, light-weight, won't sag, and has a pot life of nearly 4 hours. I don't have much experience with thinset, but I got real good at mixing small batches of this stuff. It was easy to judge the right consistency. The only drawback is that it costs nearly 4 times as much as something like Versabond.

Tool Guy - Kg
03-05-2007, 04:27 PM
Dan....4 times that of Versabond? :scratch: How much are you paying for Versabond and MegaLite?

03-05-2007, 04:32 PM
The Tiles are made by AdexUSA. I called down there today, and the guy who I got a hold of simple said "latex modified thinset," as the website says as well. It sounded like he actually just jumped online to look himself. Here's the link:

Also, I was just reading another thread and someone had used Redguard OVER the mortar that was used to seal the joints on the denshield. Is this necessary, or only if you overdrive the nails/screws?

I feel like with every decision I make with this project I am confronted with three more options. I wish someone would just set me straight!

I included a pic of the thinset I picked up today.

03-05-2007, 04:48 PM
Bubba, a bag of MegaLite (white) costs me about $41, and I have to drive about 40 miles to get it.

03-05-2007, 10:38 PM
OK, further on down the road...

We have been contemplating soap storage. I have read a lot about both niches and shelves on the site here, and I am intrigued by the niche but think a glass corner shelf (like Wilson Glass has out) may be a simpler solution. My concern on a niche in this particular application is tiling it using the glass mosaic - I have visions of the edges looking like crap.

So, under the idea that simpler is better, my question is - are there waterproofing issues wth using the Wilson Glass brackets THROUGH the glass mosaic? Or, does anyone care to comment on my novice ability to do a nice niche using 1) denshield and 2) tiling it with glass mosaic. :sheep:

03-06-2007, 01:13 AM
I've done several glass niche's and I thought they all looked sorta "sloppy"...crooked edges ect. I guess you like it or hate it.

We do tons of simple little slab corner and wall shelves. They are easily made on site and are easy on the wallet.

03-06-2007, 01:16 AM
Universal thinset? I don't think I've ever seen that.

03-06-2007, 05:32 AM

That thinset you have pictured has a pot life of only 30 minutes. That means you have 30 minutes to use it from the time you mix it up. I'm not a pro, and I'm certainly not that fast. The last thing I would want to be is rushed when I was setting my glass mosaics.

03-06-2007, 07:49 AM

Good point on the pot life issue. Hadn't even considered that. I think I will be switching to Versabond anyway, according to the feedback I've gotten on this thread.

Thanks! :clap2:

03-06-2007, 11:09 PM
Any advice on treating the area of denshield outside of the shower enclosure that will not be tiled? The counter man at my local (and very good) lumber yard said most of the guys he sells the denshield to have been feathering over the denshield with regular joint compound. Thoughts?

PS - Pic attached - to the left and above the shower head I was considering denshielding up to the ceiling. This is the area I had the question about.

Mike Finley
03-06-2007, 11:30 PM
GP's installation manual forbids the use of drying compounds with it's product, I believe it voids the warranty, but I may be wrong on that one.

Only setting compounds are to be used with it.

03-06-2007, 11:57 PM
Yes, when I asked him about setting compound he kind of hemmed and hawwed - and then said "most guys are using joint compound". I'm thinking b/c he didn't carry the setting comound?

03-07-2007, 12:13 AM
But your talking about outside the shower right? Who cares about that warrenty it gets painted :D

Mike Finley
03-07-2007, 08:53 AM
Probably right Trask, but I guess it's the same though process as why tape and thinset the seems on the DensShield on the shower wall that has the shower head on it, when all the water gets sprayed across the shower to the wall on the opposite side?

03-07-2007, 08:59 AM
Yea, for the little space outside the enclosure, why not use regular lightweight compound then seal it with a Zinsser or Kilz primer and paint it up?
It's not a big deal to go get the setting compund but I don't know if it's necesssary. If it were the opposite wall, or a ceiling, I culd see putting the effort in? :fish2:

03-07-2007, 10:52 AM
Inside the shower I it by the book...But outside I think it's not a big deal.

03-10-2007, 05:40 PM
Plumber set the pan in today. I know the backboard should come down over the lip of the pan...but wouldnt the board bend a little seeing as the lip creates a little 1/4 inch bump out away from the studs?

03-10-2007, 05:47 PM
Hi Kyle, what kind of pan? Prefab? If so run your CBU to the lip or fur the walls a 1/4".

03-10-2007, 05:49 PM
Some folks notch their studs so that the flange will be flush. Since your pan is installed already, the other option is to fur the studs out to be flush with the pan. You can purchase drywall shims if you can find them, or you can just make your own.

03-10-2007, 07:04 PM
Yes, the pan is already installed so I will have to shim the walls out. Glad I asked!

03-10-2007, 07:08 PM
Actually, a question. Should I shim out the entire height of the wall, or only the space rigth aboive the shower pan where there is a gap until the board flushes with the studs again as it runs up the wall? If I shim all the way up, the denshield will not be flush with the drywall that starts outside the enclosure...

03-10-2007, 09:05 PM
OK, according to the specs at the GP website:

Pre-Formed Shower Pan
Leave a 1⁄8" gap between DensShield and the
tub deck and completely fill the space between
tile and tub with a flexible sealant/caulk.

On the diagram (pg 6 in GP's website installation guide) it appears that the denshield actually abuts the top of the shower pan, and the area below is filled with silicone caulk, then the tile comes down over the space and is caulked there as well.

What do you think?

03-10-2007, 09:50 PM
The thing is, my plumber didn't mention at all about notching out the at this point I am perplexed (he did a sloppy job too, but thats another story).

If I fur out the studs completely, the transition to my regular drywall will be 1/4" bumped out (at least). The GP diagram really makes it look like the Denshield stops 1/8th of an inch ABOVE the lip of the shower pan, though the verbage says "tub deck". Of course, if the denshield stops above the lip the walls will be nice and flush, but I am not sure if this is the way it's supposed to be done. I am starting to hang the denshield on Sunday so someone please rescue me!!!

03-10-2007, 09:54 PM
Hi Kyle, you want to fur the studs all the way to the ceiling. Yes, leave what ever CBU you use 1/8" off the base. If you use Denshield you don't need a vapor barrier.

03-15-2007, 07:25 PM
Update: Thigns going well. Tiles came in today and I got them up tonight. Very happy with how it's turning out.

Rd Tile
03-15-2007, 07:32 PM
Just curious, how are the doors being installed over that pan and where on Long Island are you?:)

03-15-2007, 07:56 PM
NY Shower Doors is coming in to measure and install. Usual way it to drill tracks into the walls, then the bases of the doors are set in silicone.

In Central Nassau County here.

Tool Guy - Kg
03-15-2007, 08:54 PM
Looks like the pedestal is out of the way, but you may need some clear rubber bumpers for that glass door if it swings into the toilet bowl. :)

Rd Tile
03-15-2007, 08:56 PM
No problem, central Nassau huh, I'm in Hicksville.:)

03-15-2007, 09:04 PM
Yea, we learned to be careful opening the door of the previous enclosure :king:

L-town here, near Newbridge Road.

03-21-2007, 08:20 AM
Anyone have any thoughts about sealing the grout on glass mosaic tiles?

03-21-2007, 08:26 AM
I would think it would be fairly easy. Not much is going to stick to or penetrate that glass.

04-12-2007, 08:10 PM
All done guys - thanks for the help. Easter company loved the finished product.