# Denshield and Moisture Barrier



## Floormasta78 (Apr 6, 2011)

First time using it, I will not install it. Dry wall guys will go it. 

Do I still Hydroban?


----------



## TNTRenovate (Aug 19, 2010)

Not according to the spec sheet. DensShield has a moisture barrier built in. That's why it's important not to sink the screws. All you need to do is mesh tape the seams and mortar over them. That being said, I would probably coat with Aqua Defense. Funny you said this, I was looking at it today in the at Menards. I think I am going to try it next bath.


----------



## Floormasta78 (Apr 6, 2011)

Aqua defense is like Hydroban. 
I worked for	guy once, he applied Noble over it because he was doing glass


----------



## angus242 (Oct 20, 2007)

I'd use FibaFuse fiberglass tape on seams and embed with AquaDefense. AquaDefense over screw holes too. 
Done.

The nice part about using FibaFuse is you can crease and use on wall/ceiling joint. Half of FibaFuse on wall gets coated with AquaDefense. Other half on ceiling can be finishes with drywall compound.


----------



## JohnFRWhipple (Oct 20, 2009)

We see a lot of Denshield here in Vancouver.

First coat with the liquid HPG. I coated out the shower with the second coat.

JW


----------



## CO762 (Feb 22, 2010)

Too bad there's no menards in canuckland JW because menards was clearancing their HPG for $21 in the pails.


----------



## JohnFRWhipple (Oct 20, 2009)

CO762 said:


> Too bad there's no menards in canuckland JW because menards was clearancing their HPG for $21 in the pails.


I bet the stock is out of date or been rotting on the shelves for years. I used HPG when I need to, like when I forget to buy Aqua D durning the week and pull a weekend waterproofing day.

I find it to thick for my liking.

Hydro Ban and Aqua D have the nicest texture and go on the best.

JW


----------



## TNTRenovate (Aug 19, 2010)

angus242 said:


> I'd use FibaFuse fiberglass tape on seams and embed with AquaDefense. AquaDefense over screw holes too.
> Done.
> 
> The nice part about using FibaFuse is you can crease and use on wall/ceiling joint. Half of FibaFuse on wall gets coated with AquaDefense. Other half on ceiling can be finishes with drywall compound.


Yeah, that's what I meant by coat it with AD. I was refering to the seams.


----------



## JohnFRWhipple (Oct 20, 2009)

Orlando make sure you clean the Denshield very well first. It holds a lot of drywall dust with the textured surface.

I've seen sheets of liquid membrane pulled off the Denshield.

We never roll the first coat of liquid. Always with a brush and burn it in good.

JW


----------



## Jaws (Dec 20, 2010)

What Angus said, except I use Dense Guard.


----------



## Floormasta78 (Apr 6, 2011)

Thanks for all the information gentlemen. John I will be sure to do so.. Always appreciated guys


----------



## Ethos (Feb 21, 2012)

Technically you're supposed to seal the seams and screwheads first with a waterproof sealant, then apply tape and thinset to the joints. Wedi/Sika urethane sealant works great and thinset adheres to it.


----------



## angus242 (Oct 20, 2007)

Don't get much more waterproof than AquaDefense


----------



## Floormasta78 (Apr 6, 2011)

Or Hydroban


----------



## angus242 (Oct 20, 2007)

That stuff is expensive and stinks :jester:


----------



## Floormasta78 (Apr 6, 2011)

Lol... smells like success


----------



## angus242 (Oct 20, 2007)

Smells like I'm paying too much :lol:


----------



## Floormasta78 (Apr 6, 2011)

Hahaha ! .. Common Angus, with deep pockets like yours , that's petty cash..


----------



## angus242 (Oct 20, 2007)

I have petty cash available because I use AquaDefense (it's the color of money)


----------



## Evan1968 (Dec 5, 2010)

Throw some of that cabbage this way Angus....heading to Coverings next week,need some spending cash!:whistling


----------



## angus242 (Oct 20, 2007)

I thought Dan was hosting....


----------



## Evan1968 (Dec 5, 2010)

Angus said:


> I thought Dan was hosting....


Hosting what? A gun party? He dont have 2 bullets to rub together.


----------



## TNTRenovate (Aug 19, 2010)

Ethos said:


> Technically you're supposed to seal the seams and screwheads first with a waterproof sealant, then apply tape and thinset to the joints. Wedi/Sika urethane sealant works great and thinset adheres to it.


Actually you are only supposed to mesh tape and mortar the tape, and caulk the corners and edges prior to applying the mesh tape.

2" (51 mm) fiberglass mesh tape–embed in a skim coat of
material used to set tiles on all joints and corners that are
to receive tile; caulk corners and edges prior to addition of
fiberglass mesh tape.

http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=3112


----------



## Ethos (Feb 21, 2012)

TNTSERVICES said:


> Actually you are only supposed to mesh tape and mortar the tape, and caulk the corners and edges prior to applying the mesh tape.
> 
> 2" (51 mm) fiberglass mesh tape–embed in a skim coat of
> material used to set tiles on all joints and corners that are
> ...


Like I said, caulk first, then add tape and bed it with thinset. I read edges as meaning the edges of the sheets itself, as in the seams. Am I missing something?

Edit: The reasoning behind this is that thinset is porous and not a water barrier, hence it requires a surface to surface sealant. Denshield, while being reinforced with fiberglass, doesn't hold up well if water gets beyond the membrane surface. Now what Angus was saying works as well as you would go surface to surface over the top of the thinset with a membrane sealant, creating the seal you want for the best water protection.


----------



## angus242 (Oct 20, 2007)

You can skip both the sealant and thinset mesh steps by doing the method I described above. It's cheaper (less materials) and faster (more labor $ in your pocket).


----------



## TNTRenovate (Aug 19, 2010)

Ethos said:


> Like I said, caulk first, then add tape and bed it with thinset. I read edges as meaning the edges of the sheets itself, as in the seams. Am I missing something?
> 
> Edit: The reasoning behind this is that thinset is porous and not a water barrier, hence it requires a surface to surface sealant. Denshield, while being reinforced with fiberglass, doesn't hold up well if water gets beyond the membrane surface. Now what Angus was saying works as well as you would go surface to surface over the top of the thinset with a membrane sealant, creating the seal you want for the best water protection.


I would not conclude that from the spec. It calls the area where two sheets meet a joint not edge. The edge would be where it meets the pan or tub. I didn't see anything about the screw heads. (not that I recommend their method) The screw heads should get a coat.

But I agree with Angus. I just waterproofed a shower today. Permabase, Fibafuse fiberglass tape and Aqua Defense. I put two coats on the mesh and one on the walls, more tomorrow. Still got the color of money on my hands as I type!

I am going to try the DensShield on my next job, using the same method.


----------



## Floormasta78 (Apr 6, 2011)

The DRY WALL guys are supposed to install.. I'm thinking I need to do it . I doubt, if I'm asking how to, that they know the right way of doing it.


----------



## Tom M (Jan 3, 2007)

The drywall guys will be too rough!!!! The only issue with the product is how sensitive the edges are. It must be handled with care so the facing doesnt delaminate.
I like denshield and always use it just like all the TNT and Angus. I use silicone on butt joints unless I am forming an opening or something that causes me to have thinset out. Because it is pourus you need to coat with liquid. With inside corners I tuck mesh and coat with liquid to build a flexible corner, when its cured I then lay silicone in the gap. Its a slower process than just siliconing first then liquid. 

The great thing about the liquid is it seals cut edges where silicone won't bond well and handles mishap repairs.


----------



## Ethos (Feb 21, 2012)

TNTSERVICES said:


> I would not conclude that from the spec. It calls the area where two sheets meet a joint not edge. The edge would be where it meets the pan or tub. I didn't see anything about the screw heads. (not that I recommend their method) The screw heads should get a coat.


And you're right that they should. The next sentence in the quoted paragraph is: "Seal penetrations and abutments to dissimilar materials."

It would also make sense to seal any joints between denshield with a waterproof sealant, as that hairline crack is an opportunity for water to get into the gypsum which will degrade the product, not to mention the framing.

I want to be clear that I'm not trying to call you out here, I'm just clarifying my position.


----------



## TNTRenovate (Aug 19, 2010)

Ethos said:


> And you're right that they should. The next sentence in the quoted paragraph is: "Seal penetrations and abutments to dissimilar materials."
> 
> It would also make sense to seal any joints between denshield with a waterproof sealant, as that hairline crack is an opportunity for water to get into the gypsum which will degrade the product, not to mention the framing.
> 
> I want to be clear that I'm not trying to call you out here, I'm just clarifying my position.


Seal penetrations and abutments to DISSIMILAR materials. Dissimilar materials would not be the two DensSheild sheets, seeing that they are similar. That's how I read it.

Penetrations = plumbing
Abutments to dissimilar materials = DensShield next to the pan.

And I don't feel like you are calling me out, we are having a good discussion.


----------



## Ethos (Feb 21, 2012)

TNTSERVICES said:


> Seal penetrations and abutments to DISSIMILAR materials. Dissimilar materials would not be the two DensSheild sheets, seeing that they are similar. That's how I read it.
> 
> Penetrations = plumbing
> Abutments to dissimilar materials = DensShield next to the pan.
> ...


Fair enough. The literature is ambiguous. I think we can both agree that either way, screwheads and seams of any kind should be waterproofed regardless of how lax GP is at clarifying their instructions.

Honestly, I had to agree with a poster on another thread when they said something along the lines of "They don't even specify what kind of sealant, only a waterproof one..." GP should lay down some specs on that.


----------



## TNTRenovate (Aug 19, 2010)

I am not trying to be an ass. I am just anal.

I agree they are ambiguis on their literature, but I don't follow their instructions. I try to go several steps above and beyond. I used to mortar my seams, but I adopted other methods, as described by Angus, using the fibermesh and AD.


----------



## Tom M (Jan 3, 2007)

To add to the conversation. ...
The product calls for blocking in the seams and silicone to maintain the water protection. I think mortaring the butt joints in the field is a better install because its stronger and keeps the boards from behaving separately. Plus it helps level out the joint should a course of tile land on it. With inside corners, penetrations and dissimilar material you need silicone so they can flex with movement.

I have called them directly to ask how they handle repairand again very vague but I did get them to agree a liquid brush on works well. There was some bond issue with that because the facing is already a skin and the liquid would only stick over it and not draw into it like cement boards. But its seems to work just fine.


----------



## Floormasta78 (Apr 6, 2011)

That's some good information Tom, thank you


----------



## TNTRenovate (Aug 19, 2010)

Tom M said:


> To add to the conversation. ...
> The product calls for blocking in the seams and silicone to maintain the water protection. I think mortaring the butt joints in the field is a better install because its stronger and keeps the boards from behaving separately. Plus it helps level out the joint should a course of tile land on it. With inside corners, penetrations and dissimilar material you need silicone so they can flex with movement.
> 
> I have called them directly to ask how they handle repairand again very vague but I did get them to agree a liquid brush on works well. There was some bond issue with that because the facing is already a skin and the liquid would only stick over it and not draw into it like cement boards. But its seems to work just fine.


Can't find any where in the lit where it calls blocking or silicone on the seams. Can you point to the documentation that states this?


----------



## Tom M (Jan 3, 2007)

http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=3112

At the end of pg3 they want blocking for 24" o/c. I think it was stricter in the past.
The next page they tell you to caulk all joints and seams prior to installing mesh tape.

They are very vague and loose with wording but the techniques for controls joints are the same for most board installs and considered standard.


----------



## TNTRenovate (Aug 19, 2010)

Tom M said:


> http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=3112
> 
> At the end of pg3 they want blocking for 24" o/c. I think it was stricter in the past.
> The next page they tell you to caulk all joints and seams prior to installing mesh tape.
> ...


So blocking is not necessary but in 24" o.c. construction, which would be very rare.

And as far as caulking the seams (butt joints), it's just not clear. It makes a distinction between joints and edges. That's what is confusing. Either way I would use the method that Angus described. I would caulk the bottom edge and that's it (on a tub or fiberglass shower pan). AquaDefense would take care of the waterproofing.


----------



## Tom M (Jan 3, 2007)

Ron you do whatever you want to do. I would not use caulking anywhere if you want to be anal. I bed mesh on inside corners with AD and it works great. I think GP brings to our attention that its the facing that is water proof and the seams need further attention, to them it seems squirting some caulk is fine. As stated before all control joints should be siliconed to allow for movement. I personally dont think I want any of my boards to flex in the middle of walls without blocking nor would I want a grout line landing near a moving joint so I thinset block and thinset them.


----------



## angus242 (Oct 20, 2007)

AquaDefense is a rubberized material. Do you know one of the properties of rubber? It's flexible. I stand by my original comments of embedding FibaFuse into AquaDefense on all seams.


----------



## Floormasta78 (Apr 6, 2011)

I'm thinking, to avoid you guys the headache.. 

Kerdi band EVERY JOINT AND GAP..

EVERYWHERE !..

Would that be an overkill.


----------



## TNTRenovate (Aug 19, 2010)

Tom M said:


> Ron you do whatever you want to do. I would not use caulking anywhere if you want to be anal. I bed mesh on inside corners with AD and it works great. I think GP brings to our attention that its the facing that is water proof and the seams need further attention, to them it seems squirting some caulk is fine. As stated before all control joints should be siliconed to allow for movement. I personally dont think I want any of my boards to flex in the middle of walls without blocking nor would I want a grout line landing near a moving joint so I thinset block and thinset them.


Again, the only time is refers to seams (joints) is to say that it needs mortar and mesh tape. It says to firmly butt these joints. What good is silicone going to do that Aqua Defense won't on the top of the seam?


----------



## Ethos (Feb 21, 2012)

TNTSERVICES said:


> Again, the only time is refers to seams (joints) is to say that it needs mortar and mesh tape. It says to firmly butt these joints. What good is silicone going to do that Aqua Defense won't on the top of the seam?


I agree that if you get aquadefense from one edge to the other completely covering the thinset and adhering to the surface of the denshield, then you should be fine. Either method works just fine in my opinion. :thumbsup:


----------



## Tom M (Jan 3, 2007)

TNTSERVICES said:


> Again, the only time is refers to seams (joints) is to say that it needs mortar and mesh tape. It says to firmly butt these joints. What good is silicone going to do that Aqua Defense won't on the top of the seam?


Because I would not want 2 boards in the same cross section flexing independantly. One of the reasons you thinset seams is for strength. I know aqua defense does crack isolation thats why I use it to bed fleece in corners and windows but its not ideal for impact on a seam in a wall. 
Maybe a spec in the TCNA better explains it. We all agreed GP language is loose. They basically say squish some caulk between the boards tight to avoid any further action while still sealing the joint. In the real world you dont always get boards that tight and dont want the silicone oozing onto the face and messing with the tile bond. So I gap my boards to control what I pump into them. Maybe Im more anal than you, I personally don't trust that alone either so I go the extra step of topping the seam as insurance.


----------



## TNTRenovate (Aug 19, 2010)

Tom M said:


> Because I would not want 2 boards in the same cross section flexing independantly. One of the reasons you thinset seams is for strength. I know aqua defense does crack isolation thats why I use it to bed fleece in corners and windows but its not ideal for impact on a seam in a wall.
> Maybe a spec in the TCNA better explains it. We all agreed GP language is loose. They basically say squish some caulk between the boards tight to avoid any further action while still sealing the joint. In the real world you dont always get boards that tight and dont want the silicone oozing onto the face and messing with the tile bond. So I gap my boards to control what I pump into them. Maybe Im more anal than you, I personally don't trust that alone either so I go the extra step of topping the seam as insurance.


But that's what I am saying. Nowhere on the documentation does it say to put caulk in between the sheets. It says to caulk the corners and edges, not joints. It says prior to mesh apply caulk to them. It doesn't say anything about caulk in the seams.

And leaving a gap between sheets is clearly against their installation instructions.

A thin layer of mortar isn't going to do diddly for impact. What's the thickest you are going to get it? 1/64th of an inch. Blocking would be the best bet, but again. I just don't think it necessary on 16 o.c.

This conversation has made me want to stick to CBU.


----------



## bluebird5 (Dec 13, 2010)

angus242 said:


> AquaDefense is a rubberized material.* Do you know one of the properties of rubber?* It's flexible. I stand by my original comments of embedding FibaFuse into AquaDefense on all seams.


:laughing::laughing:


----------

