Kerdi board
- Thread starter kcchiu
- Start date
The stupidest I have ever seen are women managers, those, in jobs, where an education is not necessary and they thrive on what they seemingly see, as power. They fear losing it for then, they go back to flipping burgers. Might be the same for men managers, but, I know for sure, it is with women. Those with the least amount of education has the most need to prove their self-worth in their job.
This is why I stay in the man's world, women on the whole has not evolved enough for me.
This is why I stay in the man's world, women on the whole has not evolved enough for me.
Last edited:
Sponsor
Paid Advertisement
Those are words spoken in truth. I am 58 years old, have worked a lifetime in various positions ( ones needing education & diplomas, and then, others you just got to show up) and given a choice of the sexes to work with or for, I definitely, would pick the males.
Oh, and your comment about they would slap you upside the head? That is my point.
This is basically very true,
"Strange as it may seem, no amount of learning can cure stupidity, and formal education positively fortifies it."
Stephen Vizinczey
Oh, and your comment about they would slap you upside the head? That is my point.
This is basically very true,
"Strange as it may seem, no amount of learning can cure stupidity, and formal education positively fortifies it."
Stephen Vizinczey
Last edited:
I'm not sure what you have against Jim, but it seems to me that he is correct. In the linked document (as well as this one: http://www.schluterkerdiboard.com/media/KB-BROCHURE-ENG.pdf), it clearly mentions that the fleece outer layer is for bonding with the thinset. The reinforcement layer is going to be there more for shipping and during install. Remember that the core of this product is extruded polystyrene. This is the same stuff that you find in pink or blue foam panels for insulation (XPS). When you buy standard XPS, it may also have a reinforcement layer (clear plastic, typically) to prevent damage during transport and install. XPS is vapor retardant as well as waterproof. The perm rating for standard XPS is in the ballpark of what your link mentions, so it is clear that the outer layer does not add to the perm rating.
Essentially, you could use standard XPS in place of the KerdiBoard, but would lack the outer layer to make a good bond with the thinset. XPS on its own wouldn't provide a good bond with thinset.
As to your question on the corners, it calls for Kerdi-Band with a min. 2" overlap.
Since XPS is waterproof, it wouldn't make sense for them to cover it with Kerdi (or similar). Why waterproof a waterproof material?
Essentially, you could use standard XPS in place of the KerdiBoard, but would lack the outer layer to make a good bond with the thinset. XPS on its own wouldn't provide a good bond with thinset.
As to your question on the corners, it calls for Kerdi-Band with a min. 2" overlap.
Since XPS is waterproof, it wouldn't make sense for them to cover it with Kerdi (or similar). Why waterproof a waterproof material?
In the case of standard XPS, the film is to give it additional damage protection. Go by the insulation aisle the next time you are in HD, Lowes, etc. The thinner stuff (1" and under) is typically trashed (especially when there is no film). It can still get cracked with the film, but it is less likely and the film all the pieces together if it does get damaged.
For the "30% less strength", what type of measurement are you talking about?
With tile installed: 1) it should never be soaked. 2) the tile and thinset will stiffen it up.
If the outer layer was waterproof, I would think that:
1. it would be called out as a feature
2. they would have bonded Kerdi to the board instead of another product
I have no connection with John Bridge (and have nothing against him or his site). I will visit the JB site on occasion, but that is about it. Like Terry's forum (and others) there is good and bad info. However, Terry's is really a plumbing forum, so you come here for plumbing. JB is tile, so it makes sense to go there for tile info (whether you agree or not). The fact is there is more than one way to set tile just as there is more than one way to run drain lines. If the JB site had one plumber answering questions, would I go there to ask plumbing questions or would I come here where I can get input from many plumbers? Same goes for tile. If I had a question, I would research and get as much info as I could from as many sources as I could.
I haven't messed with KerdiBoard myself (I like Kerdi + cbu), but just because I haven't used it, doesn't mean that I would automatically dismiss it from future projects. Depending on my needs, I would research the options and see what would work the best for that application.
Anyway, post up what they respond with. However, based on what I have seen, I suspect that Jim is correct. I know that XPS is waterproof and will provide the perm rating. The outer layer is just for bonding as far as I can tell.
For the "30% less strength", what type of measurement are you talking about?
With tile installed: 1) it should never be soaked. 2) the tile and thinset will stiffen it up.
If the outer layer was waterproof, I would think that:
1. it would be called out as a feature
2. they would have bonded Kerdi to the board instead of another product
I have no connection with John Bridge (and have nothing against him or his site). I will visit the JB site on occasion, but that is about it. Like Terry's forum (and others) there is good and bad info. However, Terry's is really a plumbing forum, so you come here for plumbing. JB is tile, so it makes sense to go there for tile info (whether you agree or not). The fact is there is more than one way to set tile just as there is more than one way to run drain lines. If the JB site had one plumber answering questions, would I go there to ask plumbing questions or would I come here where I can get input from many plumbers? Same goes for tile. If I had a question, I would research and get as much info as I could from as many sources as I could.
I haven't messed with KerdiBoard myself (I like Kerdi + cbu), but just because I haven't used it, doesn't mean that I would automatically dismiss it from future projects. Depending on my needs, I would research the options and see what would work the best for that application.
Anyway, post up what they respond with. However, based on what I have seen, I suspect that Jim is correct. I know that XPS is waterproof and will provide the perm rating. The outer layer is just for bonding as far as I can tell.
Jadnashua
Retired Defense Industry Engineer xxx
If you're going to make a fishbowl out of the stuff, seal any surface penetrations, just like you would if it was a through hole, then, even John should be happy, but it still won't leak if you don't. But, you never have Kerdiboard in a finished assembly where it is sitting in liquid water, there's always something on top of it like tile and thinset, or maybe Kerdiband if there's a seam, or KerdiFix. IOW, there's no water pressure, and the foam (aided by the surface layers) will prevent it from leaking.
FWIW, the melting point of polystyrene is 464-degrees F, which was why in a previous post I thought it should survive up to 212-degrees. It seems that is gets plastic at a much lower temperature (but does not melt), and in combination with the bonding of the reinforcement bonding layer, for safety, the max recommended temp for KerdiBoard is much lower. I'll also point out, I indicated I'd neither seen nor been trained on the stuff when this thread came out, and was basing my comments on the datasheets. One reason why I went to the factory for their training class, so I could better understand the product and its potential uses, which John has not done.
Another FWIW, in a steam room, if you can see a cloud/fog, what you're seeing is not steam! Steam is a colorless, odorless vapor and at standard sea level pressures is at LEAST 212-degrees F, and could be many hundreds of degrees hotter - there really isn't any upper limit to how hot you can make steam until it gets so hot, it breaks the hydrogen-oxygen bond and no longer is a water molecule (and that's REALLY hot)! From a practical viewpoint, there's no need for excessive temperatures in a steam room. Below 212, what you see is not steam, but condensed water droplets, i.e., fog, but it does start out as steam in the generator.
FWIW, the melting point of polystyrene is 464-degrees F, which was why in a previous post I thought it should survive up to 212-degrees. It seems that is gets plastic at a much lower temperature (but does not melt), and in combination with the bonding of the reinforcement bonding layer, for safety, the max recommended temp for KerdiBoard is much lower. I'll also point out, I indicated I'd neither seen nor been trained on the stuff when this thread came out, and was basing my comments on the datasheets. One reason why I went to the factory for their training class, so I could better understand the product and its potential uses, which John has not done.
Another FWIW, in a steam room, if you can see a cloud/fog, what you're seeing is not steam! Steam is a colorless, odorless vapor and at standard sea level pressures is at LEAST 212-degrees F, and could be many hundreds of degrees hotter - there really isn't any upper limit to how hot you can make steam until it gets so hot, it breaks the hydrogen-oxygen bond and no longer is a water molecule (and that's REALLY hot)! From a practical viewpoint, there's no need for excessive temperatures in a steam room. Below 212, what you see is not steam, but condensed water droplets, i.e., fog, but it does start out as steam in the generator.
Last edited:
Jadnashua
Retired Defense Industry Engineer xxx
Schluter says the max temp in any use is 70C in the tech data sheet...steam isn't steam until it is a gas, and, you cannot see steam, but the fog associated with a steam shower can still easily exceed the Kerdiboard's specs, as can the supply line. Water doesn't become steam until it is 100C, and once a vapor, it can get MUCH higher. The actual plastic doesn't melt until it gets to that 464, but that doesn't mean it remains the same solid and reliable stable material. And, being a foam, excessive heat could cause the closed cells, full of gas to expand, and create issues as it expands, delaminating, and creating further problems. There was no indication how they sealed any penetrations or how close the steam pipe was to the wall. Being a commercial shower, likely rather large room, ran long hours, and the steam supply was probably quite a bit hotter than on a residential one to be able to make suffient steam. If you know anything, you know steam can become very hot, a lot hotter than the 100C required at sea level to make it in the first place.
FWIW, the data sheet says 70C, whereas the (newer) Shower manual states 79C, so lessons learned can revise the acceptable use, or one of them is incorrect. But, the KerdiBoard tech sheet says to follow the Shower INstall manual, and nowhere in there under steam showers does it say KerdiBoard is acceptable - it only lists Kerdi and KerdiDS, depending on the local perm ratings required. IOW, following Schluter's directions, KerdiBoard is not designed nor supposed to be used in a steam shower...that it failed when used in one is not a reflection of it's proper use or capabilities.
Use the material as designed and intended, and it works. No guarantees when you do not.
FWIW, the data sheet says 70C, whereas the (newer) Shower manual states 79C, so lessons learned can revise the acceptable use, or one of them is incorrect. But, the KerdiBoard tech sheet says to follow the Shower INstall manual, and nowhere in there under steam showers does it say KerdiBoard is acceptable - it only lists Kerdi and KerdiDS, depending on the local perm ratings required. IOW, following Schluter's directions, KerdiBoard is not designed nor supposed to be used in a steam shower...that it failed when used in one is not a reflection of it's proper use or capabilities.
Use the material as designed and intended, and it works. No guarantees when you do not.
Last edited:
Guy48065
Member
Is that the melting point of polystyrene FOAM? Because I have built small temperature test chambers with the stuff (handy) and seen it shrink back at as little as 200F. According to Wikipedia (I know...) the solid polystyrene melts & flows above 212F. Foam would surely be less...
Last edited:
Jadnashua
Retired Defense Industry Engineer xxx
The solid polystyrene material becomes liquid at that temp (the raw material before it is made into foam). It can easily become unstable at lower temperatures, and Schluter says the acceptable upper limit on their product is 70C, or 158F, if I did my conversion math in my head right.
Guy48065
Member
Sounds a whole lot closer than the 464F you previously posted.
Jadnashua
Retired Defense Industry Engineer xxx
Lots of plastics get soft far before they melt. In a foam, you also have the entrapped gas that expands, distorting things. You can easily search this yourself...https://www.google.com/search?sourc...ting+point+of+polystyrene+foam&revid=77940401
Similar threads
