Tile-Tape Nylon/PVC Composite Tape - 100' Roll

First, let me say that I am a big fan of the Strait Flex brand of drywall products. We use strait flex all the time and never get drywall call backs. It is fantastic stuff. So when I discovered the tile tape I was looking forward to trying it. It held out the promise of being able to tape up a CBU shower in the same manner as you would tape up a room with drywall, while at the same time providing water tight seams with superior strength over alkali resistant mesh tape. It didn't quite work out that way.In the promotional video for this stuff on youtube you see the tile setter working with this stuff in the same way he would with drywall strait flex and joint compound. That is only possible if you use the tile tape with Joint Compound. It doesn't work that way with Portland Cement based thin sets, even though the instructions say to use it with cement adhesives the same as you would joint compound. It just doesn't want to stick and stay stuck with cement based products the way it does with the gypsum based products. I put this stuff through its paces and tried several ways of adhering it. I used regular thin sets, modified thin sets, straight Portland Cement, and Portland cement with PVA. I also tried all these things with thin and thicker mixes. I tried priming the CBUs first with bonding primer. In the end the result is the same, it pulls away too easily from the backer board surface. It was difficult to keep it stuck to the Cement board while it was curing. Of all of my tests I found that Rapid set thin set worked the best if applied heavily. I literally had to bury the tape in the mud because if I didn't, even when dried it would pull away from the board much easier than it should. Strait Flex claims that this tape is far stronger than mesh tape. I have no doubt that this is true, however, the strength of the joint is only as good as the adhesion of the tape. The tape may be strong, but if it loses its bond from the material easily that really doesn't matter. By totally burying the tape in the mud and letting it dry, it probably creates a strong joint, but it makes it more difficult to tile over already dried joints because of the humps it creates. With tiling, it just works better and produces better results to tape as you go with the tile, and this product hasn't changed that.The product worked great when using setting type drywall compound to do the peripheral seams between the CBUs and the drywall, but this doesn't help in the body of the shower where you wouldn't want to use a gypsum based adhesive, even the water resistant "Hot Mud". I imagine this tape may stick better if mastic is used as the adhesive, but we never use mastic to adhere tile to anything other than a back splash so this would not be of consequence to me. I suppose you could tape the whole shower using hot mud and tile tape, and then come back and seal everything with hydroban or red guard and that might work. But then why not just use the regular joint fabric with membrane if you are going this route?Another claim that I wonder about is the one they make about waterproof joints. Give Strait Flex credit for using the term water proof rather than water resistant, since the words water proof have almost been driven from the market place thanks to the lawyers. However, I still wonder about this claim. Cement wicks water easily. The tape is only about an inch wide in its non perforated section. A half inch is not very far for water to wick on each side of a corner. Unless the tape is used in conjunction with a membrane such as Hydroban or Red Guard, I cannot see it as being more than water resistant, because in a truly wet area the water would wick into the corner that small of a distance easily. There is a reason Kerdi has a minimum width of band that must be used before it is certified as water proof, and that is several inches.Don't expect to use this tape like you would drywall tape. Because of the embedding problems you can't just tape up the shower, let it dry, then come back later and tile over. It works fine if you embedded and then immediately tiled, like we have always done with the mesh tape. Working with cement based adhesives in not like doing drywall work. If you try to tape things and let them dry before you tile it is much harder to keep the tile in plane when actually setting the tile because of the humps created by the dried cement. So you have to embed as you go to keep from creating rolls like you do with drywall work. I had hoped that this product, along with edge tech CBU boards would have solved this problem by allowing a shower to be taped first and then later tiled, but it doesn't. Cement based adhesives are just not thin enough to do this with, and even straight Portland cement without sand, which is very thin, doesn't work because it is not tacky enough to hold the tape adhered completely while wet. So in the end working with this stuff is not so much different than working with the mesh because you have to set it in the joint as you lay the tile. The only real advantage being that it folds in corners easily and doesn't get hooked by the trowel easily. However, whether it can produce a stronger joint because of the adhesion issues I found, I am not sure of. It certainly doesn't if applied like drywall tape where it is allowed to dry before continuing. It may be stronger if embedded thick at the time of tiling though. One day I will have to set up a bench test and see.I have not given up on this tape completely yet. There are still some things to try. Like it might be suitable to use instead of the fleece when making water proof angles with HydroBan or Red Guard. Using the membrane to adhere it rather than a cement. This seems plausible, but then why not just use the products made for this type of water proofing? For now though, I don't see it as a complete replacement for any of the products we are already using for CBU showers, such as mesh tape and reinforcing fabric. Unlike the Strait Flex drywall products, this one doesn't have me sold on the concept completely yet.Update:After further field trials I find that this stuff works like a champ with Megalite thinset. Just like running strait flex with drywall and gypsum muds. I haven't tried it with Ultralite yet but I assume it will perform the same. Most of you probably don't know what Megalite is because you can't buy it off the shelf at the box stores, but you high end tile guys know what I am talking about. Good news for you box store shoppers though, you can special order Magalite at the pro desk at HD, and Ultralite at Lowes. It is expensive, but you get what you pay for, especially with builders. I like working with the light weight thin sets. So now that I know it will work well with Megalite and since have been using more and more of the light weight materials on upper floors in the past few years, I think it is time to buy a case of Strait Flex Tile from Amazon. It now seems to have found a home in the bag of tricks. I raised the review to four stars.