Kerdi is fairly easy. The Kerdi Shower thread that I posted years ago was my first Kerdi install. You have to start somewhere. And if he's a decent and conscientious worker, he might actually be more meticulous than most with this being his first Kerdi installation. Though I haven't touched it in years, RedGard is a topical membrane that's a vapor barrier too. The thing is, with topical membranes on a shower floor I prefer to use a flanged drain instead of using a divot method with a clamping drain. With RedGard, you'd have to use the divot method in order to maintain the weep holes. So Kerdi would work. Or he could use Aquadefense, but only in conjunction with a vapor barrier behind it. Me? I'd use Kerdi.

Hi Helen, I am nearing completion on mu first kerdi installation - a tub surround with a window in it. My only training was the Schluter website and this forum. Between the two I was able to do what I think was a quite reasonable job. My "lessons learned" for my next kerdi installation are: 1. Dont use hardi as the substrate - wicks too much moisture out of the thinset very rapidy. Use cement board (as opposed to fiber cement board) instead. 2. Use a premium unmodified thinset - simply for ease of application and final results. 3. Use large, unbroken sheets of kerdi as opposed to several smaller ones, thus minimizing seams. This seems intuitive, but because I used hardi I had to move quickly before the thinset became unworkable, hence the smaller pieces. I used kerdi, kerdi band, and kerdi fix and they all work well and have their place in the installation. I didn't use a kerdi drain because, as I said, this was a tub surround, but I wouldn't hesitate to try one of those either, as Mongo's thread on the topic is quite educational. Hope this helps. By the way, if you screw up a sheet of kerdi and have to take it down, just hose it off before the thinset dries and use it again (clean it well). I had good results with this, as I needed to pull a sheet off once. ggoose

What you need is to know how to search better. Key words are the question you need to ask. "What key words will bring me to the information I think I need?" Today, for you, good Key Words are membrane + shower (Betcha dint know that.) I entered these two words and got a lot of good links. The Noble company came up on top, in this search. Noble is one more good company like the manufacturers of the Red liquid membrane that you can trowel on, and the Orange sheet membrane that you can thinset onto your walls. In order to learn that Ditra is not made for walls, you have to read it on the web site of the manufacturer. After you see it from the horse's mouth, you waste less time asking questions that you could already know the answers to. When some experienced family person (your pa) tells you something, go hunting on the internet and keep rejigging the key words until you find you've got the right set of words. Don't try learning anything else before you go read the original source material first. Don't rely on oldtimers who don't read new information. Go to the source. Then, after that, discussion forums are great for the fine points. Not for the basics that you could have found out by yourself by opening a couple pages on the manufacturer's web site all by yourself. Ta-da! Have a great day. Hope this helps.

I don't know of anyone cutting corners or anyone who does shoddy work that then goes and spends money on Kerdi. The only people I know that use Kerdi are actually the higher-end guys. There's absolutely nothing wrong with a non-topical membrane shower. The only thing I'll caution is that the biggest sin I see these days is people still putting the floor membrane flat on the subfloor and then installing the deck mud preslope on top of the flat membrane. That without a doubt is not only a code violation, but it bad bad bad construction, and it's probably the number one killer of showers these days. Kerdi versus redgard, I prefer Kerdi. With Redgard I worry about mil thickness, I worry about pin holes... With Kerdi I have no worries. As far as a DIY book not having Kerdi or other topical membrane instructions, that's no surprise. They are usually years behind the times. Here's a fairly detailed instructional thread if you need ideas. Is Kerdi or Redgard overkill? I'll break it down into a couple of areas: 1) In new construction, thermal envelopes are much tighter today than they were 20 years ago. We have vapor barriers that are integral to the entire house, not just stud bay to stud bay. We have house wraps to help. We have windows and doors that are foamd in instead of gaps stuffed with fiberglass. We have cellulose and foam insulations instead o ffiberglass. Because air changes per hour have been drastically reduced, we have heat recovery ventilators to bring fresh air in the house while conserving BTUs. We soimply have tighter houses. As houses get tighter, moisture control becomes more important. That's why controlling moisture at the source is more critical. Kitchen vents, bath vents, minimizing moisture driven into and through the wall assemblies. Ths is where topical membranes like Kerdi and Redgard excel. 2) Older construction? Envelopes are leaky. fiberglass insulation that allows air to blow right through. The wind blows outside and you feel the draft around windows and electrical boxes. The thermal envelopes are so leaky that there are significant air changes per hour through the house. This allows any moisture that is created in teh house, or that gets into the wall assemblies, to zip on out. All that air movement, while resulting in high cooling loads int eh summer and high heating loads in the winter, prevents moisture from doing any damage to the house. So if moisture were to get into a wall assembly, no worries, because depending on the season, it'll dry to either the interior or to the exterior. So in an older leaky home, moisture control isn't necessarily as critical as it would be in a new tight home, so in an older home a Kerdi shower might be "overkill".