Tadelakt -- a waterproof plaster surface

This subject has come up a fare bit over the last few years...I thought it warranted its own post that could be referenced for helpful info and a place to chat if anyone has questions...Please Enjoy

Imagies of Tadelakt

Tadelakt Instruction

Tadelakt Instruction

Morocco Design Co.

Athen Art Tadelakt

PureTadelakt - Lime plaster from Marrakech

Easy Tadelakt Note: just for reading as this is a "reping company" I question some of the links?

Tadelakt Traditional Blog

Mike Wye Tadelakt Mike's awesome...say hello from me...

Lime Works Great folks and again don't feel shy about dropping a hello from me. These folks and Mike just above will answer many questions about traditional lime working.

Canelo Project Interesting infor, great group of folks for those of us in the New Mexico area...say hi.

Here's my first! and only, so far. My teen-aged daughter's bathroom. Tadelakt over gypsum plaster on drywall. The second photo is a crack developing already on the wall that has been covered in cement board and taped with OPC thinset. We were going to tile the wall, but the tadelakt is so beautiful, we decided to cover this wall with it instead of tile. This is the back side of the shower wall, so I don't think it will fail, but I'll never do this again. Tadelakt over gypsum seems to be working great though.

Bill, curious, in retrospect, how would you do this differently? what did not work?

siu-yu man wrote:Bill, curious, in retrospect, how would you do this differently? what did not work?

In retrospect, I would not use any OPC based products with any kind of lime plaster. They behave too differently and this resulted in cracks appearing at the seams between the sheets of cement board.

Gypsum and lime get along famously. The predominant plastering system in homes 100 to 150 years old is lime render, gypsum plaster and then colored lime top coat, so this is what I mostly use in my restoration work. A modern interpretation of that system is what you see in the first photo. I installed drywall on the stud wall, then plastered that with a greenguard certified all purpose joint compound then top coated with type s hydrated lime aged 1 month mixed with brick slurry from a brick saw, application by 6 inch brush and immediately trowel burnished, dried leather hard and then local goat soap dissolved into warm water is painted on with the same 6" natural bristle paint brush and burnished with a cut piece of local limestone.

I am a restoration contractor, so I always have a bottom line. I experiment with combining ancestral techniques with modern industrial products on my own home in order to work out the bugs before doing any job professionally. This really isn't natural building, so I have been reluctant to share some of my techniques here on Permies, but I have decided that less than perfect is sometimes good enough.

Is there a ratio of soap to water for use in tadelakt application?

Hello Kris,

Bill can expand this perhaps if he can, but you don't (at least in most...not all) formula recipes, add soap to the mix. It is only employed as a "burnishing paste" to render a more water resistant surface for lime plasters in damp and wet areas such as bathrooms, kitchens and patios. This is a detail process and I hope to publish more when I can...

Regards,

j

Hi Kris,

First start with a really good lime plaster that is heavily burnished so that it is starting to polish. Then shave a bit of olive oil soap into the water, not so much that it gets all soap bubbly, but enough to see that there is soap in it. Then take a good polishing trowel, one that is highly polished and flexible and polish the soap by painting on a bit and burnishing while wet. The soap and the free lime on the surface react chemically to create calcium stearate, aka soap scum. The scum waterproofs the plaster by filling in the pores as you burnish.
I don't use a stone, just a good stainless steel trowel, but I'm not going for waterproof, just stain and water resistance. The polish makes for great lighting and gives the room a glow.

I'll post some more as we finish the polish.

All Blessings,
Bill

Thank you for the tips Bill! I'll be taking a tadelakt course at the end of the month with Ryan Chivers, so hope to gain some more insight into such a great finishing technique!

Hi Kris,

You are very welcome.

This is a great technique, for keeping fit as well as waterproofing!

I have been learning this finishing technique from Ryan, who will hopefully join our little LimeStrong team.

Send me a PM if you would like to stop by our place in Richmond(we're basically on the way to Driggs) and talk lime plaster, natural building or whatever.

All Blessings,
Bill

When I get around to doing solo tadelakt projects, I'll post some more pics!

Hey,
have you any experiencies of "easy tadelakt" -company, can I trust it? I'm planning to order for about 1000 € and started to hesitate.
Veijo from Finland
PS. thanks for the informative page!