For below grade stem walls, is it easier to just use a peel & stick membrane like that what Nudura sells or do a parge cement coat to protect the ICF below grade?

Peel and stick doesn't stick if the foam is exposed to sun for even a month.

PolycreteUSA recommends using a liquid applied waterproofing membrane, as adhesion is more consistent.

Or a primer like Henry specs beneath their peel and stick WP-200... I don't know how much of a problem adhesion is to the ICF, as long as it adheres to itself, that is what really provides the waterproofing/continuous membrane. Do you need waterproof or just protection? A parge coat would probably protect it just fine, but probably wouldn't be especially waterproof. If using a peel and stick It will of course need to stay in place long enough to complete the backfill, and if you are not backfilling it will have something else placed over it(and most likely screwed thru it) anyway If you are backfilling that will ultimately hold it against the ICF. Since the backfill can possibly damage the membrane it most likely needs some form of protection such as a screwed attached drain board/capillary break layer or additional foam sheeting(also serves as a drain board) to protect the membrane from the backfill process... All of this will help hold it in place. The protection also applies to coated membranes to help keep them watertight as well. But since the coated is a single step, that might be a little easier. I think the peel and stick being typically thicker than a coated layer does a better job of staying watertight if that is a concern.

Dimpled membrane. It's about as goof proof a water proofing you can use. Cost less and installs in 1/4 the time. No worries about rain or condensation. You can install it 10 seconds after you pour your wall because the bleed water doesn't effect it. It makes no sense to use peel and stick.

It's not clear to me what the underground ICF is being protected from. Or what's on the interior side of the OP's stem wall (could be dirt which makes dimpled membrane not so smart).

It is the same as a regular concrete wall. The protection is an attempt to stop future leaks. Leaks can form around the plastic ties, cracks in the wall, or just seep through the wall.

I am not a fan of peal and stick after using it on my current build but am surprised by the spray on fan club. It must be put on thick to seal the joints between the foam blocks. Dimple method is good but the most costly also?

Dimple Membrane! Thanks for that, I could not remember that yesterday to save my life That is what I was thinking when I said drain board Yea the dimple membranes I was looking at were pretty costly. So costly I opted to use 1" below grade XPS over my peel and stick. this was less expensive, and it adds another R5 to the wall...

$.40 per sq ft is expensive? Order it online from Super Seal and have it delivered to your house. I'm in the business and the best price for peel and stick is far above that. As I've already stated if your time is of no concern then keep doing it the old way. Spending more time on a job is not my thing. Especially if it comes at a higher cost

Sorry I just checked and it's $.45 per sq ft plus $10 for shipping. Now that's expensive.

Wow, I never found it that cheap, I will have to check that out, thanks.

Sorry, not trying to bust you but there are better and cheaper ways to accomplish the same thing. I haven't sold or used peel and not stick for at least 9 years, if not longer.

With a dimpled membrane, be sure that you have the drain in place. Otherwise it may just hold water against the wall (the opposite of the intended function).

What kind of idiot would go to the trouble of applying a waterproofing product and then not use a footing drain system. Thank you for that pearl of wisdom. Best system while we're at it, is Form a Drain hands down. If I were building another house, that would be what I would use.

Doesn't the membrane also protect the ICF from damage due to backfill?

It should also protect the underground from termite intrusion since they can't tunnel through a membrane.

Yes the membrane should protect the ICF from the backfill...

The peel and stick has weaknesses that the dimpled doesn't. It can be damaged during back fill and allow water behind it. I've had calls on three jobs that have had water intrusion. All three were p&s. Two were caused by rocks being used against the icf and one was caused by sloppy seam work. Even if you poke a hole in dimpled it still does it's job. The only two things that can cause it to not do it's job are: fill behind the membrane with back fill dirt and not putting stone on top of the footing under the membrane so that the membrane becomes flattened by the weight of the back fill.

The problem with dimpled is that it doesn't provide any termite protection. Termites can still crawl underneath it and tunnel through the foam. Or am I incorrect?

Polyguard makes a peel & stick with a water based adhesive for ICF below grade. They also have a product called "Poly Flow" which protects the ICF during backfill and drainage.

If I can add a dimension to this discussion - I have a full basement, which I have decided to protect with dimple board and a footing drain to daylight. But the area where my garage is has a 4' stem wall. I plan to protect it with the same dimple board on the outside. Do I also need to damp proof the EPS on the inside before the under slab area is backfilled? The dirt has some minor moisture content, which I presume will dry out by the time the slab is poured. With the footer drain and considering I'm on the top of a ridge, I don't really expect the inside of the stem wall to have to handle any moisture. What say you guys who have been doing this for a while.

Usually we overlap on a stem wall that attaches to the main foundation about 6'. This should be enough to drain into the main lines. Lbear if you live in a termite prone area , use a product like Black Jack 57 under the dimpled membrane. It doesn't dry hard and the little critters find it very gummy for their choppers.