I know that this has come up before, but I'm still not clear on how to handle siding transitions at ground level over ICF. I have peel and stick on my ICF below grade, and for a ways above grade. Then I have dimple board over that. I'm planning a 1/2" thick drainage plane under Hardi Plank siding. I haven't decided on a siding for the lower level- either Hardi Board board and batten, or stucco. My question is- What happens at ground level? You have to keep fiber cement at least 8" above grade. Also- the dimple board is pretty thick. If I run my siding down to the dimple board. it would tend to block the ventilation of the drainage plane. Also, you would want to conduct and water behind the siding OVER the dimple board, not behind it- right? Likewise, if I stucco the basement portion, how do you keep the thickness of the stucco from blocking the drainage plane behind the siding, and again, keep moisture from behind the stucco.

I'm just not seeing what happens either at ground level, or in the transition from stucco to lap siding. Thanks!

The "stucco", or parging, doesn't have to be very thick and it can taper up under the Hardiplank without blocking the ventilation if you use a thin applicator trowel. I did a thin layer of cementitious goo, applied a fiberglass mesh reinforcing strip and then another layer of goo. I think the "goo" was Sto BTS Plus. I covered the top gap at the drainage board with a strip of peel-and-stick. I roughed up the surface of the peel-and-stick with 60 grit paper and wiped it with acetone for better adhesion of the parging and it seems to work pretty well.

I would use a metal drip cap profile, which you could purchase or have custom made by your local metal building/roofing supply company. They probably have at least 20 color options. If it is to be installed on a side that is subject to wind driven rain you could perhaps specify a longer leg to go up under the siding farther ( maybe 4" ) and leave a fair amount of anti siphon space say 1/2" between the bottom of the siding and the top of the drip ledge. Typically, the drip cap ledge is 1" wide, before it turns down, but you should be able to have that made wider if necessary. And always remember to " make it look like it's supposed to be that way !".

With Hardie siding the traditional water table trim looks great and gives you an excuse for different thickness. http://www.hammerzone.com/archives/exterior/trim/water_table/pvc.htm is a quick show and tell.
The trim pushes the water running down the siding away from the parging and basement wall.
Most stucco suppliers have prepackaged parging for under the trim to below ground. It is best to divert the water over the dimple material but not essential. That is why the dimple is used. It provides a free flow down to the footing drains.

Thanks for the ideas! I especially like the water table trim. If I can get the hang of stucco, I'll probably do the whole lower section in stucco, as I imagine it would be cheaper than Hardi board. I went to the hammerzone article on fiber cement siding, but noted that they didn't use a drainage plane, and didn't leave a capillary break at the water table trim. I'm guessing that you would have to use well-secured lath over the dimple board, and then gradually taper down the thickness of the stucco as you go up the wall.

My basement is a walk-out, so there is 8'+ of basement wall in the back. I'm not worried that much about appearance, but want a low maintenance finish. I don't like the appearance of 'stair step' siding as the grade drops, but plan to keep the siding level, with a gradually larger basement reveal on the sides. In the meantime, if I win the lottery I'll have the basement done in stone or brick.

Posted By jdebree on 30 Aug 2013 06:47 AM
Thanks for the ideas! I especially like the water table trim. If I can get the hang of stucco, I'll probably do the whole lower section in stucco, as I imagine it would be cheaper than Hardi board. I went to the hammerzone article on fiber cement siding, but noted that they didn't use a drainage plane, and didn't leave a capillary break at the water table trim. I'm guessing that you would have to use well-secured lath over the dimple board, and then gradually taper down the thickness of the stucco as you go up the wall.

My basement is a walk-out, so there is 8'+ of basement wall in the back. I'm not worried that much about appearance, but want a low maintenance finish. I don't like the appearance of 'stair step' siding as the grade drops, but plan to keep the siding level, with a gradually larger basement reveal on the sides. In the meantime, if I win the lottery I'll have the basement done in stone or brick.

If you use a pvc product for the trim, I won't worry about the capillary break behind it. I would put flashing on top and up behind the drainage plane strapping and house wrap. On top of the flashing I would use a product like Cor-a-vent wall vent http://www.cor-a-vent.com/siding-vent-sv-3.cfm Please note that in the drawing they have their enhanced insect screen on top. It should be on the bottom so that insects don't block the vent tubes.

On my house because I am using stone under the Hardie, I had my custom metal shop make up a metal trim that looks like the top piece of the water table but with a large tapered face so that the top is 1.25" out from the ICF and the bottom is 2.5" out to cover the stone product. It should give me a neat maintenance free transition.

For now I'm just going to put on a base stucco coat c/w mesh and then later as I have more time, I'll use the same product to apply the cultured stone.

Okay ! So, now I too would use a custom metal profile water table trim flashing and the " Cor-a-vent " like "FBBP" suggested. Now that I know it is available. And, if I lived near salt water, which I don't, I might have the trim made up in copper. Anything worth doing on your own house is worth over doing, right ?

On an ICF home that transitions from EIFS to cultured stone the bottom 4 feet of the wall. Does one have to do anything special at the transition from stucco to cultured stone?

Since there is no "drainage plane" behind the stucco and EPS, as the stucco is bonded directly to the EPS. I have been told the cultured stone is applied directly to the EPS with just a metal screen and then the stone.

Posted By Lbear on 31 Aug 2013 06:43 PM
On an ICF home that transitions from EIFS to cultured stone the bottom 4 feet of the wall. Does one have to do anything special at the transition from stucco to cultured stone?

Since there is no "drainage plane" behind the stucco and EPS, as the stucco is bonded directly to the EPS. I have been told the cultured stone is applied directly to the EPS with just a metal screen and then the stone.

If I understand right, you are planning to use just acrylic stucco rather than EIFS. That would indicate that your stone will project in front of the stucco by about 2". This is awkward both from looks and water running down the wall and possibly getting behind the stone. One solution might be to make a water table out of foam such that it is big enough to look good and will overhang the stone by about 1/2 to 3/4 of an inch. On the underside, you route out a half moon about 3/8" fro the front edge. This then form a drip edge such that the water running down the stucco wall will be projected out away from the stone.
The stucco guys will wrap the whole think in mesh and glue it in place with their base coat. They may also know a foam outfit that makes these up just like they make up the cornices and other foam trims.
If you want to take it a step further, you can finish the water table to look like a sand stone ledger on top of the stone which will help to make the transition look natural. Depending on colours, it can sometimes be hard to make stone with just stucco over look good. Sometime the sandstone look helps, other times you might have to add some other texture like wood to blend things together.

It would look like something along these lines:





I found this detail but it's for a wood frame wall:

I found this article:

Adhering Stone Veneer to ICF Walls

Interesting that the quoining does not appear to be attached with lath but the stone is.

Posted By FBBP on 03 Sep 2013 09:06 AM
Interesting that the quoining does not appear to be attached with lath but the stone is.

Maybe they installed it prior to doing the stone?

What do you think of that detail I posted?

Posted By Lbear on 04 Sep 2013 02:27 AM

Posted By FBBP on 03 Sep 2013 09:06 AM
Interesting that the quoining does not appear to be attached with lath but the stone is.

Maybe they installed it prior to doing the stone?

What do you think of that detail I posted?

The detail meets the two requirements. It makes a nice transition and it pushes the water away from the wall

I'm planning a 1/2" thick drainage plane under Hardi Plank siding.

I'm pretty sure I know why you are planning a drainage plane under the siding, but I have to question whether it's necessary. What are we afraid of? The cement board is not going to rot. It will dry eventually, because it's not sealed at the laps. You've got nothing that will decay behind the siding, or behind the foam. So what's the worry.

Regarding the transition. I used this stuff

http://styro.net/TuffIIFoamAndICFCoating.html

It goes on nice. I decided to spray it with a cheap drywall texture gun. I does stick to the peel and stick, but not as well as it sticks to the foam. It can go below grade.

A local contractor that does ICF stem walls will overlap the dimple board with aluminum and bring it high enough to go behind the starter strip. If you bring your siding low enough, it probably isn't noticeable. I don't know if this is good practice or not.

Regarding the L-flashing, I bent some gutter aluminum (thick) on an 8' brake. I have the aluminum finish showing and it looks like stainless . . . and it won't ever rust! My HVAC sub let me use his brake. You cannot bend that stuff with a conventional siding brake.

The stuff used for steel buildings are made out of steel and then painted.

I've considered going without the drainage plane. From what I read, you want the siding to dry quickly to preserve the paint and prevent mold. Our climate in SC has a fairly normal amount of rain, but this last year has been unbelievable. We've had above average rain every month, and almost 24" in July, followed by over 12" in August. I had some scrap pieces of Hardi laying on the ground that stayed wet, and the stuff falls apart if it stays wet long enough.

While I'm sure it will work without the drainage plane, I want the lowest possible maintenance going into retirement. I don't want mold or algae all over my siding in 5 years. I'm kind of torn, because if i have a drainage plane, there will be condensation behind the siding due to the air flow. Without the gap, there will probably be less condensation, but any moisture that gets behind the siding will be trapped there for a long time. I don't know the properties of a wall of ICF versus a sheathed wall with building wrap. Anyone got any good info either in favor of, or against using a drainage plane?

I put the Hardie right up against the Icf in my house. I built a garage in 06' and used Hardie right up against the house wrap and even wrapped my garage door openings with it. Everything's held up nice so far. Heck. I never even painted the garage door wrap and it's still as good as new.

If you fur it out I would think that you wouldn't get any condensation behind it, because the siding temp should stabilize to the air temp quicker. I would just hate to deal with all that furring and window details. I'm in so Illinois so its pretty wet and humid here too.