Drip Edge solution?

[VietGnome]

Due to insulation from slab, and variance in the slab I'm going to need to come out 2" in some places, and 4" in others. Is my best bet to just size for the largest and run a 4" wide Z-trim the whole way around the building?

If thats the case should I have the bottom trim angle back towards the building so it can seal against any variance?

Or should I be custom fitting?

 

[mm08822]

Not sure how much is bowed out to 4" but if minimal, consider varying the foam panel thickness. Or plan it all for 4" and add more foam at the 2" locations. (You would be varying the innermost thicknesses to ensure the visible final foam board is looking uniform.)

What will cover the exposed foamboard?

 

[VietGnome]

Not sure how much is bowed out to 4" but if minimal, consider varying the foam panel thickness. Or plan it all for 4" and add more foam at the 2" locations. (You would be varying the innermost thicknesses to ensure the visible final foam board is looking uniform.)

What will cover the exposed foamboard?

The exposed foam will be covered in cement board and either sealed and painted or parged/stucco.

Not quite sure get what you mean by trim the foam? You mean thin an entire sheet?

I can post photos in the day light but its varying from 2-4" over a 25ft span

Other sections and walls have a maybe 0.5-1" variance.

 

[mm08822]

The exposed foam will be covered in cement board and either sealed and painted or parged/stucco.

Not quite sure get what you mean by trim the foam? You mean thin an entire sheet?

I can post photos in the day light but its varying from 2-4" over a 25ft span

Other sections and walls have a maybe 0.5-1" variance.

Not trimming the thickness. Buy 1/2, 3/4, 1" and build up the gap to get the 4" or whatever overall "thickness" works for the variation.

Let's say you want/need 2" of foam all the way around. Where the wall is not bowed, add 4" foam. Where the wall is bowed out 2", you only add 2" foam.
Assuming the wall was placed straight (not following the bow), attach 4" z channel to the sheathing. As you then look down the covered foundation wall, it now looks straight(no bow detected).

Are all 4 sides bowed?

 

[VietGnome]

Not trimming the thickness. Buy 1/2, 3/4, 1" and build up the gap to get the 4" or whatever overall "thickness" works for the variation.

Let's say you want/need 2" of foam all the way around. Where the wall is not bowed, add 4" foam. Where the wall is bowed out 2", you only add 2" foam.
Assuming the wall was placed straight (not following the bow), attach 4" z channel to the sheathing. As you then look down the covered foundation wall, it now looks straight(no bow detected).

Are all 4 sides bowed?

I see what you're saying.
Really 3 have bows, but only 2 are really noticeable.

Walls are straight. Is it fine if the Z doesn't fit snug to the insulation?

 

[mm08822]

I see what you're saying.
Really 3 have bows, but only 2 are really noticeable.

Walls are straight. Is it fine if the Z doesn't fit snug to the insulation?

Maybe overbend 10 degrees and see how that works along the entire length of the wall.

What's your dog's breed?

 

[Prospecter]

Mice will be determined to get to the foam. Overbend the Z to get a good seal.

 

[Fav Onefour]

I see what you're saying.
Really 3 have bows, but only 2 are really noticeable.

Walls are straight. Is it fine if the Z doesn't fit snug to the insulation?

What is causing the bow?
If it's just a small area you could trim the backside on your foam panel so it's tight. You will have the best luck of success over time with foam tight to the foundation. It would look better too. I think is looks sloppy if the foam wanders in thickness.

 

[tarmy]

Maybe for the whole wall out an add thinner foam insulation up there too. That way the exterior looks clean, drains well and solves both problems. I just went thru this same issue last year

 

[VietGnome]

What is causing the bow?
If it's just a small area you could trim the backside on your foam panel so it's tight. You will have the best luck of success over time with foam tight to the foundation. It would look better too. I think is looks sloppy if the foam wanders in thickness.

Concrete forms started to bow. The foam fits tight to the wall, but the wall itself slightly bows. Photo attached. They are kinda **** but basically shows some sill plates are flush to the edge, other are inset more

 

[alwaysFlOoReD]

I think I would belt sand the high spots down .5" to .75" and go with it. Only you and a pro will ever see any bow.
Also I've custom bent aluminum flashings to hide exactly what you're seeing.

Concrete forms started to bow. The foam fits tight to the wall, but the wall itself slightly bows. Photo attached. They are kinda **** but basically shows some sill plates are flush to the edge, other are inset more

 

[VietGnome]

I think I would belt sand the high spots down .5" to .75" and go with it. Only you and a pro will ever see any bow.
Also I've custom bent aluminum flashings to hide exactly what you're seeing.

Belt sand what exactly?

What was your flashing solution? I can get coilstock and have it bent.

 

[VietGnome]

Maybe for the whole wall out an add thinner foam insulation up there too. That way the exterior looks clean, drains well and solves both problems. I just went thru this same issue last year

Unfortunately the size of the building would cost a small fortune.

 

[alwaysFlOoReD]

Belt sand what exactly?

What was your flashing solution? I can get coilstock and have it bent.

In the last pic you posted before I answered, there is a bulge easily seen on the insulation. I would belt sand that bulge but no more than .75". Straighten as best as you can without compromising the r-value too much.
And as far as the flashing, thinking back on it that was a wall that had the bulge, not the foundation, so that idea won't work.

 

[racecougar]

Belt sand what exactly?

The foam board.

 

[VietGnome]

In the last pic you posted before I answered, there is a bulge easily seen on the insulation. I would belt sand that bulge but no more than .75". Straighten as best as you can without compromising the r-value too much.
And as far as the flashing, thinking back on it that was a wall that had the bulge, not the foundation, so that idea won't work.

The foam board.

Ah thanks! I see what you mean. I can likely sand it down to make it more level for sure.

 

[mm08822]

As I said in post 4, buy some different thicknesses of foam board. Forget sanding.

Put a thinner board(s) on first over the high spot. Finish up with 1" or 2" on the outer surface.
If concrete bulged 2", you only put on 2" foam total thickness.
If bulged 1", you put on 3" foam total thickness.
If bulged 3" put on only 1" thickness.

You are making the first layer thickness vary so it provides a flat plane for the final board to attach to.

 

[WildBill]

I had the exact same issue on my shop and used a cheap harbor freight hot knife to cut the top 8" inches or so of foam down where needed to get it close. The rest of the foam was getting back filled so it didn't matter that it stuck out. But building up layers would probably be better, mine was already partially buried so that would have been really difficult.

 

[VietGnome]

I had the exact same issue on my shop and used a cheap harbor freight hot knife to cut the top 8" inches or so of foam down where needed to get it close. The rest of the foam was getting back filled so it didn't matter that it stuck out. But building up layers would probably be better, mine was already partially buried so that would have been really difficult.

These photos are already backfilled. Framing is sitting ontop of an 8" knee wall.

I could cut it, the plans called for all the insulation to be below grade, but I want going to complain, or willing to uninsulate my knee wall.

 

[Copymutt]

The exposed foam will be covered in cement board and either sealed and painted or parged/stucco.

Not quite sure get what you mean by trim the foam? You mean thin an entire sheet?

I can post photos in the day light but its varying from 2-4" over a 25ft span

Other sections and walls have a maybe 0.5-1" variance.

Cement board ie Hardie Plank/ board is not spec. for ground contact. That said, mine is fine, been covering the foam for 15 years.