Safe to Install a Door Flush with an ICF Wall?
atburi
| Posted in Energy Efficiency and Durability on
Hi everyone,
I’m looking for advice on whether it’s structurally safe to install our main entrance door (with sidelight) flush with the exterior edge of our ICF foundation wall. Here’s the situation:
– The door/window unit is 8’ tall and 5’ wide, and the door slab is solid wood.
– The ICF wall includes 2 5/8” of outer EPS insulation plus 1/2” of plywood sheathing, leaving only 3/4” of the door bearing directly on the concrete core.
– The unit will sit on a 3/4” piece of plywood secured atop the ICF wall, primarily to adjust the height and potentially add some strength.
I’m concerned about whether the door will remain stable over time with only 3/4” of bearing on the concrete. Some people I’ve consulted say it’s fine to install flush with the exterior edge, as long as there’s some bearing on the concrete and fasteners are used to support the weight. However, others—including the door supplier—suggest that at least 50% of the unit’s weight should be supported by the concrete core to avoid movement or sagging.
From a design perspective, installing the door flush with the exterior simplifies the transition from the door threshold to the exterior concrete pad. Moving the door inward would require a custom threshold extension to cover the exposed EPS foam. Another option could be cutting away the exterior EPS foam in front of the door and installing the unit entirely on the concrete core, which would allow the concrete pad to be poured directly against the door threshold while retaining structural stability.
Given these factors, does installing flush with the exterior edge provide enough structural stability, or would moving the door inward or modifying the installation approach be a better solution?
Appreciate feedback on best practices or recommendations based on similar installations. Thanks in advance!
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Replies
Is it standard framing on top of the icf or is the whole wall icf? I would be more concerned with side anchorage but you are not providing a lot of variables. Ie how heavy is the door and sidelites? How does it anchor? I would probably default to the door manufacturer as if you have issues even if they are not caused by the icf they will blame it on that.
You could cut away the insulation under the door and install a wood buck to support it though. I would be most concerned about side attachment.
Thanks, Freyr. A few more details:
- Double-stud framing atop the ICF (2x6 & 2x4)
- Fully-threaded Dresselhaus screws around door jamb and header; 12 ga strap ties around sidelight jamb and header
- Strangely enough, I don't have a weight on the door, unfortunately.
I think I would be inclined to supporting it, especially with the sidelites. if your icf already has plywood sheathing adding an additional support under it shouldn't modify your detailing much anyways, and the loss due to reduced R value is so minimal I don't think I would worry about it. Use pressure treated wood fastened to the concrete would be my vote.
If it had no sidelights and the door hinged of the framing I wouldn't worry about it as most of the door load would transfer to the framing, and you would only have to worry about threshold traffic. But since it has the sidelights you might get a bit of deformation at the mull post.
Thanks. I think that's the right approach. Installing the door today — wish me luck.