Wonky Door Sill + Zip Edge
Cherub
| Posted in General Questions on
Ok two questions. Zip is supposed to be 2″ from masonry. What goes in that gap? This feels like a basic question but somehow I haven’t seen anything about it.
Second question. How would you build out this sill?
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Yes, and it appears that the lower edge of the sheathing is already swelling. It's not just Zip; concrete should not be poured against any type of framing unless it's an assembly designed for that situation. In most cases, the foundation should jog up to protect the framing at locations like the one you show.
On a renovation/repair like yours appears to be, options can be limited. The answer will depend on the answers to several questions:
Is there a roof above this door, and if so, what size, and what height above the door?
How often does this door experience wind-blown rain, or snow extending above the sheathing?
What is the foundation system? Is it dry? Insulated? If so, with what?
What will your cladding be? Will you have a rainscreen?
What type of door do you plan to install?
There may be more, but those are the first that come to mind.
Thanks Michael! So, yes, this is a renovation. The foundation is an open crawlspace with brick piers.
There's minimal roof overhang. I'll add an awning to this door once the trim is in place. Snow's no issue but wind-blown rain definitely is. I'm adding a rainscreen to the building, which is part of why this complicated. I'm not sure how to adjust the door casing for that. The cladding will be hardie plank on 3/4 inch battens. I'm keeping the current door. I'm not sure what type it is.
For context, that green concrete is the top of some stairs. Should I attach some metal flashing to the areas closest to the wood? What kind of moisture barrier makes sense here?
And should I flash under the 2" air barrier between the zip and concrete? Or should I add some trim? Or something else? I'm really not sure what to do with that space.
The best approach would be to demolish and start over with your steps, but assuming you don't want to do that, I would use an impervious material such as Ice and Water Shield (bitumen applied to a sheet of polyethylene) or sheet metal to fully separate the concrete steps from the framing or sheathing. It won't be easy with the concrete poured that close to the house, but it's important to create a separation.
With that impervious layer, it will be important for the part below floor level to be able to dry to the interior of the crawl space.
If you were to just add flashing, the sheathing would still be exposed to the dampness the steps create, and the sheathing would rot out in short order.
You need to create a continuous, flat sheathing layer all around your door opening. Then you can install the door conventionally, or push it out on bucks to account for the rainscreen gap. I would use a synthetic trim such as Aker, Azek or TruExterior to keep it from rotting.