Replacing a Basement Door
Mike Guertin demonstrates the steps for preparing, installing, and flashing long-lasting bulkhead doors.
Synopsis: Replacing bulkhead basement doors means disassembling and removing the old doors and installing the new, but the foundation and wall must be prepped properly for a well-functioning assembly. This article walks through the steps, including addressing any deficiencies in the foundation, preparing the wall for the new door-frame header, and flashing and finishing the new-door installation.
On this house, the existing basement bulkhead door was its second. The original was made from wood and became too difficult for the elderly owners to lift, so they had this steel one with torsion springs installed in the 1960s. But after 50-plus years of service—and several poor paint jobs—it had rusted through in a few spots and was peeling constantly.
It’s not a surprising situation. Sloped basement doors receive a lot of punishment. Children play on them, owners walk on them to reach the wall above, and they’re exposed to the elements. They’re also close to the ground and prone to damage from lawn equipment such as grass trimmers. Whether site-built out of wood, or manufactured from steel or plastic, they can deteriorate to the point where replacement makes more sense than a repair.
Out with the old
Basement doors are most easily removed piece by piece, just as they’re assembled. The doors and hardware come off first, then the frame is disassembled and removed in parts.
Assemble the new door
To make assembly easier, I unbox the new door components and preassemble them on a flat surface rather than try to do it in place on the foundation.
Prepare the Foundation
With the old door removed, this is the chance to address any deficiencies in the concrete foundation. Here, the previous installer had put sloped mortar around the metal door to keep out water, but it actually held water against the steel and led to corrosion, so it needed to be chiseled and ground away.
Prepare the wall
The new door-frame header and walls need a flat surface to seal against. This means some adjustments may need to be made when the wall sheathing and underlying framing is on a different plane than the exposed foundation wall below. The wall sheathing can be cut back if it’s proud of the foundation wall, or pressure-treated furring strips can be installed over the foundation wall to pad it flush with the sheathing above.
Cap the foundation
For a clean, finished appearance, cut and install metal accessory plates over the top of the old foundation walls. Like the door unit, these foundation plates are powder-coated on all sides.
Install The Frame
The most accurate way to locate the mounting holes for the door is to set the door in place, and get it plumb and square.
Flash and Finish
With the door in place, complete the installation by flashing the unit to prevent water entry, and installing or replacing the siding.
Patch the siding. Install new shingles above and around the door frame and flange, leaving a 1⁄4-in. space above the header as a capillary break.
From FineHomebuilding #294
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Mike Guertin (@mike_guertin) is editorial advisor.
Photos by Colin Russell.