Shop-Built Housed-Stringer Stairs
Building in the shop makes assembly easier on the carpenter
Synopsis: Carpenter Andy Engel gives in-depth instructions for building housed-stringer stairs, beginning with laying out the stringers, then building the template for routing mortises in the stringers, positioning the template and routing the stringers, setting the treads, assembling and trimming the risers, and finally adding cove molding. The article includes details for special treatment of the top tread and riser at the upper-floor landing, in-depth drawings that showcase stringer layout, and a sidebar on determining riser height, tread depth, nosings, and stair width according to code requirements.
Forgive the pun, but housed-stringer stairs are a step up from standard notched-stringer stairs. Not only are they stronger and less likely to squeak, they’re essentially finished as soon as they’re assembled.
Housed-stringer stairs rely on mortises cut in the stringers to support the treads and risers. The backsides of these mortises taper, and wedges that match the taper are glued and driven in to lock the stairs into a cohesive unit. From the topside, the assembly looks like it grew together.
I usually build housed-stringer stairs in the comfort of my shop, where I can assemble them on a pair of sawhorses. With the stringers oriented face down at about waist height, it’s easy to control glue drips, and everything is reachable from a standing position. When assembling the same stairs in place on site, I have to work from below, which is especially uncomfortable for the lower treads and risers, and it’s usually not long before I’m spattered in glue drips.
The keys to the process are a simple router template and a bearing- guided bit. You can make the template, and the 3⁄4-in. pattern router bit is commonly available.
I usually use 5/4×10 stock for the stringers, but 2x material also works. When I lay…