Month: August 2014

Second Stair Run

August 26, 2014 / / 1 Comment
First stringer

First stringer

With the first run of stairs done and the landing subfloor in place, the next step in the stair project is to build the second run from the landing up to the second floor. This went more smoothly than the first run, partly because I had done it before, partly because I knew going in that the landing wasn’t square, and mostly because it was a shorter run.

Sarah installing risers and treads

Sarah installing risers and treads

I used the laser level to establish distance from the beam and height to the last step. The joist above the beam forms the last step of the stairs, so the stringers rest against it. The stringers also straddle the edge of the landing so that the first step is far enough forward that when the second floor landing is built there will be enough head room. Since I also put down a 2×4 as a kick plate for the stringers, I wound up cutting a zig-zag pattern at the stringer bottoms. As before, I sistered 2x4s to the stringers for added strength, but because these stringers are only 9½” instead of 14″ thick, I had to cut the edge of the 2x4s back slightly to fit against the kick plate.

Tread and riser connection

Tread and riser connection

I cut the treads and risers slightly differently than the first run. I still cut the tongue and groove at the back of the tread so it locks into the riser, but rather than simply having the riser stick up ¼” high at the front and notch the leading edge of the tread, I used the same type of tongue and groove that I used at the back, so the tread actually locks onto the top of the riser. Not only does this fit more snugly, I didn’t have to swap blades on my dado and cut different sizes. In hindsight I should have done that for the first run, but it’s fine. Sarah glued and screwed the risers and treads into place, so all that’s left is to open up the doorway at the top of the stairs and add a temporary railing and door.

Landing Subfloor

August 21, 2014 / / 1 Comment

Normally I wouldn’t dedicate a whole post to a little section of subfloor, but the landing turned out to be a bit involved. When I started building the and fitting the stringers I realized that the landing was wonky. It was ¼” too tall and it wasn’t square. To compensate for being too tall, I decided to use half-inch plywood subfloor instead of ¾” OSB. However, ½” is pretty thin for subfloor, so I devised a scheme for fitting sections of ¾” OSB in between the framing members, glued to the underside of the plywood (and to the framing) to add strength and thickness.

Test fitting OSB

Test fitting OSB

If the landing had not been out of square, this would have been pretty straightforward: just cut some rectangles to fit and done deal. However, given the out of squareness, everything was parallelograms. I’ve learned not to measure things any more than I have to. Measuring introduces more inaccuracy than it eliminates. Instead I put the OSB on top of the opening (generally lining up one edge) and drew the shape from below. Then I cut it out along the lines with the circular saw and fit it into place.

It worked fairly well, though I discovered after I had glued and screwed down the plywood (though thankfully not before it had dried) that one piece that fit between the stair stringers would not fit in from below because I sistered 2x4s to the stringers. I had to unscrew the corner of the plywood on top and slide it in (actually I had to do this three times because it kept falling through). Finally, once everything was in place and the glue was setting, I put in about 7,000 screws.

Landing subfloor installed

Landing subfloor installed

In one section the OSB was squeaking when I walked on the landing. I considered that it might go away once the glue set, but rather than take the chance I used a long 2×4 to press the underside of the OSB up against the subfloor and tightened all the screws. I left it that way until the glue set and now it’s all feeling solid and squeak-free. With this done I can work on the second run of stairs up to the second floor.

Risers and Treads

August 20, 2014 / / 2 Comments
Grooved riser (with glue)

Grooved riser (with glue)

It’s time for something more positive. This part of the stair project went extremely well. In fact, the only thing I had a problem with was the glue getting everywhere, including on my screw gun. The plan is to eventually clad the OSB risers and treads with hardwood, so there the OSB tread has no nose and it didn’t need to be as thick as a typical tread. Maybe I could have overbuilt it, but I already had a lot of leftover ¾” OSB from the subfloor so I used that. I didn’t want the treads to deflect, or flex at the back when you step on them, so I decided to cut a groove in the risers and a tongue on the treads so they’d lock together. I contemplated using the router, but instead I picked up a dado blade set for the table saw, which is awesome.

Riser and tread interlock

Riser and tread interlock

I first cut all of my treads and risers to width on the table saw with the regular blade, then cut them to length on the miter saw. Then I swapped in the dado blade and cut a ⅜” deep groove in the risers, ⅜” from the bottom edge. Next I cut out the bottom ⅜” of the edge of the treads, again ⅜” wide. The two pieces fit together like a glove. I wasn’t quite done though. I also cut out the bottom ¼” of the treads, ¾” wide, and cut all of my risers ¼” tall. As a result, both the front and the back of the tread locked into place.

Treads and risers installed

Treads and risers installed

With my careful stringer work completed, gluing and screwing down the risers and treads was a fairly quick job. Every once in a while, something goes to plan, and I’m pretty freaking happy about it. Next step is the landing floor.

Stair Stringer Struggles

August 12, 2014 / / 0 Comments

Our stair stringers were delivered and I set to work building the first run up to the landing. We’re using 14″ LSL stringers up to the landing because it has to span ten feet above the basement stairs. The stairs will be 42″ wide so there are three stringers, all notch cut. I considered doing an enclosed stringer, but I wanted the treads exposed on the side so we can have a wooden railing with iron balisters, plus the center stringer has to be notch cut anyway, so for consistency I notched all three. I also reinforced with a 2×4 glued and screwed to each one, per manufacturer recommendations.

Stringers installed

Stringers installed

 

I used stair gauges on a carpenters square to mark the cuts. All of my cuts were exactly accurate the first time, the stringers fit in place precisely the way they were supposed to, and they were perfectly level and aligned with one another. The only reason it took me three weeks is because I was admiring how flawless it all was. Eh heh, heh, ugh. No. As I continue to discover, I am not a very good carpenter. I made systemic mistakes, had flaws in my original plan, and spent most of the last few weeks trimming and shimming until the stringers approached a semblance of what I originally had in mind.

Let me run down the, uh, opportunities for improvement I encountered. Firstly, my original model had a flaw that in retrospect to everything else wound up being fairly minor. I made several important measurements that accidentally included the thickness of the risers and treads. In the end I had to make some field adjustments. I also had to slope the back of one of the stringers because the landing is slightly crooked at one end. I almost managed to cut one of the stringers nearly two feet shorter than the others, but fortunately realized my mistake before I had caused catastrophic damage.

The more major issue I didn’t actually figure out until I had been scratching my head at the stringers for a week, trying to figure out why the backs of each step weren’t in line. It turned out I had made the same mistake I’ve now made on multiple other occasions, which is forgetting that the house is totally wonky. The opening to the basement stairs is bordered by a doubled floor joist on one end. I used that edge as the basis for building the landing, and the landing as the basis for the stairs. As it turns out, that floor joist is not quite perpendicular to the outside wall, something I should have realized after all my subfloor frustrations.

Shim shimmery

Shim shimmery

As a result, the landing is not square (like, at all). I have built yet another parallelogram. When I carefully and exactly laid out the stairs to the landing so that the stringers fit, they were skewed to one another. I wound up cutting two of the stringers a bit shorter to compensate, barely fitting them against the landing without sticking down (one may be protruding by a sixteenth, but it’s close enough).

Even after that correction I wound up going back and forth, trimming and shimming an eighth here and there until my levels and measurements started to coalesce around the goal. I’m pretty sure upwards of eighty percent of the edges have had some form of adjustment. As it stands I still have a couple of steps that need some tweaking before they’re acceptable. It’s been a bit of a slog, to the point that I’ve re-written this post multiple times over the last few weeks as the situation evolved. The good news is that I didn’t ruin my expensive engineered lumber, the stairs will be as close to perfect as I know how to make them, and hopefully I’ve learned enough lessons that the remaining stair framing will go more smoothly.