Hello. Shoyan here. I’m a Japanese carpenter. Last time, I installed the winder stairs. This time, I’ll make six straight stairs below and four straight stairs above them, making 14 steps to the second floor. I’ll do my best. First, I’ll mark the stringer boards. I’ll put the heartwood side facing out because I think it’s better to show heartwood as much as possible. In the case of pinewood, you can use either outer or inner surface outside. The wood won’t tear out. Japanese cypress and cedar are particularly prone to tear out during processing. Pinewood won’t tear out anyway, so when I want to use the heartwood portion as much as possible, I always use the heartwood side facing out. Fortunately, there are only a few knots on the stringer boards this time. There were a lot of knots last time, but there is only one this time, so it can be hidden easily. The tread width is 212 mm (8.34"), and the riser is 200 mm (7.87")high.
The seventh step will be the first winder step. I’ve finished marking six steps for the first stringer. Next, I’ll measure the diagonal length of the seventh step to the first step. To do this, I will compare the markings I drew on the site and the stringer’s length. After confirming the length is accurate, I’ll mark the whole stringer board. Whenever I mark the tread thickness, * .078″
I’ll make the width of the corresponding groove 2 mm* narrower. * .078″
If I don’t make it 2 mm* narrower, the tread will come loose because I’ll do kigoroshi* during installation. Before cutting the whole stringer board, I’ll only cut the two ends that will be joined.
Then, I’ll fit it temporarily. The whole stringer will be unusable if it doesn’t match up when temporarily fitted. That’s why I only cut the joints at both ends first. I know it’s a bit late to say, but there are three types of boards on stairs: stringers, treads, and risers. There are several names for these in Japanese. Stringer is the board that I’m cutting now. It’s a sideboard that supports the treads. I will chisel off the parts where the treads will be placed. It depends on the region of Japan, but the stringer is called “Oyaita” (parent board), and the tread is called “Koita” (child board) in Japanese. And the board at the back is called “Kegomiita” (riser board). These are the names we call them.
I’ll temporarily install the stringer that I only cut the joint part from. It won’t fit straight away, so I’ll keep cut away where it overlaps until it fits. I’ll also temporarily install the lower six steps. I’ll install furring strips (thin lumber) on the wall on the right. The left side will be the railing side. The plasterboard will be installed on the railing wall. So, if I install the stringer in the same way on both sides, the front of the stringers will become uneven. So, I’ll notch the left stringer 15 mm (.590″), which is a thickness of furring strips, so that it won’t overlap the column and fit inside it. Also, the tread will overlap the riser. I’ll measure that amount and cut the stringer diagonally. I’ll mark the position of the riser’s front to the tread while the stringers are temporarily fitted. Now, I’ll cut out the tread parts of the stringer. First, I’ll use a cutter to cut according to the marks. It’s easier to use a cutter rather than a chisel. I’ll use a groove cutter for rough cutting.
This can cause sections that are cut against the grain to tear out. I’ll make sure I use a different cutter for those parts to prevent this. *.393″
I’ll rough cut a little over 1 cm* deep using a groove cutter. When I use the groove cutter, I normally use it freehand. It’s advisable to use a guide ruler, but I’ve gotten used to this way of working, and it’s easier for me. As far as possible, I’ll make the shavings come off in the same direction. The shavings are resinous since the material is pinewood. They are difficult to remove even by vacuuming or sweeping. So, I’ll cut a groove while turning the material so that the wood shavings won’t scatter everywhere.
I’ll finish the groove for the tread with a striking chisel. When making a long groove like this, it’s better to use a striking chisel to cut out a large amount rather than a basic interior work chisel. You can chisel off a large piece in one go. Since I used the cutter earlier, positioning the chisel is easier. It’s as if there is a roadmap for the chisel. The basic chiseling position is to sit up straight or sit on the wood. It is dangerous to use a chisel in front of the wood while straddling it. Before tidying up, I’ll cut a groove for the wall material. This tool is called a “Koana cutter” (groove cutter). It can make grooves between 3 mm and 15 mm.*(.118″ and .590″) Only the 3mm (.118″) blade is set, but adjusting the angle can make a wider groove. Because of that, we also call it “Jizai cutter” (free cutter) Now, I’ve finished cutting the stringer. Before installing it, I’ll cut off the floorboard of the first step at the place where the riser will be inserted. After cutting the floorboard, I’ll screw the riser from the side.
For this, I’ll cut it perfectly straight now. I’ll finish the stringer and install it. I applied super-surfacer at the beginning. But the pencil mark is still there, so I’ll also use the hand plane to get rid of the mark. I don’t like planing the stringer, no matter how many times I do it. If I don’t pay attention carefully, my hand can get caught in the groove. *3.54″
I’ll secure the stringer now, using long 90 mm* screws. I’ll screw it in the direction of the three winder stairs I installed last time. Of course, I’ll screw it onto the floor at the bottom too. But other than that, I’ll screw it to the inside of the staircase so that the stringer attaches securely. Next, I’ll make ten treads.
I’ll rough cut ten pieces, then check the color and grade them to use the reddest ones at the bottom. First, I’ll cut a groove on the underside of each tread for the riser. I’ll cut it about 30 mm* (1.18″) from the front and about 1 cm (.393″) deep. I’ll make a “Bakabo” (stupid stick) to measure the length of a tread. This is a stick that even stupid people can use to measure. I’ll measure the actual length and mark it on the stick. I’ll use this stick to measure and cut the treads. I won’t cut from the front straight away when cutting a wide board like this. The saw blade could get caught or cause kickback. First, cut a third of the way in from the back, then cut as much as possible from the front by pushing slowly.
Next, I’ll make an anti-slip groove on the top of the tread. The blade is rounded, so the anti-slip groove will also be rounded. If the anti-slip groove’s start and end points have not been fixed, I need to check it from above and below and deciding where to stop is difficult. Since the blade is a bit dull, I’ll sand the treads slightly with sandpaper to remove the roughness. But rough surfaces may be better for anti-slip purposes. Finally, I’ll finish the treads. Of all the hand planing on the staircase, I like planing the treads best. It makes me feel like I’ve almost finished and can finally install the treads. As I said in the previous video, I’ll plane the treads back a little angled to properly fit the riser. I’ll chamfer widely at the end of the treads. It won’t chip when inserting the tread, and resistance will be reduced the more I chamfer it.
What do you think this is? It’s the shavings of wood that I chamfered. It’s all curly, and it’s adorable. Next, I’ll do kigoroshi. I’ll tap the edge gently so that it compresses evenly. Before installing the treads, I’ll set the tension rod on the left stringer only. This is just in case since there are only a few screws in at this point. Now, I’ll install the treads. This is just about the right amount of room for the treads. It would be difficult to install the treads if it was too tight, and if it was too loose, cutting grooves would be pointless.
This is the top part of the staircase. The riser for the 13th step can’t be screwed from the back because the large floor beam will overlap it. *.708″
So I’ll drill holes using an 18 mm* drill and then screw it in from there. The treadat the top of the stairs can’t be tapped in to install them from the back. So, I’ll remove the horizontal member temporarily. After that, I’ll move the left stringer out and install the top tread by tapping it from the side. This makes them easy to install.
Then, I’ll screw the horizontal member back in place. I’ll secure the left stringer once I’ve installed the top tread. I’ll secure the treads. First, screw from the back toward the front. Then, secure it with three or more long screws from the back. Finally, chisel the riser parts to correct any misalignment. This is the most unpleasant part of chiseling the staircase.
It looks easy to make it straight, but it isn’t. I’ll use the measuring stick Bakabo that I made earlier and make the risers. These are almost entirely white. So, I’ll just match the wood grain and decide where to use each piece. And I’ll only chamfer the top edge that will fit in the treads’ grooves. I’ll apply glue to the groove where the riser enters. And also apply it to the top of the riser. Place it firmly on top. *2.56″
The board is thin, but I’ll secure it with 65 mm* screws. I’ll use a thick drill to make pilot holes at the end of the top edge and screw them in. I was in a hurry to install the top riser, but there is something else I must do first. I’ll apply a lot of water to the part where I did kigoroshi. Wet the top and bottom edges evenly. By doing this, the part compressed by kigoroshi will expand and fit well. I’ll go back and install the second and the third risers. And finally, I will install the problematic riser.
This riser can’t be screwed on all four sides. So, I’ll attach three sides by gluing them. I’ll apply the glue evenly. I’ll then insert the riser and screw it temporarily to prevent it from falling out. The bottom holes are aligned with the tread. So, I can screw the riser to the tread using a long screwdriver bit. First, secure the riser firmly to the tread from the bottom holes. *.708″
I drilled the 18 mm * holes earlier to secure the top riser. I’ll make a plug to fill them.
*.708″
If the holes are 18 mm*, make the plug a little narrower *.551″
than 14 mm*, to make it a bit loose. I’ll measure the actual length of the hole carefully and cut the plug to this length. After applying glue to the end of the plug, I’ll screw it from the back toward the front. The riser will attach well to the stringer and the second floor’s stile. Finally, I’ll treat the risers to prevent cracking. I’ll apply a lot of wood glue to the edges. Wood glue is best for preventing cracks. I’ll also apply it to the middle of the grain to prevent cracks at the back. Unfortunately, there’s no way to prevent the front from cracking. This glue is white when applied, but after a day, it becomes transparent, which is a great feature of wood glue. I have now finished installing the staircase. Both the first and second halves took three days each, a total of a week. A staircase made from pinewood is gorgeous. A lifelong treasure for your home; it’s priceless. It becomes more beautiful the more you polish it. And here is the stairwell. It’s quite spacious.
That’s all for today. Thanks for watching!.