Wrap-around-stairs

Jaketoo

I am going to build a 48" wide x 42" deep landing (2"x10" framing), outside an entry door on the back of a house. The landing will be about 28" off the ground. It will have stairs (3 treads) that wrap around the 3 sides of the landing (4th side attached to house). I figure I will cut and install all the common stringers (tacking the corner ones in case I want to slide them back and forth). Then I will probably try to fit an outside corner (hip?) stringer in with only the top plumb cut and bottom seat cut. I will probably use a level across the common stringers (2"x12"s) to make some marks on the outside corner stringer. I'm not sure if I will double up these outside corner stringers. Either way the risers cuts will need 45 degree bevels. The decking will be 1"x4" fir. The risers will be PVC board. Any tips on how to mark and cut the outside stringers?

pkp

there is two ways to do it.
(way one) Build your commons the normal way with your framing square, then build your hips with the same rise and with a run that is the ratio 12x16.3125 For example, if your rise was 6.5 inches and your run was 12 inches then for the hips, your rise would stay 6.5 inches and your run would become 16 5/16 of an inch.

(way two) Aka the cheater way just build progressively smaller platforms. If you are only doing 3 steps I think I would do it this way because not only is it less math, I bet it would be less work than trying to make jack-stringers intersect with your hip stringer properly. Not to mention you will be loosing a good deal of strength with such a big bite out of your hips. you will be shoring then up just as much as if you had build platforms anyway.

Jaketoo

Thanks for that great info! I framed the landing and cut all the common stringers today. I think I will build platforms as you suggested.

Joe Carola

What is the run on the common stringers, 9-3/4"? I assume you made the rise 7".

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Joe Carola

Jaketoo

Yes, the run is 9 3/4". The rise is 7 1/4". I was hoping to land the stairs on an existing concrete paver block patio, but yesterday I pulled up the pavers. I dug a trench around the perimeter of the new stairs, so I can pour a solid level footing to land the stairs on. The footing will be about 12"x12"x22'. I am going to cut hip stringers for the outside corners.
I will do 9.750 x 16.3125 for the runs as suggested. I am still not sure how this will work. Will this calculation give me long points? Then I cut 45 degree bevels on the risers? I will cut an inch or so away from the riser marks so I can put the stringer in place, and see how things match up.

Joe Carola

If your run is 9.75", then your hip run is 13.78858" or 13-13/16".

Whenever you have something like a hip running at 45°, then you can always multiply the run x the square root of 2, and that will be the run of your hip, or in your case your stringer hip.

All you have to do is draw on a piece of plywood or a 2x12 measure up from the corner on each end 9.75" and measure the diagonal and you'll see that you have 13-13/16". That will be the long points.

Here's a quick drawing that I did using two hip stringers. You will see how the 9-3/4" common stringer run creates a 13-13/16" hip run.

This is the reason why when framing a hip roof, you hold the square for example on a 5/12 pitch roof for the commons, you will hold the square on 5/17 for the hip plumbcut mark.

This is because if you draw a 12x12 square, when you measure the diagonal it's 16.97056" or 17" of run at 45°

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Joe Carola

pkp

I thought it was 16 5/16, not 16 15/16. I guess my memory failed me.
Good thing you were here to set us both straight.

Jaketoo

Hey I meant to thank you guys for the information on laying out hip stringers. That drawing was helpful. You saved me time and money. Here is a picture.

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neolitic

Looks like you put a lot of work into it, and I bet they'll be happy with the finish
I can never figure out though, why people don't want to use the same footprint, and get more stoop, and less step They can't even lean the ol' snow shovel next to the door
A tip, next time if you run a 2X6 low between those corner stringers? You can nail/screw farther back from the miters on the tread, reduce chances of split-out.

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(Sorry....it seems there really are dumb questions)

FrankT

Looks real nice.

Now just wait till the BO tells you he wants handrails on it.