Hello,
I am looking to buy a house with a lot of work that needs done. I am hoping to learn a lot from the experience so when I am living in it I can fix more myself rather than pay someone else to get it done. One of the first projects is going to be adding an internal staircase. The home used to be single family, but was converted a few owners ago to a duplex. When they did this they removed the stairs connecting the top and bottom floors. I plan to add that back in and make it single family again.
For the project itself, my step dad will be there to help install the stairs. But I don’t want to fully rely on him, even though he does know what he’s doing. We have done multiple, simple, project together before including installing multiple decks. The stairs for those were only 4-5 steps and pre-cut at Lowes though so I don’t think there is much to take away.
The plan is to install the stairs where the old staircase used to be as I think that will make the most sense, but if I am wrong about that please explain why so I can consider that when viewing the house this week.
What I would like to know is when I am at the house next is what should I look for, how do I calculate what all I will need, what I will need, and if there are any good sources online for this kind of project.
What should I look for:
I am pretty sure the best place to build the stairs is going to be where they already were, but what should I look for that will tell me there is a problem that will arise?
How do I calculate what all I will need and what I will need:
I know I need wood, screws and brackets. I am sure 2 boxes of screws will probably be enough, and a trip to the hardware store will be easy for that. Same with the brackets. But how do I calculate how much wood I will need? What size boards do I use for each component? Will I need anything else?
Are the any good sources online:
My step dad is really handy with this stuff and I know he isn’t going to let it get done wrong, but it’s a struggle planning stuff ahead with him. When I ask him what I will need, he gives answers like “it depends” or “a lot” but he doesn’t go into specifics. I would like to research a good bit on my own so when we do actually get together to do this he just needs to come over and help build it which is what he is great at.
I tried looking at YouTube and some google searches, but not much luck other than this wikihow (https://www.wikihow.com/Build-Stairs) which seems pretty comprehensive but I would like more than one article for a project this big. As for YT, it was videos on building prefab stairs and adding them to a home, or refinishing a current stairway, neither or which apply. If someone could supply a good website, or even a YouTube channel that I did not see I would greatly appreciate it.
Use the same place where the old flight of stairs used to be: the house’s structure and floor statics were calculated to have stairs there. You don’t want to mess with a house’s structure without the help of a statics engineer!
A little bit of “Stair maths” to start. Sorry for metric units, you might have to convert them if you’re in the US.
The ideal stair has an angle of 30°, a rise of 17 centimetres up, from step to step, with steps 29 cm deep, from front to back. Two rises plus one depth should be as close as possible to 63 cm because of the length of a human’s step.
You won’t get this ideal in most cases, because the distance between the upper and lower floor will rarely be an exact mulitiple of 17 cm.
1: measure this distance, finished upper floor to finished lower floor. Divide by 17 cm. Round up or down to get the number of steps you need.
2: Divide the distance between the floors by the number of steps from above
3: Use the “2 rises plus 1 depth = 63 cm” to determine the ideal depth. Stay as close to that as possible to make the stairs easy, safe and comfortable to walk on. It’s a good idea to make a drawing to scale at this point, to see how the stairs fit in the floorplan.
4: Now you can calculate the length of the stairs using good old Pythagoras (a^2 + b^2 = c^2, “a” being the distance between the floors, “b” is the depth of one step multiplied by the number - from above, “c” is the length of the stair - and the boards (“stringers”) on either side as well as the handrails).
Now you can calculate the material you need. Two stringer boards, the required number of steps of the correct length, plus brackets and screws on either sude of each, plus one or two handrails plus balusters.
In addition to these general guidelines, there are likely specific building codes in your area for minimum dimensions of stairs. Plenty of homes have non-compliant stairs, but it’ll save you a lot of hassle in the long run if you do things to code.
Definitely gonna save this for later. Having the formulas laid out like that is nice. Plus, what you said lines up pretty well with the wikihow linked above. While that isn’t the best source for confirmation, it makes me comfortable knowing that multiple sources came to the same methodology.