Hello and basement question

[MidwestEric]

Hello there, Eric here.  The work the members on this site do is very inspiring. Being a total novice, I hope to get something half as nice of what I see here put together. I am planning on putting up the 20x30 1 story and stretching it out to 20x34. Maybe even 22x34. Not sure how to pull off that width increase yet. I read a post or two about using floor trusses to go that width. I supposed the engineered joists are another alternative.

I want to put in a full basement, and have read posts about increasing the block height to accommodate.  I'll probably go with formed and poured walls, so I am not to concerned about figuring out how to do that.

Right now, I think I need some help on stairs going into the basement to decide on engineered floor supports or conventional framing.  I have searched the site, but all the internal stairs I find are for going to up to a 1 1/2 story loft.  I did find stairs to a basement, but they were external to the building. I am looking for internal basement stair examples.  The problem is allowing for enough headroom without taking up too much floor space.  This is in a building code area.

Compounding that are any required mid-span supports you might fight against to keep the necessary head room.

Here you can see the stairs directly across from the front door (hopefully this works):



I am concerned how to frame this up, and if any mid-span supports are needed.  Really looking to see what what others have done and get feedback on the plan in general. 

Thanks

[Alan Gage]

Stairs eating up floor space is tough to get around. I don't know how many plans I drew up and revised last winter trying to get around that. It was compounded by the fact that that basement would likely be a work shop and I do some canoe building so I needed a straight run of stairs lined up with an outside door. The plan I was happiest with turned out to be a split foyer. That also meant less to excavate for the basement since more of the basement would be above grade.

Start reading up on stair design and figure out what code requires for clearance. Then start figuring how how much rise and run you have in your stairs and at what point you have the required headroom. That's how much floor space you're going to lose, not many ways around it. Get some graph paper and start sketching out lots of plans. It will start to make sense.

In the end I ditched the basement all together and went with a slab. I'm happy with the choice. Sure saved some time and money.

Alan

[walkabout]

Welcome MidwistEric,
I too spend many a sleepless night thinking about how I was going to get stairs to my crawlspace/basement to fit into my floor plan without sacrificing too much floor space.
I looked at U-shaped stairs (landing in the middle), but found that they took up too much space. I looked at spiral stairs and ruled those out as they restrict what can or can't be carried down the stairs.
We looked at external storm doors, but decided that would cut the basement off too much and make the space unusable.

Unfortunately my township would not allow a full basement in our cabin and said that I could go with 6'6" crawlspace. This did however benefit me somewhat as it now meant that the stairs did not have to meet code as they lead to a crawlspace and not a basement.
I ended up going with a winder stair and was able to meet all of the codes except the 6'8" headroom and the 6" minimum width of the winder at its narrowest point.
I tried designing the stairs in different locations, but ultimately chose to use the internal bedroom wall (from the standard plans from this site).
Here is my floor plan:


and the stairs:


For further pictures of the stairs you can check out my thread (in my signature).

[Danfish]

There appears to be little workaround the floor space requirements of standard code approved stairs.  If you can live with the access limitations, a spiral stair takes up less floor space.

Noted on your plan that there is a door proposed into the bathroom off the kitchen.  Most designers do not recommend this for both perception and sanitary reasons.

[MidwestEric]

Danfish - thanks for commenting on that bathroom. Seemed OK as we are using a camper now, and everything is really crammed in the camper. I do think your comment really goes toward long term if we ever sold. It could be a turn off to some people.

Walkabout - I really appreciate seeing your example. Nice work. I am wondering now that you have everything in place, what you think about the amount of room that staircase takes up.  Does it really get in the way? Maybe a larger bedroom or maybe more closet are some things I think of and skip a basement. I believe in your build postings you talked about storms making the basement a personal requirement. What do you think now that things are wrapping up?

Thank

[walkabout]

Your Qs:
Q1 what you think about the amount of room that staircase takes up.  Does it really get in the way?
A: i believe the configuration we settled with was the best use of space. The stairs do take up about 35 sqft in our already small main floor (20x27), but we were willing to sacrifice the space to get internal access to our non-livable  crawlspace.
I really can't say for sure whether it gets in the way as we are not using the cabin. I can tell you in a few months.

Q2: would I skip the basement?
A: even though the crawlspace is not meant to be livable, it can still be usable. But the main reason I say to keep it for us has been the safety it hopefully will provide in a storm.

What you will find is that it will be difficult to design code compliant stairs without taking up what seems like a lot of space. With a full basement (say 8' ceilings), 2x10 floor joists you are looking at approx 9' basement floor to main floor height, which equates to approx 14 risers(7.5") and 13 treads of at least 10", which means a straight stair without a landing would take up approx 11'. Add a landing of 3' and you are talking 42 sqft. For me the issue was not the sqft, but finding a location for the stairs that did not make the living room/kitchen too narrow.

[Don_P]

To make that set of winders pass inspection would require a bit more room on each of the winder treads, they are not quite that tight by code, min 6" wide at the narrow side.

I joists could span 22' in 14" depth. If the basement is 96"and the finish floor above is 3/4 the floor to floor height is around 110-3/4". with 15 risers the rise would be about 7-3/8". if the treads are 10" the run is 140".

you need 6'8" headroom, 80" plus the floor is 14-3/4" thick. the end header of the stairwell has to be at a point where the steps are at least 94-3/4" below the finished floor. 94.75/7.383"per rise=12.83, or 13 risers, 12 treads@10"... the hole for a straight run needs to be at least ~122"

[SouthernTier]

This brings up a question.  I will be getting my plans for my full cabin up here on the forum for discussion sometime soon now that my shed is done.  Construction is still a few years away, though.  It will have a half-basement and half crawl space, since it will be located on a hillside.

The basement part will be a walk-out, again, because of the slope.  I was going to have the only access to the basement through the walk-out door.  No stairways from the main floor above.  Hey, it's a cabin.

I've read the code book pretty thoroughly, and I haven't seen anything that says you have to have a stairway.  I suppose it depends on the actual building inspector, but do you think this would be a problem when the plans are reviewed?  It will be a small cabin (22 x 26, yeah, odd sizes, but wait until I post it up to explain), so having room for a stairway would be impractical.

[MidwestEric]

I was going to have the only access to the basement through the walk-out door.  No stairways from the main floor above.

That is a creative solution! I think as long as you have egress points on the 1st floor and basement it makes sense it would pass code.  I honestly don't know, but think you should ask you building dept. for a final word. Maybe someone else here has tried that before.  I could possibly see them treat it as a separate living space and require a bathroom, kitchen, and such, but I don't know.