Split level walls and floor joists - how are they constructed?

jrbutterfly

Hi, I am new to the site -
I searched all forums for topics on split level homes, and didn't find anything that addressed my questions.

In a split level house, is there a specific name for the walls that separate the two differing levels? For lack of a better term, I will refer to it here as the center-wall, since it is basically at the center of the house. It runs from the front exterior wall of the house to the stairwell, and another section from the rear exterior wall to the stairwell.

The house in question has essentially 4 floors and an attic: ground level (1st floor) basement and garage, 2nd floor living room, dining room, and kitchen, 3rd floor 3 bedrooms and a bathroom, 4th floor master bedroom and bathroom. Attic sits on top 3rd floor, which sits on top of 1st floor; 4th floor sits above 2nd floor which sits above a 3' crawlspace.

The ceiling of the 2nd floor (the floor of the 4th floor), where it hits the center-wall, that is essentially halfway up the wall of the 3rd floor - can someone explain to me how that is accomplished? I want to know what I *should* find before I open anything up. It is my understanding that this center-wall is load-bearing, as I can tell from the nails in the wood flooring that the floor joists run perpendicular to the center-wall.

The reason I want to know is, currently the master bedroom has a closet against the center-wall, and inside the closet is an access panel to the attic, 51" off the floor. I want to put in a stairway so that I can walk up to the attic instead of climbing up into it.

I believe I have the basic concepts of stair construction down, except for figuring out how to support the stringers at the bottom and how to attach them at the top.

In my case, the stringers will be parallel to the floor joists of the 4th floor, and I can only assume there is some larger beam along the ends of the floor joists that they tie into, but I am not sure how thick it will be, and what I need to do if it is not wide enough to support the bottom of the stringers. I can't shift the stairs out into the room to fully sit on the existing floor, since I want to install a door flush with the center-wall with the stairs completely behind the door (it's okay with me if the first tread almost touches the back of the door though).

Also, how do I approach cutting into the joists of the attic floor for the new stairwell? They run parallel to the center-wall (ie, perpendicular to the staircase), so I am not sure if these joists bear any load from the roof or not... If not, do I just cut them off at the edge of the new stairwell, minus 1-1/2" and put a new board in to tie the ends together? If the upper end of my stairway does not end exactly at a joist, can I just add a short piece connected to these new side-rails to nail the top of the staircase to? Or should I alter the dimension of the stairs so that it definitely does butt up against an existing joist?

I really want this stairway to be sturdy enough for carrying heavy loads up it - next year's projects include a lot of re-construction of the two different roof sections, to put it in a nutshell they are horrible and need a lot of work both inside and out, so this stairway will make work up there a lot easier.

Thanks in advance!

jogr

Usually the floor joists and ceiling joists for a level run parallel to the walls that represent a transition from one level to the next. So the opposing walls that the joists sit on are of equal height.

The joists could run perpendicular to these "transition" walls if a band is attached to the wall at the correct height.

As far as your stair I wouldn't assume that there would be a beam there. You really need to look at it and see.

I don't understand what kind of "reconstruction" access you are hoping to get with a short 51" high stairway. You would only be able to get small things up there. I also don't understand why you would want to bring materials into the attic from the inside of the house for roof reconstruction. You would normally do that from the outside. Rip off the old, fix, recover.

If you need to cut off a joist for the attic opening that is usually done by doubling the remaining joists on both sides of the opening and putting a double header at each end of the opening (the cut off joist is attached to this header). But before doing this you need to make sure what loads the joists are carrying.

jrbutterfly

Thanks for the info!

Transition wall sounds like a much better description of what I was describing.

One of the major reasons for the staircase is to use the attic for out-of-season storage. Right now, the master bedroom is very poorly insulated, so we have to have a small heater in there on winter nights, and a gigantic window A/C unit to keep it comfortable in summer. The A/C unit is so wide that it "just" fits through the attic access, therefore, john can't lift it up and shove it in with his arms wrapped around the sides (which is the only way he could lift it to the required 51" height) - instead, it takes the two of us to lift it from underneath, so no fingers get pinched in the doorway - and I end up dropping to my knees, A/C unit above my head, supporting the back edge till he gets it to the edge of the attic opening, then I scoot out between his legs and he can finish shoving it into the attic. A real 3-ring circus, one of us is going to get hurt at some point. With a regular staircase, it would be much easier for him to just carry the A/C unit up to the attic.

The other reason to have easier access - I said the attic needed work inside AND outside. And measuring the accessible spaces from the inside is much easier than from the outside, so that I can work on rough drawings of ideas for what we should do, and how much materials we will need, cost, etc....

Revamping the insulation work is going to be a part of next year's project lineup.

To expand on what I mentioned before, the roof is a mess -
Above the 3rd floor, where I can actually stand up in the attic, the roof slopes down on both sides at a certain slope (I haven't gotten the measurements to tell you what that slope is). Now, on the section of roof over the 4th floor, the roof is more sharply pitched. It essentially goes all the way down to meet the top of the 2nd floor - ie, the gutter on that roof is right above the front door leading into the living room, below this bedroom. Same on the rear. On the rear of the house also, on this level, the master bathroom (what a joke, it is TINY), has its own separate roof pitch, kind of a like a dormer but not with a peak, just a differently-sloped roof section. Not as sharp at the bedroom ceiling, but somewhere in between that and the pitch on the other section of the house. Oh, and no exhaust fan, just an old steel-frame window that I had to make a kit-screen for so the cat wouldn't go out the window.

Big issues with headroom up there - john's side of the bed can only be in the center of the room, b/c Mr. 6'2" can't stand up under the crazy celiling on the sides of the room. At 5'6", I have to slightly duck to scoot down my side of the bed, which is only a foot and a half from the wall. In addition, the only place john can stand up straight in the bathroom is in the shower - immediately beyond the edge of the tub, the ceiling is sloping down and hitting him if he stands up in front of the toilet. Pretty annoying.

So we are toying around with ideas on re-constructing the roof, or putting in dormers, or something along those lines, to give us more full-height usable space in the bedroom and possibly the ability to enlarge the area of the bathroom.

All these areas, as I said before, are very poorly insulated - what I can see in between the attic floor joists looks like thick gray dust. there is absolutely nothing on the underside of the roof sheeting. I can see pink fiberglass batting-type insulation between the studs of the wedge-shaped transition walls at the attic level, but I have no idea what's actually in between the roof and the sheetrock ceiling of the bedroom.

So, if nothing else, we'd probably want a professional to come in and do a good insulating job, and that would be done from the inside, right?

The roof itself already has more than one layer of shingles, and is about 2-5 years away from being due for total re-roofing anyway. I took a look at the rafters, and I don't like what I see. I am sure this was standard back in the 50s when this house was built, but there is one ridge beam, it is two sections, since it extends through both roof sections, and two pieces of 2-by-x lumber were used to span that distance. However, the joint is not right over the transition area, it is maybe 3 feet away from there, it is NOT supported underneath of where they are butted against one another, and I see no other form of reinforcing, not even metal plates or brackets... there IS however a crazily leaning 4"x4" post sitting on the attic floor halfway across the 3rd-floor ceiling, as that part of roof looks like it had/has? a sagging problem... I don't know whether the post was installed at the crazy angle it is now, or whether it was straight and now the sagging roof pushed the support beam into tilting, or what. Am I crazy or does it seem like the roof should have better support than that?

All I do know is, I want to learn about what is there, and what the options are for correcting the various issues, we each have a father with 20+years construction experience, but they are up there in years, so our approach to projects is this: take measurements/pics/drawings to the dads, do research, get advice on what we can and can't do on our own, and go from there. But we have to know what's there first, and that requires getting into the attic, and climbing through that opening is a PITA.

Btw, now that I have detailed all the issues with that 4th floor and attic, does anyone have any suggestions for the best way to get more space up there? Dormers, raise the whole roof, or what? We are still looking for as much input on that as we can get. We are figuring that whatever we do, when the roof gets opened up for that is when we will address the rest of the insulation problem.