Ok, Bad planning on my part but when I put a full basement under the original plans for my cottage I was off by 4 inches in accomidating a UBC or BOCA styled Spiral staircase. 5 foot is the minimum diameter by that code
The Topic in question is when is a footing required? I’ll have to cut a 15 inch arc out of one of my main floor sistered floorjoists to allow the spiral staircase to fit. The center beam and the bearing wall are about equidistant from the cut (6 foot either way). There is no load other than living room floor.
In my mind the solution here is to put a couple of posts from the ends of the cut sister down to the basement floor. Nice metal posts with the jack screw at the end. I’ve currently got a crack free floor with a thick bed of gravel below at least 4 inches of concrete. I feel confident,… should I?
The only load these posts will carry are the dual 11-7/8″ I joist weight, The t&g 1-1/4″ glued & nailed subfloor and eventually the T&G hardwood floor.
So the nagging question is should I cut a hole in the 2 year old beautiful floor to muck arround and pour deeper concrete like a footing? This isn’t the main beam supporting the joists, it is just a joist.
Have fun!
Replies
You already know the right answer requires more work, more time, more money, and messing up your beautiful slab.
...that's not a mistake, it's rustic
I really don't think it needs a footing. In the spirit of load bearing (holds up a roof or a wall) there isn't any load.
Is there a quantitative (LB's or something) unit that defines the need for a footing? For example the base of a stairway to a basement has no footing beyond the slab. That is 3 times the weight of this that I have spread over two posts. So .. why does this need a footing?Jack of all trades and master of none - you got a problem with that?
Well, the title of your discussion got my attention!. If I understand your description, really, you are just trying to find someone to bless your hack... but I might do it on my own house in the interest of saving time/money/etc, but certainly not on someone elses. Probably, not on mine either, assuming I may want to sell it some day. Look at the attached pictures...
Matt
Nice pic's. Looks like Autocad but how did you convert it for this forum?
For some reason I haven't thought about placing additional sisters. You make a good point. That would be cleaner and avoid the posts. Although it would be a bit of a project (even extend the hack temporarily) the longer term view would be more secure.
The posts wouldn't be much of an issue for me because they wouldn't be near the entry/exit at the base of the stairs. Although the "adopted" sisters idea above is better, I still wonder about what defines the need for a footing.
Thanks for the idea. That should be in the back of my mind all day as I hear people babble about other things.
"bless your hack" I'm afraid that phrase will outlive all of us.Jack of all trades and master of none - you got a problem with that?
Nice pic's. Looks like Autocad but how did you convert it for this forum?
I have to re-ask this question. I've got AutoCad light 2000 and I can whip up a drawing pretty fast but the conversion tool doesn't seem to be standard in the software. Unless those are a "Save as" and .WMF (word Metafile) is what you created. It just gets messy.
What tool did you use?Jack of all trades and master of none - you got a problem with that?
I used another drawing tool called Visio. It saves drawings in a priporitory format, but you can do a "Save as" and I chose .gif, since most people's computer can view those with no problem.
You are right about the header needing to be double. I was assuming an LVL, but really, my best work is not done at 06:00AM (which this was).Matt
Just practicing.
Joe Carola
Booch, what sort of staircase is this? Could you build a curved wall on the backside of it between the posts, turning it into a loadbearing wall rather than two point loads?
Joe H
Wonderful Idea. The spiral is one of those pallet of part Ironshop type pole with sleeved stairs deals. Two flights. One from the basement to the main, one from the main floor to the loft.
A 2x4 wall with a curve of drywall or vertical wood paneling is worth consideration. It also spreads out the point load as well as kills part of the draft from the main floor down to the basement.Jack of all trades and master of none - you got a problem with that?
You have standard framing. There's no need for posts. Frame the staiwell like the attached drawing that Dirishinme drew for you but just add doubles where I put the arrows. Add double joist hangers and single joist hangers.
Joe Carola
You think I need double joists all the way around the opening? The sisters that replace the joist that should have gone thru the stairwell I understand. 4 joists bridged replace 3 in standard spacing. Since the length of the cripples are less than 7 foot it is hard to imagine a need for double thickness.
I'm not arguing, I'm trying to understand the physics of this setup.
Where the sisters originally were placed, seemed like enough strength the first time I built it. The floor feel was secure. The cripple supports (I'm probably wrong in the term but that is what it would be in a wall at a window opening) seemed strong enough to hold. Particularily since I filled the web of the I-joist with OSB glued and clinch nailed where the single joist hangers mounted.
I poured over the I joist documentation during the framing. I wanted to get the assembly right and curse the product not my own incompetence. As satisfying as solid lumber is to nail, trim, and admire as a finished product. After I got familiar with the Rube Goldberg rituals of assembly I began to admire the features of the I joist. The features I found were: weight (less), strength (more), and the consistancy of product (close to flawless). I still hate the hangers, goofy nails, glue and fillers in the web. I suppose a positive position power nailer would help change my opinion.
The above rambling is my way of whining I thought I did it right. All except the measurement thing. What was that, measure twice cut once?Jack of all trades and master of none - you got a problem with that?
You think I need double joists all the way around the opening? The sisters that replace the joist that should have gone thru the stairwell I understand. 4 joists bridged replace 3 in standard spacing. Since the length of the cripples are less than 7 foot it is hard to imagine a need for double thickness.
Yes you do. Any time you frame an opening like that you have to double all the way around and put in 4 double hangers, it's code around here anyway in NJ, it would never pass inspection. They even make us double around the framing for attic stairs. The small doubles are carrying the 7' joists. Any I-joists you use come with instructions and they will show you that, either you double up I-joists and fill in the web or you double up LVL's to head off any boxed opening, wether it's a stairwell, fireplace, plumbing box.
For what your doing, there's no way you need to put posts. Your just framing a box for stairs. We normally make a stairwell box opening a minimun of 38" x 9', double all the way around and put single and double hangers.
This is just my opinion and that's the way we frame here anyway. I can't tell you the loads and how much everything is carrying, I'm not smart enough that way. I'm just going by 19 years of framing and that's the way we've always done it.
There's a few guys here that can give you all the imformation on loads and all that. I'd be surprised if anyone told you to frame the box with a single joist.
Good Luck.
Joe Carola
Edited 6/20/2003 6:31:07 AM ET by Framer
I'm pretty satisfied with the idea of double joists. I just need to pick up another 11-7/8'ths to finish it out. My original plan was to make the square into a hexagon from the existing layout so that I provided maximum support... that is until I figured out I missed the dimension by 3 inches. After this new design I'll just have a couple of shorties to place .
The nice part of this new solution is it allows me to avoid cutting a 15 inch arc in the main floor installed porcelain floor tile that are on the other side (left in the drawings) of my now soon-to-be clipped sisters. I was envisioning a house full of smoke and dust from running a dry angle grinder with a masonry blade.
Thanks again.Jack of all trades and master of none - you got a problem with that?
Your Welcome.
When you double up the I-joist, you might want to get the flush mount double hanger and fill in the web. It's alot easier then using a top mount hanger in your situation. Unless the top of the perpendicular beam is exposed.
Good Luck.
Joe Carola
I just got up north to measure it out yesterday. 12 foot length for the original sisters and the headers to cut. Thought I had enough leftovers from the original framing. Unfortunately only one 14 footer left. I hate transporting those I joists cause they are so whippy on the rooftops. Guess I have to do it again.
Yes the face or flush type hanger will be necessary because the flooring is glued and nailed in place pretty securely. I looked at the price of sub-flooring adhesive and determined early on that more was better. No way to squeak a top mount hanger in there.
As with all of these cottage projects I'll be completing this project over the next 2 weeks. Whenever I get up there I'm drawn to too many projects. It is great for me, but a bit disconcerting to family & friends who come to help. I've got 6 months of loose ends to tie up.Jack of all trades and master of none - you got a problem with that?
Good Luck, I'm sure it will all work out for you.
Joe Carola
> They even make us double around the framing for attic stairs.
Yup, out here my engineer had me double around the attic access even without stairs.
-- J.S.
Yup, out here my engineer had me double around the attic access even without stairs
Same here John. They even make us double around the returns for HVAC.
The problem in NJ is that alot of these things aren't code. If you take out the code book some of these issues aren't in it. But what happens is that building inspectors make there own rules. You can take out the code book and challenge them and tell them to show you where is says to do xxx.
But now you have pissed them off and they will bust your ba!!s for everything else.
I never doubled around attic stair openings befor until about 8 years ago. Never put joist hangers on ceiling beams or skylight doubles befor until about the same time.
Window sills, never doubled them until about 10 years ago. If you check the code book.
I talked to the building inspector one day and he showed me in the code book that it dosen't require fire blocking up until 10' walls. For years every house I framed and seen every other framer frame puts fire blocks on anything over 8'.
There supposed to be coming out with a new code book and there's a big section for framers and I want it the day it comes out because I don't want to be doing any unecessary framing I don't have to or I don't want to leave out anything that is necessary. All I want to do is what's right.
I'll put doubles where they need to be, hangers where they want, whatever they want I'll do. But everyone in the state should follow the same book. They shouldn't allow an inspector make you do things that aren't in the book.
Joe Carola
Edited 6/21/2003 12:17:08 PM ET by Framer
Edited 6/21/2003 12:18:22 PM ET by Framer