No interior access to basement, can I go through the floor? 2

[emissaryx]

I am looking at an old house in Maryland with a full basement, walkout stairs (exterior), but no interior access to the basement. I would like to add access to the basement by cutting a circular hole in the floor and putting in a spiral staircase. I think I can go as small as 44" diameter. However, in order to do this, I would have to cut some floor joists.

Is it possible?
Will it remain up to code (if done right)?
Will I have to add support from the floor of the basement to the joists for the floor?
Would I just put in headers to distribute the load to the surrounding joists?
How wide can I go - how many joists can I cut ?

Thanks in advance!
Dustin

 

[LeoSC]

You need to retain an engineer to help you with this. I'm sure an engineer will be able to come up with a solution, but not without seeing the house.

 

[emissaryx]

Agreed, I do not recall the specifics (joist size, spacing, height, lengths, etc) needed to begin to solve the issue. I am hoping someone can tell me what they have done from past experience. I am sure many of you are like me, once I start thinking for a solution, I do not stop until I come up with one. I would like to hear what possible options I may have.

 

[RDK]

If it’s an old house it is most likely not to code in the first place.

To answer your specific question, generally yes you could cut through some joists to put in a stairway. You would have to put a header across the opening and perhaps add some additional joists or columns around the opening.

For specific advice get a local structural engineer who is familiar with wood frame construction to look at the house and provide his or her recommendations. Its not difficult, you just have to do it right and provide the correct temporary supports while you are doing it.

Circular or straight stairway does not matter too much. What is important is how many joists you have to cut.

A typical floor joist spacing is 16” o/c. A stairway could be as narrow as 22 ½” which would require cutting one joist. (That is typical for folding attic access ladders, you would want more width for a daily use ladder.) You would then have to double up the two outside joists and place a header across the opening to support the end of the cut joist (both ends). If you wanted a wider stairway then you would cut two joists and may have to use a double header depending on the length of the joist remaining. But then your local engineer can give better advice after seeing the building.





Rick Kitson MBA P.Eng

Construction Project Management
From conception to completion

http://www.kitsonengineering.com

 

[msachine]

dear friend u have not menstioned floor to floor ht.i,e basement to G.F .why u r not trying for M.s spiral staircase

 

[emissaryx]

From the basement floor to the top of the ground floor is about 8'. What do you mean by a "M.s" spiral staircase?