Remove cinder blocks from foundation

Discussion in 'Remodel Forum & Blog' started by Master Brian, Jan 16, 2009.

  1. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    I have a 1915 Craftsman style house, that sits on a cinder block foundation.

    I am wondering what is the proper method for removing a section of blocks that is about 2' x 2'. This would take place directly under the sill plate, at the top of the block wall. I am needing/wanting to create an interior access to a box out is the goal.

    I would think I would need to build a wood header under the sill plate, but looking at the windows in the basement, they don't appear to have headers. Can I just remove the blocks, put a 2 x ? frame around the opening and build a door?
  2. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    Here is how they framed the basement windows. I wonder if I can cut out and do something like this.

    Any tips for cutting the blocks is appreciated as well.

    Attached Files:

  3. Basement_Lurker

    Basement_Lurker One who lurks

    Messages:
    668
    Location:
    Victoria, BC
    Are you sure than entire wall is made of blocks? The lower half looks as though it might be a concrete footing.

    If you want to continue the opening to the floor, your best bet to make a clean cut is to rent a hand held gas powered concrete saw and then use a grinder to smooth out any miscuts if necessary. You can then frame around the opening and support as needed.
  4. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    The entire wall is made of block. I don't know what they would have used as a footing in 1915, but I didn't think they used concrete. Could be wrong, but that is another discussion as I'm not getting into the lower half.

    Just for the record, I'm not taking this window out, I'm wanting to create an opening similar to it on another wall and that wall is cinderblock as well. I'm trying to gain access, from the inside, to a box out under my kitchen. Currently they have 3 loose cinderblocks on the outside wall and I'm having trouble keeping the box out heated underneath. If I can close up the outside and gain entry from inside, I can better insulate it, keep bugs & mice out, and have a better entry. The window is just to show how they did it and ask if I duplicate that on a smaller scale am I ok!?
  5. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Messages:
    885
    Location:
    South of Boston, MA
    That looks just like my basement windows
    I have a double top plate over the windows
    I have floor joists that sit on top of the 2x sill plate

    My basement door doesn't have any sill plate
    The only "header" is the single rim joist

    Are you looking to add just a small access door?
    Or a full height door?
    I'll have a basement door that will be added to the new garage
    The header will consist of the 2x rim joists on that side
    - Floor joists run parallel to the opening

    So this may depend upon which way your floor joists run
  6. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    I went home at lunch and snapped this pic. The area highlighted in yellow is the area I want to put the access door into. I can shift it left, right, etc. Nothing is set in stone yet. I'm hoping I only have to remove 2 courses of block. I just need enough room that a 200lb man can somewhat easily get into. Now and in the future, so maybe a 16" tall x 32" wide hole.

    BTW...the gas line in the upper left and the ABS drain pipe in the upper right will be moved. The electrical will be stappled up and out of the way.

    p.s. ....how about those jeans and spray foam someone used to insulate the gap around the gas line!

    Attached Files:

  7. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    The window shown is on the wall perpendicular to the proposed small door, so the joists run parallel to the window on that wall. Obviously in my picture where I want to put the opening, the joists run perpendicular. There is also a window on that wall and across the basement on the opposite wall, both are framed just like the window in the pic. right or wrong!

    Would I be better installing a 2x4 header for my door with some jack studs holding it up? Or am I ok, just installing a 2x4 frame under the sill plate as in the window pic?
  8. leejosepho

    leejosepho DIY scratch-pad engineer

    You would probably be okay just duplicating what you already have elsewhere, but there is no sure guarantee about that. I would probably make the opening only about 24" wide and center it between the joists on either side of the one losing some of its support ... then use a jack to put a little pressure on it (up) while adding a joist hanger and a double 2x4 header on crips.
  9. frenchie

    frenchie Jack of all trades

    NO! NO! NO!

    ...sorry for yelling, but this is pretty important.

    You can NOT just reproduce the same opening, in a wall perpendicular to your joists, as you could in a wall running parallel.

    A linear foot of the wall running parallel to your joists, is carrying a small fraction - a tiny, miniscule fraction - of the load that a linear foot of the perpendicular wall is carrying. They are not the same thing, at all.

    Especially with that joist terminating directly above where you want to put the opening? NO!

    Just throwing a 2x4 header in there, isn't enough, either - headers have to be sized for their loads, and just off the top of my head, a 2x4 isn't gonna cut it, here. I'm not going to make a guess over the internet, but I know it'll have to be beefier than that.

    This isn't a project you can just leap into, Brian - sorry. You need to consult an engineer before you start messing with the load-bearing parts of a house.
  10. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Messages:
    885
    Location:
    South of Boston, MA
    I have three windows that have rafters sitting on top of the 2x sill plate over the window (joists perpendicular). On of these only has floor load due to an LVL beam being installed. In the old days they installed windows like this. I would never install one that way today.

    Can you lower the doorway & put in a proper header & jacking studs?
  11. leejosepho

    leejosepho DIY scratch-pad engineer

    Read his posts again, Frenchie. He already has one just like that.
  12. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Messages:
    885
    Location:
    South of Boston, MA
    The fact that something was installed under old code (or lack of code) does not give you the ability to make the same installation today. Codes change for a reason. My old window just like that (perpendicular) no longer would open due to the weight that caused the double sill plate to sag over the years
  13. leejosepho

    leejosepho DIY scratch-pad engineer

    Ability is not determined by any code, but that is another matter.

    I do clearly understand the structural issue here, and that is why I had said whatever I did about "no guarantee" ... and if you look more closely at what I had actually written, I am quite sure he would be structurally okay. But of course, he is certainly completely free to hire a structural engineer and to update the entire framing of his house, if he wishes.

    Maybe I sometimes hear things funny, but Frenchie's self-admitted "shouting" sounded to me like some kind of melodramatic suggestion that duplicating an opening such as already exists would all but assure an imminent collapse of the entire structure ... and I cannot possibly believe anyone here would actually believe that. At the very least, you and I know far better!
  14. frenchie

    frenchie Jack of all trades

    I understood his post to mean, he had one like it in a wall parallel to the joists, wants to put one in the wall that's perpendicular.

    And no, I don't think his house would fall down. I think the floor above would get crooked, and I think the window would break, and I think it would take a while to happen. It would also create weird, unpredictable stresses in other part of the structure. As one joist sags, the next joist over becomes a pivot point, the next one out from that starts to lift, and depending on where those are in the house it can have all kinds of other effects... and so on.

    I realize I may have come off a bit too alarmist, but... I've twice watched a ceiling drop 3-4 inches, in a single, instantaneous "whomp!". It's pretty impressive...
  15. leejosepho

    leejosepho DIY scratch-pad engineer

    Looking back, I might be the one who made a reading error there ... and I certainly agree about the need for any changes to be done properly.
  16. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    frenchi, first I am not leaping into this, which is why I am here asking. I actually called a structural engineer on possibly changing a stairway and he said, just ask a competenant contractor. Maybe he just didn't want to mess with a small project.....

    I am also going to through this out there....

    I already have a window on the same wall. I'm not actually sure if the window opens, I'm not sure I've messed with it, some of them are screwed shut. This window is actually under a bay window box out, which might be why they were able to install it. Maybe the bay window changed the load!!?

    Yes, I can lower the height of the opening, it's not a big deal, just need room to get into the "hole". I can also shift left/right/up/down. One other thing that may or may not be important, this is on the gable end of the wall and like I said this "door" would go into a box out. Because it goes into a box out, there is actually no wall directly above where I want to put the opening. The wall is about 4' south. I've attached a pic to hopefully explain this. Again the yellow box is approx where I want the door.

    I know a gable end doesn't carry as much weight as the side walls. Then add to that, the joist is really only carrying the weight of the floor, no walls. What I don't know is what harm it would do adding the "door" to the wall considering there is already a questionablly framed window on the same wall. The part that also confuses me a bit is the direction of the floor joists. Like I said they run North to South, which are the gable ends of the house. The East and West walls are where all the weight should be, yet, these walls aren't sitting on the joists, just the sill plate! This must be balloon framed?

    What if anything does all of this change? I could easily add a 2x8 header, which thinking back to my framing days, should easily be enough, but if I do, I have to take one more row of blocks out. I would think the fewer rows disturbed the better.

    Oh yeah, if this makes ANY difference, I will be building a 2x4 wall 16" on center about 2" inside the cinder block wall, so that I may finish out the basement. This would also add some stability to the joists. It won't be a floaiting wall, as that isn't done around here.

    Attached Files:

  17. frenchie

    frenchie Jack of all trades

    Well, yeah - there's standar rules-of thumb for these things. A competent contractor who can see your house in person, could probably answer this question, too. But if you want to DIY it...

    That's pretty weird - I've never seen joists terminating on the gable end, before. So the ground floor is framed perpendicular to the roof...? Any idea which way the 2nd floor joists go?

    And yes, the absence of a wall changes everything. In your drawing, most of the load from upper floor & roof is bearing on the two posts (or would be, if this wasn't a gable end). So the only load above your proposed opening, is that one joist's share of that one floor...

    I can't see your house from here, to know if there's anything else weird about it. But glancing at my header table really quick, a 2x8 would be overkill if the situation is exactly as you described (no load bearing wall above, the opening about 30" by the looks of it?). Doubled 2x4 would probably do.


    Unless you're digging a proper footing under that wall... no, it doesn't change anything.
  18. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    frenchie, my neighbor who is a licensed brick mason will likely cut the opening or guide me in doing so. I also have a good friend whom is a licensed contractor and very competant, if I get in a jamb, he would also likely come to my rescue.... I just hate bugging him about this stuff all the time.

    I've never seen the joists terminate that way either. It is strange, but the house is very solid! The 2nd floor joists will really get you....1st, there are 2x4 joists, which run parallel to the gables. 2nd directly on top of those are 2x6 joists which run perpendicular to the gables. My guess is that at some time in the past the house wasn't intended to be a finished 2nd floor, so they just ran the 2x4's, then they decided to finish it off. The confusing part is the 2nd floor, if finished after the fact, was finished not long after the fact, as it is primarily lath and plaster, with the old style doors and wiring....

    As for the 2x4 basement wall, depending upon what they did for a footing, I figured I might, purely accidental of course, catch part of the footing from the cinderblock wall.
  19. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Messages:
    885
    Location:
    South of Boston, MA
    The header above does change everything
    What I would do:

    Put the opening so that only one joist will be effected - as you have drawn. Put a joist hanger on that floor joist to secure it to the rim joist
    Is it a single rim joist or double rim joist?
    If a double rim joist then it will serve as your header
    If a single do you thing you can secure another rim joist on the opposite side once you go thru the wall?
    If so I would do that & make sure it extends past the next floor joist on either side

    My floor joist in the basement change direction every where for several rooms. Older houses... different building methods
  20. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas

    Not sure of single or double. I will see if I can tell, but that might not be easy. I am however pretty sure I can double it up on the other side, that will of course depend upon if I can get another 2x8 inside the box out.

    Question on the joist hanger, I'm not sure I can get in there to nail it, are there any screws that would work?
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