Unfinished rooms on second story

Discussion in 'Walls and Ceilings' started by MickChuckB, Oct 4, 2011.

  1. Oct 4, 2011 #1

    MickChuckB

    MickChuckB

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    I bought 2 story home (built circa 1972) in March in need of some work. Structurally sound, move-in ready, but in need of plenty of touch work and plenty to be updated/renovated. There are six rooms upstairs, 2 regular finished bedrooms, 2 full size bathrooms (one fully renovated by previous owner) and two completely unfinished rooms with plywood floor, no insulation and exposed underside of roof. Technically, I guess they would be considered attic space but it's odd to me that there are unfinished spaces on the same floor as the master bedroom. I have approached finishing these rooms as I would any attic space (install a knee wall, place ridge vents between insulation, etc). Being new to DIY, I overlooked one crucial part of the process that now has me stumped. In these unfinished spaces, there is no ceiling. The space is joined to the attic above it. I obviously need separation between the attic and the second story spaces to have the upstairs properly insulated but I have no idea how to extend the ceiling out. It's only about an 18" gap between the wall and the underside of the roof but I don't know if the smart move is to sister up the ceiling joists or consider replacing them with longer ones. Once it's extended, can it simply be secured onto the underside of the rafters or does that place too much stress on the roof. I've attached an actual picture as well as a crude drawing with labels. I feel like I may be over-complicating this entire process.

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  2. Oct 4, 2011 #2

    nealtw

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    The wall you want to remove is a bearing wall. You may be able to replace it with a beam but the beam would have to be supported all the way to the foundation. They have run the floor joists all the way to the outside wall so I doubt if there is a wall below this, so the weight is being transfered to the walls thru the floor joists. To install a beam that is not full length, the weight would want to come down on a two or three ply floor joist or more, maybe another beam. This should be designed by an engineer.
    Yes it is a bearing wall because it replaces all the angle braces found in unfinished attics.
     
  3. Oct 4, 2011 #3

    MickChuckB

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    Thanks for the advice, Neal. There is actually another wall directly beneath this but even the suggestion that this is load-bearing makes me cringe. It really kills me that this house was designed this way as its about 200sq ft of unused space even after accounting for lost space behind where I installed the knee wall. This is becoming a much larger project than once assumed, but I think it's necessary all the same.
     
  4. Oct 4, 2011 #4

    nealtw

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    I would have an engineer look it over so you would know what can and can't be done.
     
  5. Oct 5, 2011 #5

    BridgeMan

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    OK, I'm an engineer, and have looked at the pictures and comments. And I have to admit, I'm confused (certainly wouldn't be the first time!).

    Where is the load-bearing wall nealtw is talking about with respect to the new knee-wall that you built? I don't see it in the picture, although the "wall to be removed" in the sketch appears to be the knee-wall. Roofs designed to be supported by rafters often don't require any additional bracing (of the rafters) if the section modulus/span/spacing numbers are correct for the applied loads. Collar ties, when used, are only to prevent the rafter toes from spreading outward, and to prevent rafter uplift during a major wind event.

    You may not have nearly as large a problem as you think. Particularly if there are other rooms in the upper level with functional wall/ceiling framing similar to what you'd like to do in the unfinished rooms.
     
  6. Oct 5, 2011 #6

    nealtw

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    Bridgeman: How long do you think those rafters are and what do you think they are 2x8, 2x10?
     
  7. Oct 5, 2011 #7

    inspectorD

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    Since you most likely are going to need a building permit to finish off the room correctly. just ask your Building official to come out and take a look. You may need attic ventilation, updated electrical if this is to be a bedroom. You will need emergency egress and make sure the structure is Ok as far as collar ties go.
    This is an easy DIY project, you just need someone there making these decisions for your area.
    Be safe.
     
  8. Oct 5, 2011 #8

    MickChuckB

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    Hey Bridgeman, I realized how confusing the post was after Neal replied but he seemed to fill in the blanks quite nicely. When I made that little stick drawing in MS Paint, I didn't show the knee wall. The drawing is shown as viewed from the same angle as the picture so that may alleviate some confusion. I'm also going include a blueprint I mocked up (also very crude) so you can understand what I'm trying to do. The print shows the upstairs as it is currently configured.

    [​IMG]

    [​IMG]

    The space I've been working on is the one in the bottom left corner of the print labeled "Attic Space 2." As you can see it is a large portion of the upstairs and backs right into a bank of closets. When I made this drawing, I only included usable space so the bottom left wall that runs horizontal on the print (left to right) would represent the aforementioned knee wall.

    When I made the post I only made mention of insulating this room's envelope as that would be the first major hurdle to cross. Neal obviously noticed the label on the drawing indicating a wall is to be removed so I guess I should elaborate. The closets that back up to this space are as equally wasted space as the attic space behind it. They make up the 3 of the 11 closets in common space in the house, not to mention the closets in each of the rooms. I simply don't need that amount of storage space. The idea is to properly insulate the outer walls (I'm calling the underside of the roof a wall for simplification) and then knock out the bank of highly-redundant closets to give me a loft-type area at the top of the stairs outside the two bedrooms. Also, in case I have not made it clear there is still above-ceiling attic space above this story. All the rooms that are not labeled "attic space" are fully completed, insulated rooms. I'll take a better picture of the space on my lunch break so you can get a better idea of what I'm trying to do. When I stumbled across this forum, I posted the only pictures stored in my phone at the time. I honestly did not expect that I would get this level of assistance on here so I stopped at the two original pics. You guys really are a big help.
     
  9. Oct 5, 2011 #9

    nealtw

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    Just to clarify my concerns. I suspect that the rafters are 20 plus ft long, evan if they are 2x10 which they should be to allow venting above, they would be way over spaned, not to mention the weight of the ceiling in the finnished room. The rafters may evan be joined over the wall in question.
    I don't think there is a builder anywhere the would want to put that wall there, the only thing that comes to mind is an engineer said build the wall here. Moving it without doing all the research and calculations would be foolish and dangerous.
     
  10. Oct 6, 2011 #10

    BridgeMan

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    Sorry, nealtw, but my X-ray vision is on the blink, making it impossible for me to see through the insulation and guesstimate the rafters' depth (or span, for that matter, as the tops are out of the pic frame).

    The old house we're currently in has a very similar upper floor with a slightly shallower rafter pitch (8-on-12; Mick's pic looks to be about 12-on-12), and a horizontal run of about 14'. Our kneewalls are just a tad more than 4' in from the sill plates. If I remember correctly, our rafters are 2 x 8s on 2' centers, and have an overall length of about 17'. They are all rough-sawn old growth Doug fir (no knots anywhere), with an allowable repetitive-member bending stress of at least 2000 psi. We had the old skip-sheathing overlaid with new 1/2" plywood when new 40-yr. (heavy) shingles were installed a few years ago, and the roof is still plenty stout. Can't get it to deflect an iota, even when I bounce my 260 lb. of solid muscle (OK, blubber) on it a few times. Meaning, in a round about way, there's a good chance that Mick's rafters, if nominal 2 x 8s but being less stout and lower strength, could well be maxed out with his longer span.

    Mick, you might want to look into your local Building Code requirements about headroom restrictions for liveable space. I know our local Code strictly adheres to the IRC-required 7' minimum for heated areas, with no exceptions for sloped ceilings that the IRC allows. Which could put a serious damper on your wanting to remove the existing wall in your unfinished rooms to open them up.
     
  11. Oct 6, 2011 #11

    nealtw

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    Bridgeman;
    As an engineer yourself you should know better than giving the quick easy answer especially when the ex-ray eyes aren't working. We don't know that the rafter aren't
    2x4s joined in the middle.
    Keep in mind, the home handyman type often know just enough to be dangerous and will often just take the easy answer and go for it. Adding to the problem is the fact that the answer came from an engineer.
    I think it's great for people like Mick to come to a place like this for more info and I beleive it is up to us to give him as much info as posible so he can make his own decisions.
     
  12. Oct 6, 2011 #12

    MickChuckB

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    Ha, don't worry Neal. I'm merely looking to be aimed in the right direction. I wasn't planning on taking information from a message board and pretending I'm some kind of expert. I intend to bring in a pro at some point, but as someone who works somewhat in the construction industry I understand that you can quickly be taken advantage of if you don't know what you're doing or don't have a very specific plan in mind. Here's the rafters before the insulation was put up.
    [​IMG]
    They're spaced 16" and I'm pretty sure they're 2x8s, but that's a complete guess. I'm sitting in my office at the moment so I don't have a quick answer. No clue on the pitch, but 14' - 17' in length seems like a pretty spot-on guess. I hate to hear about the lack of exception for sloped ceilings. I'll have to see if that is the case in Atlanta. I guess it's time to crack the books on local building code. It should be a welcome break from this NFPA 72 that I have been cramming into my head these last few weeks.
     
  13. Oct 6, 2011 #13

    MickChuckB

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    I stopped by my house on lunch and measured the rafters. Much to my dismay, they are 2x6s. It seemed to be a foregone conclusion that they should not be supporting any additional weight so I'm not all that deterred. It seems evident that a beam will need to be installed (assuming any of this will be allowed per code). Luckily, I'm young and single so I've got all the time in the world to tinker and plan. This is the backside of the wall that I intend to move/remove. You can see that there's about a 1-2ft gap opening at the top that goes into the attic.

    [​IMG]
     
  14. Oct 6, 2011 #14

    nealtw

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    It does look like you have better than 16 ft between the outside wall and the peak. I am really surprized that the added room wall didn't extend to the roof and there are no angle braces. Your knee wall shortens that some BUT I would still be concerned about wind loading and the flex of these 2x6s, If the knee wall is close to the exterior and you get any amount of flexing in the remaining 13 ft, the nails going into the outside wall could be stressed.
    Extending the ceiling over to the roof will help but some one that really understands roof structure needs to look it over.
     
  15. Oct 7, 2011 #15

    BridgeMan

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    nealtw--

    Sorry, but I'm having trouble understanding your "quick and easy answer" remark. How you read that into my refusal to guess at a load-carrying member's size or span based on pictures is beyond me. Could it be possible you were confusing my comments with those of InspectorD? He mentioned in Post #7 that "this is an easy DIY project" (which is a statement I'd be reluctant to make, as there are too many variables and unknowns that could quickly complicate matters). And to further clarify, any suggestions or answers I make as an engineer are never intended to encourage anyone to do something that's beyond their limits and capabilities.

    But getting back on point--Mick, with your rafters only being 2 x 6s, they could well be at their maximum span limits when unsupported at an interior point. American Forest Products span tables for 2 x 6s @ 16" centers shows them only good for a 10'-0" span (assuming Fb of 1800 psi, allowable deflection of L/240, liveload of 50 psf and deadload of 10 psf).

    As an aside, I noticed in one of your pix that someone drilled through several adjacent rafters for the purpose of running Romex (electrical wire). Doing so near the center of a span (where its bending moment is greatest) is bad practice, especially when the holes are located in the lower half of the member. In effect, this has turned each 2 x 6 into something considerably weaker. Better to locate holes closer to the neutral axis (center) instead of the tension zone (bottom) of a member, and to make them as small as possible. And better yet to not put any holes in the middle third of any rafter or joist span.
     
    Last edited: Oct 7, 2011
  16. Oct 7, 2011 #16

    nealtw

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    Bridgeman: All I am saying is if you go back and look at all the pictures, do you see a problem with span length, bracing and do you see a bearing wall. I was that that guy with a hammer and saw with an attitude of "lets getter done" and I know the damage that can be done.
    Does the follwing statement help some one understand all the problems he may face?
    "You may not have nearly as large a problem as you think. Particularly if there are other rooms in the upper level with functional wall/ceiling framing similar to what you'd like to do in the unfinished rooms"
     

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