How crazy would it be to turn this 100% unused attic area into a rec/living room, bat

Discussion in 'General Home Improvement Discussion' started by proprojects, Aug 21, 2011.

  1. Aug 21, 2011 #1

    proprojects

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  2. Aug 22, 2011 #2

    nealtw

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    After you have the roof off is not a good time to be looking at this.
    As you have rafter and not trusses you have a better chance than most. Your first trip is to the city. They will tell you if it is allowed and how detailed a plan you need and if you need an engineer to be involved.
    Besides changing the roof lines you are adding floor joists and bearing points all the way to the foundation and maybe underpinning there. You will also be looking at stairs wiring and plumbing.
     
  3. Aug 22, 2011 #3

    proprojects

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    What are the chances that the current ceiling joist hidden by the insulation could also support the floor? Do they need to at least be a 2x6, 2x8 or 2x10 to support a flooring substrate? The house has a new roof on it now, I was looking to open up the gables on the ends and adding in bay type windows.
     
  4. Aug 22, 2011 #4

    BridgeMan

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    From what little I can see from the picture, I think the attic would be a good candidate for making into additional living space. It appears the roof rafters are 2 x 6s, on 24-inch centers, and are being given additional support by the diagonal kickers. The kickers would of course have to go, but the pony walls you build on each side will easily replace them (if properly constructed). The 2 triangular spaces behind the pony walls would make good locations for running your new wiring and possibly plumbing, and if you run the new floor sheathing all the way out to the rafter bottoms, the spaces could make good storage locations as well. To properly insulate the attic area, you'd probably need to increase the rafters' depth to allow space for some R31 batts before sheetrocking.

    Regarding the floor joists--the type of wood, grade, joist spacing, joist depth and wall configuration in the living level under the attic all need to be evaluated by someone qualified to do so (licensed engineer in your state) to determine if the existing members are adequate or if and how they can be strengthened to support the new living space loads. The bottoms of the kickers in the picture are probably located at interior walls, which would increase the likelihood of the floor joists being workable because of shorter effective span lengths.
     
  5. Aug 22, 2011 #5

    nealtw

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    The cross bracing that ties from the center of rafters back to the center of the house would have to be replaced with the pony walls and have to land on something that can support the weight, so you would need at least 2x10, 16" on center from a center wall to the outside wall and you probably do not have room on the outside between the wall and the roof sheeting for a full 2x10. You would be adding 100 pounds per sq. foot before furniture. Would your stairs run in the same direction as the rafters or not?
    It's great to look at all this stuff but the foundation and footings are the real question.
     
  6. Aug 23, 2011 #6

    BridgeMan

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    nealtw, it sounds like Canada has more conservative design load codes than here in the U.S. (heavier people up there, eh?). Although I am not a design engineer, I think the 100 psf design load you're suggesting is a bit too high. My copy of the IRC, Section R301, calls for bedroom floors to meet 30 psf live load. Adding another 10 psf for dead load, and even throwing in a roof snow load factor distributed through the pony walls would probably add only another 20 psf or so, for a total of 60 psf.

    Another thought--if the existing floor joists are only 2 x 8, the floor could be made workable by either sistering in (doubling up) additional 2 x 8s, glued and screwed, or even splitting the existing joist spacing in half by inserting new 2 x 8s between them.
     
  7. Aug 23, 2011 #7

    nealtw

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    Bridgeman: Like I said , we need an engineer here. When removing cross bracing adding load bearing pony walls near the center of the floor joists. I will over estimate the weight every time, and let the onsite engineer correct me.
     
  8. Aug 23, 2011 #8

    oldognewtrick

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    And we have a winner! I remember a house not to far from me that was a ranch style house. The homeowner thought that it would be a good idea to add a second story and double the living space. Permits?? Nope, didn't need them. Engineer??? nope didn't need to spend the extra $$$ for a engineer. Consult or hire a contractor??? nope, all they do is take/cost the money. Well guess what...yep dropped the hole structure inside itself, luckily no one was killed. Bulldozer, clean earth, new building...

    If you're planning on changing load points, cutting bracing/changing rafters get some advise from someone who understands building dynamics.
     
  9. Aug 23, 2011 #9

    BridgeMan

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    All right, I confess. I'm a semi-retired civil engineer, first licensed in 1971, at one time licensed to practice in 7 states (but currently only licensed in 3, as it's too darn expensive renewing them when I'm not bringing in the coin). To date, I've performed more than 3550 structural inspections of residential and public infrastructure facilities in 12 states. But contrary to the majority of engineers I know or have worked with, I still practice the more conservative working stress design method when asked to crunch numbers, and I'm not afraid to look at the practical side of things, nor do I hesitate to use logical common sense when addressing challenges and problems. Oh, and did I mention that I love getting my hands dirty, working with steel, concrete and timber construction?
     
  10. Aug 23, 2011 #10

    inspectorD

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    Looks like a job for an engineer ....actually on the job, from my couch anyway.;)

    Looking at the skip sheathing for the wood shake roof that used to be there, and the non- dimentional wood from a factory setting, I'm wonderin what the foundation is for the house of that age....and if there are any bug infestations from the non kiln dried lumber common to the older homes.:2cents:
     
  11. Aug 23, 2011 #11

    proprojects

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    Thank you for all the replies and suggestions.
    I need to check out what the boards are under that insulation. The stairs unfortunately would not run with the joist. The house was build in 1930 and the best part of the foundation is under the old coal room (it had a footer added in), outside of that the weaker area of the foundation has 3 supports added in for the floor. The foundation has had several "repair" jobs and at 1 point new base boards got put in under half the house. The point of getting an engineer is 100% understood and agreed with, I wanted to learn a little bit before paying people to come in and tell me "this isn't going to work out". Thanks again!

    Positively speaking, I have plenty of open breakers in the box and the heating/ac unit can easily take the extra work load! :beer:
     
  12. Aug 23, 2011 #12

    nealtw

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    Now that your roof is repaired check again that the soffit vents didn't get plugged up.
     
  13. Aug 23, 2011 #13
    I think it has some potential. I'd love to see what you do with it.
     
  14. Aug 23, 2011 #14

    proprojects

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    It has 2 gable vents only, 1 on each side of the house (level with each other). This gable vents would likely become some sort of window opening. Called and left a message with my towns zoning guy and called a local engineer this afternoon, I need to make some drawings of what I have and what I want to do then he will meet with me at the house.
     
  15. Aug 24, 2011 #15

    nealtw

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    If you go ahead with this you will want to do the math and make a plan for venting the roof. It's really important for attics with bonus rooms. You would need soffit vents to allow air in at the bottom if the rafters and install more than required vent on one side of the peak to let the hot air out. The rafters will need to be enlarged in the room area to allow 8 to 10 inches of insulation and still have 1 1/2 to 2 inches above that for air to move freely. Build pony walls with 2x6 for more insulation with scraps wood nailed across the back to hold insulation in place.
    After the engineering the venting is most important!!
     
  16. Oct 26, 2012 #16

    proprojects

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    I've read all kinds of stuff online about roof height minimums, I have 89" from the current floor to the rafters at the center. After adding rafters to allow spacing for the insulation and a subfloor I could easily have less than 7' in the center. Are there codes on a house built in 1930 for livable spaces vs closets and office space?

    JR
     
  17. Oct 26, 2012 #17

    nealtw

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    I think in most places your min. is around 80" the height of a door.
     
  18. Oct 26, 2012 #18

    BridgeMan

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    You need to touch base with your local AHJ (the people who will issue the building permit after reviewing your remodel plans) for an answer to that question. I believe the IRC requires at least 50% of a living space have a ceiling height greater than 7'. Some local jurisdictions are known for relaxing current code requirements on older buildings, while others don't allow any leeway.
     
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  19. Oct 27, 2012 #19

    AndyGump

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    Here is that code section, IRC 2009.

    Andy.
     
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