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  1. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    I do think the gable dormer is in reality providing some thrust resistance (see one of the other replies where this was discussed as well) but I am very reluctant to count on it. What I'm getting from most replies is I am right to be reluctant.
  2. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Good advice and that's kind of where I am going with this. I think the existing roof is somewhat functioning as a "teepee" with the two valley rafters in the front and one (likely more) of the common rafters on the back acting compositely as the third leg. So although technically flexural...
  3. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Not easily....
  4. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    It's a constructability issue. If I had room, I would have just gone with the quad 18" LVL on PSL columns awhile ago. Rent a crane for half a day. This is on a dense city block. A crane would require a street closure, which the City won't give us. Needs to be carried up 3 flights of stairs...
  5. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Sorry, that's not a stiffleg on the left in the original. Proposed partition wall to finish off the new room. Photo of existing valley rafter where it meets existing brick wall attached.
  6. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    I'll consider screws. It's a row house on a city block. Common walls. Can't cut through the gable.
  7. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Yeah...the contractor on this job would put this right through the floor....trust me :)
  8. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Existing is plank, but he'll re-sheath/ shingle as part of this project.
  9. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    This was the solution I was leaning towards. The contractor is, how shall I say, unsophisticated? Trying to make it as easy for him as possible. I would have preferred to have a new beam built on the ground; set it and forget it. He'll have to get some temporary supports in there (that he...
  10. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    The existing hip rafters do not have vertical supports. We are in Upstate NY, so we get snow once in awhile :) This is the second attic I've been in in this area with valley rafters framed this way, and I am honestly not sure why this hasn't collapsed. Century old buildings, both of them. I...
  11. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    I can get a quad 18" to work. This needs to be lifted into place by hand; can't get a crane in. That's about 700 pounds of engineered lumber.
  12. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    Sorry. Sketch is proposed. Right side shows the proposed shed dormer with raised section. Left side shows the existing roof with the existing gable dormer coming in at midspan. Yes, I hate brick. This detail needs attention for the uplift. Still working on seeing if the roof is feasible...
  13. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    It is just a box. 33'-2" in the direction perpendicular to the ridge and 21 ft wide int he direction in and out of the page of the original sketch.
  14. Matt PE

    Shed Dormer on House w/ Exist Gable Dormer

    I have a client that wants to put a shed dormer on the rear of an existing 2.5 story brick house to convert the attic into living space. Dormer is to run the entire length of the building (21 feet). Plan is to cut out the rear of the roof, anchor a sill to the existing brick, install a 2x6...
  15. Matt PE

    Cracking in Wood Joists

    I probed a few places with a pocket knife. Boards were sound and offered resistance. No penetration with "normal effort".
  16. Matt PE

    Cracking in Wood Joists

    Thanks Ron, that's about the right era for construction of this house. I don't recall seeing any grade stamps. I'll have to look back through my photos to see if I picked one up in the background. Good to know. I think the answer is sistering. Still trying to figure out exactly what the...
  17. Matt PE

    Cracking in Wood Joists

    Correct, shear check at d/2 away from bearing. The cracks are in the ends of the joists, over the bearing, where you might expect high shear, propagating maybe 12"-18" inward. However, calculation shows shear in this region should only be about 30% allowable. Looking for some validation could...
  18. Matt PE

    Cracking in Wood Joists

    GTE, I agree with everything you are saying. I would not expect a shear failure unless there was a point load coming in somewhere. It was just odd to me that I had those cracks on the end of every joist on the longer span (not all of them had that distinct pith....maybe a bad picture to share)...
  19. Matt PE

    Cracking in Wood Joists

    Should have added that there is another area of the crawlspace where the joists are on a shorter span and none of them exhibit the end cracking. That area is isolated however and definitely damper, so can't rule out drying shrinkage where I am seeing the cracked joists. Both sets of joists are...
  20. Matt PE

    Cracking in Wood Joists

    Thanks GTE, Maybe it is checking. I appreciate the second set of eyes. I didn't want to immediately go there and write it off. The joists calc out a little light for that span in bending and we have visible deflection/ serviceability issues at midspan as expected, so I still think I am going...

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