A-frame roof to flat roof transiton failure at truss heel
A-frame roof to flat roof transiton failure at truss heel
(OP)
This is my "in-laws" house and I need some advice on how to proceed. It is a single story residence located in Miami, FL. Concrete block exterior walls with wood framed roof. Monolithic concrete slab foundation. Built in 1955.
There is a sag on the roof. The sagged area is about 4-5' wide. Here is an overall roof layout. Most of the house is on an A-framed roof, but on the SE corner there is a flat roof section. The sagged area is just a few feet west of where the hip roof and flat roof meet.

Here are two pictures of the roof above. The A-frame portion is shingle roof and the flat portion is flat deck concrete. You can see where the sagged area is. I can't tell for sure, and it seems barely appreciable, but the roof ridge line may be off a little as well...but the amount is so little, it could easily be bad shingle work as well.


Next I went below to look at the location inside where it corresponds to the sagged area above, by transferring the measurements. You can tell, the sag is visible. The ceiling is sagging as well.

So this is not some roof deck getting wet and rot and bow, something is off.
Next I crawled inside the attic, to see what's up there. I can't get real close to the sagged area because there is no head room. But with a flashlight I can tell there doesn't seem to be any roof leak or moisture penetration. The trusses look OK.



So the next step was I moved all the furniture out of the way and took down about a 30" wide strip of ceiling sheetrock where the sag is so I can see how the transitions look between the heels of the trusses and the flat roof framing. By removing the sheet rock in that room I exposed five trusses and I can see four of them have "dipped" at the heel where the transition is. The heel of the trusses and the metal brackets mounted on the flat roof 2X6s came apart a little. The biggest dip is about 1.5" or so.



A close up of two of the heels.
This one looks OK.

This one doesn't look too good.

Now the entire flat roof section is about 21' wide, the sag is only happening over a 5-6' portion of it. It turns out the room south of the sagged roof room, has a tie beam across that spot.

So it seems I need to jack up the truss heels back to level, then install a beam across it?
I wonder how the trusses will behave as I jack up one end of it's heel for an inch. Would the 1"X6" roof deck pop and warp as a result? Can I use a bottle jack across at the heels? Thanks for any comments and replies.
There is a sag on the roof. The sagged area is about 4-5' wide. Here is an overall roof layout. Most of the house is on an A-framed roof, but on the SE corner there is a flat roof section. The sagged area is just a few feet west of where the hip roof and flat roof meet.

Here are two pictures of the roof above. The A-frame portion is shingle roof and the flat portion is flat deck concrete. You can see where the sagged area is. I can't tell for sure, and it seems barely appreciable, but the roof ridge line may be off a little as well...but the amount is so little, it could easily be bad shingle work as well.


Next I went below to look at the location inside where it corresponds to the sagged area above, by transferring the measurements. You can tell, the sag is visible. The ceiling is sagging as well.

So this is not some roof deck getting wet and rot and bow, something is off.
Next I crawled inside the attic, to see what's up there. I can't get real close to the sagged area because there is no head room. But with a flashlight I can tell there doesn't seem to be any roof leak or moisture penetration. The trusses look OK.



So the next step was I moved all the furniture out of the way and took down about a 30" wide strip of ceiling sheetrock where the sag is so I can see how the transitions look between the heels of the trusses and the flat roof framing. By removing the sheet rock in that room I exposed five trusses and I can see four of them have "dipped" at the heel where the transition is. The heel of the trusses and the metal brackets mounted on the flat roof 2X6s came apart a little. The biggest dip is about 1.5" or so.



A close up of two of the heels.
This one looks OK.

This one doesn't look too good.

Now the entire flat roof section is about 21' wide, the sag is only happening over a 5-6' portion of it. It turns out the room south of the sagged roof room, has a tie beam across that spot.

So it seems I need to jack up the truss heels back to level, then install a beam across it?
I wonder how the trusses will behave as I jack up one end of it's heel for an inch. Would the 1"X6" roof deck pop and warp as a result? Can I use a bottle jack across at the heels? Thanks for any comments and replies.





RE: A-frame roof to flat roof transiton failure at truss heel
I would expect it to be done as follows. Use a spreader beam, push them as a unit. Go slow. Expect that you may have additional drywall repair from the jacking process (joints cracking etc). Also, make sure whatever your jack is on (main floor over basement, or slab etc) is adequate to support the jacking load or you could have other unintended issues.
I would bet that those hangers are undersized for the valley build-up loading that happens there. I don't have a dimension on the living room 2x6 span, but a double(triple?) 2x6 seems a touch light (ok...way light) to be acting as a beam for those gable roof trusses. It's also likely that the 2x6 "beam" deflected enough to cause water ponding. Edit: upon another look at the pictures, are they 2x8? Ponding may still be an issue with the deflection of a built-up 2x8, but 2x8 would be more reasonable than 2x6.
Edit 2: I see palm trees, so ignore my comment about valley loading, I doubt snow happens often.