Flat roof addition - Joists connected to structure via legerboard??

Rhino17 · 08-31-2007, 08:10 PM

We have a flat roof addition attached to our 40 year old house with a peaked roof (the addition was built before we purchased it). The addition has 3 exterior walls sitting on a cinderblock foundation, and one wall that is shared with the existing structure.
The flat roof is 16' wide, composed of 2x10 @ 16"oc. The roof of the addition is 2 feet lower than top of the existing wall is shares with the house, so the roof joists could not be positioned on top of the existing wall. Instead, they have been attached to the existing structure via a ledgerboard screwed to the brick wall, with joist hangers supporting the roof joists.

We have noticed some cracks in the drywall, and a large crack in the foundation (which has been repaired) My assumption is that this roof design provides no vertical support for the roof on one side, and it appears that the entire addition is slowly pulling away from the house, and taking a portion of the house with it!

We called our home inspector, who came out, had a look, and insisted that the ledgerboard is fine for connecting the roof joists to the existing wall, as long as lag bolts are used to secure it. Has anybody seen a legerboard used in this way before? Is it a suitable building practice?

Any thoughts would be greatly appriciated.

Rhino

Big Bob · 08-31-2007, 09:00 PM

"Has anybody seen a ledger board used in this way before?"

Yes, many times. Is your ledger board attached to brick veneer or structural brick? Sounds like brick veneer. If thats the case, get your money back from the yoyo home inspector.

Please post some pictures that will tell more of the story. How is the floor built? concrete slab or wood frame? Where is the foundation crack? How are your addition walls tied into the brick veneer? Any stress cracks there?

Close-ups an 10 to 15 ft away will help.
Was a permit pulled for the addition? Was it a DIY project?

Rhino17 · 09-01-2007, 07:56 AM

The addition was built in the early 70s without a permit. We were told by our real estate agent that most of the additions in the neibourhood were built without a permit. The home inspector said at the time of purchase that, although he couldn't see any structural details, the addition has been there fore 25+ years, so it must have been built well.

The floor is a 2x8 wood joist floor, with a concrete pier that runs up the middle of the room to support the weight of the floor.

I am in the process of removing the drywall on the wall and ceiling to get a better look. Will post pictures when I get it all opened up.

Rhino