Structural Repairs: How to un-butcher a house

Moving or removing walls, enlarging window openings, altering doorways-- these are major renovations that, while not especially difficult, require a clear understanding of the structure of a building. We unfortunately moved into a house where the previous owner had made numerous changes that compromised the structure. Notwithstanding the inherent danger of our investment collapsing (literally), we were faced wtih the financial hardship of undoing his work, fixing the resulting damages and compensating for the changes made to the structure.

The back dormer: water damage and improper window structure

One of the many attractive features of our current house was the built-in book case at the stair landing half way to the second floor. We thought this was the perfect location for our many photo albums. There was some evidence of a leak around the old window, which we had replaced. There was also some damage on the drywall ceiling where water had come in due to an improperly installed eaves trough. That problem, too, had been fixed shortly after we moved in.

The laminate top of the book case had been damaged as a result of the eaves trough leak, so I decided that I would remove the book case and build a new one (or not replace it at all). That was when I discovered that damage was far more extensive than I had ever suspected.

Originally, a built-in bookcase was situated on the landing between the main main level and second floor of our house which was part of a dormer structure. While it was not in the best shape, with a little cosmetic work we thought it would be the perfect place to keep our family photo albums. However, as the demolition of the second floor progressed due to the insulation issue, I decided to rip out the bookcase and build another one later. As I proceeded with the removal, I discovered the drywall behind was severely damaged due to a water issue.

The water infiltration could have come from two possible sources. The eavestrough had been nailed directly to the siding (there was no facia board) and water came in through the nail holes. I had witnessed this during a particularly heavy rainfall. When the roof and eavestroughs were replaced, I had a facia board installed to solve this issue. The other source of leaking could have been from the old window, but we had a replacement window installed which would have solved that issue. As i was demolishing the bookcase, siding was being installed on the exterior of the dormer so I was confident that any water infiltration was a thing of the past. However, I still had to deal with the damage that had been done.

The two horizontal 2x4s were the top plate of the main floor structure and
the bottom plate of the dormer structure.  They were so severely rotted,
that I was able to crumble them with one hand with very little effort;.
The studs were also significantly damaged.

The "Mickey Mouse" Fix

I attached a 2x4 across the studs and propped it up with a 3 or four other 2x4s supported by the floor of the landing (not shown). I then surgically removed all the damaged portions of the top plate and the studs. The new top plate in this area is somewhat lower than the original so that it could be securely fastened to 4x4 posts on either side of the landing area using Simpson Strong Ties. The studs were sistered and toe screwed to the new top plate. The sheathing was reattached to the new structure from the inside using L-brackets (also by Simpson).

I was fortunate that all the damaged wood was easily accessible once the wall was opened up. The rest of the dormer is part of the bedroom and the top plate supports the floor joists. That repair would have been truly nightmarish.

Window structure was not adequate

I was concentrating so much on replacing the rotted wood that I missed another obvious problem. At some point in this house's past, the original windows in the dormer were replaced with larger windows, but the installer did not properly modify the structure. Instead, he had just cut a larger opening and slapped the window in place. You can see how the studs had been cut to accommodate the window, but without a proper header supported by jack studs, the window is actually supporting some of the weight of the roof.

The repair I had done may have been adequate for replacing the existing structure, but it did not address the lack of structure around the window. I decided it was time to call in a professional contractor who had the experience and confidence to properly fix the dormer.

The Proper Fix

The window was removed and set aside. The 2x4 studs that were completely in this area were removed. The other studs were cut off at floor level.

A 2x6 bottom plate was installed, supported both by the studs and the floor of the landing. Next, the 2x6 top plate was added to the existing top plate. Then the new studs were installed. The header over the window, comprising of 2 2x8 with OSB sandwiched in between as a spacer, came next, followed by the sill and remaining studs. What was once a mish-mash of sloppy or questionable workmanship (including my own) is now a strong and sturdy structure. As an added bonus, we took the opportunity to move the window over so that it is now centered in the landing area.

Proper structure for doors or windows in load-bearing walls:

Proper framing for around openings

The header transfers the weight of the structure above the opening to the jack studs which are reinforced by the king studs. The size of the header depends on the size of the span and the weight it supports. Here, 2x8s are used.