Q: What is the best way to attach a framing ledger to my brick veneer house? I’ve looked at the SimsonStrong Tie BVLZ connector but it is not approved yet in Ontario, Canada.
I’m building a one-story addition with a low-slope roof that will attach to a two-story brick-veneer exterior wall.
The floor joist ledger is attached directly to the foundation. I wish to attach a second ledger on the brick veneer to support the roof rafters. I want to keep the brick in place so that it becomes an interior wall of the addition. Thanks. — T. Slavin
A: Building codes have many gray areas that are open to interpretation, but the IRC (International Residential Code) is very clear on the issue of attaching structural ledgers to brick veneer: Don’t do it!
While the IRC does not specifically address attaching ledgers for floor joists and roof rafters to brick veneer, it provides clear guidance for deck ledgers – and the structural issues are very similar.
IRC Rules for Ledgers on Brick Veneer
The 2018 IRC, Section R507.9.1.1 states: “Deck ledgers shall not be supported on stone or masonry veneer.” The reasons for these rules are pretty obvious. Brick and other masonry veneers are designed to support their own weight only.
Brick veneer is not designed to support additional vertical or lateral loads even if the brick ties were properly installed and are still in good condition – not always the case. Often the ties have loosened or deteriorated over time, and in some cases were never installed in the first place.
The widely used Prescriptive Residential Wood Deck Construction Guide , based on the IRC, takes the same position. In the section on ledgers and lateral loads, it states in bold caps: DO NOT ATTACH TO BRICK VENEERS. To emphasize the point, an illustration of the prohibited detail is included (see below).
While the codes don’t explicitly prohibit using brick veneer to support a ledger for a floor or low-slope roof, I expect that every building inspector would draw that conclusion. The loads are very similar.
That said, a lot of residential decks are attached, one way or another, to masonry veneer. Of those that have survived, some use specialty hardware, some have custom engineered solutions, and some are hanging by a wing and a prayer. They are holding up, in part, because structural design has a large safety factor built in. But, without the safety factor, you are living dangerously. With a backyard deck a foot or two off the ground, the risks of failure are not so great. With an elevated deck or roof, the risks are significant.
Simpson BVLZ Connector To the Rescue
To address the problem of attachment to brick veneer, a few companies like Simpson Strong Tie have developed specialty connectors as a workaround. The Simson BVLZ connector is the best known for retrofit applications. The connector installs from the exterior with two 14-in. structural screws and a “compression strut” to bridge the gap to the house’s band joist. The two 14 in. screws are driven upward at a 40° angle.
Simpson has published tables showing the required spacing for the BVLZ connectors for different spans, loads, and lumber species. The on-center spacing of the connectors ranges from 16-40 inches, depending on the loads and materials.
It’s important to note that the BVLZ is somewhat fussy to install correctly and addresses the vertical loads only, not the lateral load pulling the deck away from the house – a critical point mentioned in a footnote on the Simpson website.
So you would still need to add tension ties or lateral connectors such as the Simpson DTT2 to keep the deck from pulling away from the house. The lateral connectors are required in addition to the BVLZ connectors, a fact that I verified with Simpson’s technical services department. Although the BVLZ connector does not require access from the house’s interior, the DTT2 does. That might require opening up a finished ceiling to access the interior of the band joist. Two of these are required for the ledger on a typical residential deck.
DeckStruc Bracket: A Sturdy Option
Another contender is the DeckStruc Bracket. This are a more rugged stand-off type bracket that requires access to the interior of the band joist. The DeckStruc Bracket is designed primarily for new construction, but can be retrofitted by removing bricks around the bracket and then cutting in new brickwork.
The DeckSturc bracket supports both vertical and lateral loads. Maximum spacing along the ledger ranges from 4 ft. to 5 ft.- 3 in. depending on deck loads.
Band Joist Can Be Weak Link
It’s important to note that both the BVLZ and DeckStuc are designed to attach to a band joist in the house framing. You can’t just put them anywhere along the wall. So your upper ledger, supporting the new shed roof, would need to line up with the house’s second-story band joist.
You also need to consider the strength and integrity of the band joist supporting your new ledger. The goal with these connectors is to transfer the load to the full floor diaphragm, not just to the single band joist. That’s why the code also prohibits ledger attachment to band joists on cantilevers, such as in “garrison” colonials.
For a sturdy connection, the band joist may need reinforcement depending on its condition, orientation, and nailing. This is especially true where the band joist runs parallel to the floor or ceiling joists. If the band joist is not well secured to the house structure, then it becomes the weak link in the system.
Decks vs. Other Structural Ledgers
Since the connectors are designed for backyard decks, not a roof system, you are most likely going to need an engineer’s stamp to get approval from your local inspector, whichever approach you use. Or an engineer may be able to come up with a simpler alternative that would satisfy everyone involved.
Obviously, you don’t want to take chances that the new roof would fail under a heavy snow fall or other excessive load. With backyard decks, it is often heavy snowfall, crowded parties, or large point loads such as hot tubs that are linked to structural failures. It’s not a risk anyone wants to take. In many cases, the component that fails is the deck ledger. There’s a lot riding on this connection, so get it right.