What is the best practice for building a new wall on top of concrete to create a bay window, should we pour a concrete curb or use sill flashing under the framing?
Asked by Susana Tapia 
2 months ago
Last Updated: November 6, 2024
Hey there! So, my husband and I are tackling a home renovation project where we’re turning our garage into a bedroom and making the garage door into a bay window. We’re planning on raising the floor by 11 inches and keeping the existing garage door header. The bay window will go from the ground to the soffit and sit directly on the concrete, which slopes slightly away from the house on our front porch.
We’re a bit unsure about whether we should raise the framing onto a concrete curb or use sill flashing (break metal) to prevent water damage. Any advice on the best way to go about this? We’d really appreciate your expertise on this matter!
Remember that the bottom plate must be treated. You can secure it by using a ramset, or by drilling and screwing it with tapcons.
If you find an engineer, have a chat with them. Chances are they will need to approve your permit before it’s finalized.
There is a thin foam piece that should be placed on the concrete before installing the bottom plate.
Make sure to obtain a permit and review the regulations for your specific city, state, or town. Each location has different requirements that need to be followed.
I’m also curious about permits. Concrete is a warning sign.
Just wondering, why is concrete considered a red flag to you, Christine?
Hey there! If you’re thinking about making changes to your HVAC, drainage, or foundation, just know that different rules may apply depending on if you live on a 5-acre parcel or in the city where neighbors can be nosy. You can always ask questions and get in touch with a local contractor for advice. It’s also a good idea to chat with a friend who’s on the township board or a local building inspector for more guidance. Sometimes you might be tempted to skip getting a permit, but trust me, it’s best to play by the rules and avoid any surprises later on. It’s possible that some work will need to be done by a certified professional or just require an inspection. Sometimes you might even have to backtrack a bit. Just keep that in mind! 😬
What are you talking about, ? 🤔
I’m just sharing my experience as a resident and homeowner working on expansion and remodeling projects in a rural farm community. Can’t say I know much about city life!
I actually understand most of it now that I’ve read it again. The first sentence was a bit confusing at first. Permits are really important for homeowners and DIY-ers to make sure their project meets safety standards. The inspectors in my area are knowledgeable and easy to work with, but having to go through the inspection process does slow down the project a bit.
As shared, in her experience as a homeowner and remodeling business owner in a rural community in Southern West Virginia, people tend to avoid permits and resist government regulations, constructing without restrictions and challenging anyone who raises concerns.
You can attach it directly to your slab. The foam mentioned is called sill seal, which doesn’t actually seal but creates an air barrier between the pressure-treated plate and concrete. Pressure-treated wood on concrete can lead to moisture, and the sill seal allows for airflow. Frame and sheath your wall, then flash between the sheathing and siding.
It’s okay to go straight to the slab with a sill barrier. Keep in mind the permit comments depending on your location. Personally, I recently completed a 400 sq ft cabin, built a new deck with a pool at my own home, and added two bedrooms without permits or inspections. Enforcement is limited in our area, especially further away from town. People rarely sell their homes here, so resale value isn’t a big concern. I wouldn’t seek advice from a real estate agent for that reason.
Insurance companies, like mentioned, will search for any excuse to deny your claim in case of an incident.
I placed one last year on a curb to match the existing brick ledge. It was a new experience, so I did a lot of research. In the end, I found that making a kerf cut to embed the flashing made both the customer and myself feel the most comfortable and satisfied. Matt Risinger has a video on the process: https://youtu.be/pieezQpcDsg?si=8Vn2ewDwN1ZDvUt
Any chance you could share some photos?