Renovation efforts are ongoing in our humble abode. Last week, we engaged into the largest part of our indoor project as yet and replaced our kitchen window. This entailed also taking down the old divider wall between our too-small kitchen and our wasted-space back entry. We live in a modest 960 sq.ft. bungalow that was built in the '70's. And like most houses built at that time, our home consists of multiple, divided, interior spaces. We are well on our way to changing that.
As our kitchen took a big reno hit last week, it sparked our conversation again to taking out the center wall and the new kitchen plan. Currently, there is an 'L' shaped wall dividing our kitchen and living room. Original inspection of the house structure indicated that the trusses, running across the width of the house, would be able to easily withstand taking the centre wall out without any sagging or structural concerns.
After further inspection and in conversations with our neighbours, some of whom had ventured down the same path, we have discovered that we seem to have, call it, 'first generation' trusses. Let me explain.
Roof Trusses: The Old and The New
Trusses are the structural 'triangles' that hold your roof up and carry the bulk of the load across the width of the house to deliver the stress down through the walls and ultimately into the ground via the foundation. To give you an idea of what a truss looks like, here is a basic diagram:
The top and bottom chords transfer load across to your walls. Occasionally, there is a supporting wall somewhere along the bottom member, usually near the centre. Trusses today are typically built with a positive camber (upward lift) in order to account for the loaded weight on the truss, and allowing the truss to sit level once fully loaded.
Now, we are not in a structural member class nor do I expect you to learn all this in explicit detail. Why I'm telling you this is to explain what we found. So called 'first generation' trusses were built level, meaning, there was no positive camber introduced at the build stage. This means that the truss sits level right from the start, BEFORE taking it's full load. The wall dividing our kitchen and living room is not a true structural wall, meaning the roof will fail under full loading (think big snow fall) without it, but it is a supporting wall, meaning it takes part of the stress in the truss and transfers it down to the beam in the basement and ultimately to the foundation and ground.
So, in order to keep our roof from sagging (gravity can be a jerk sometimes), we realized we would need to add a structural beam on our main floor. And here was the rub:
To add a beam, most likely we would need to add a column.
We have approximately 20' of clear span (open space) from the centre wall running through the one half of our house to the outside wall on the other side of the kitchen. For those of you who have retrofitted older homes, you understand that structural columns NEVER sit in the best location. But what to do? We don't want our roof sagging in!
Striding in to save the day: structural lumber. As I spent part of my professional career selling structural lumber (also known as engineered lumber), I knew that there was a good possibility we could find a member large enough to bolster our roof WITHOUT the need for a column.
The down side?
A structural beam would have to be quite hefty to span the distance, adequately hold up the limited weight from the roof and do so without a supporting column part way through. So we went to the drawing board. And here's how it would potentially look:
Ignoring the kitchen (which is still in design phase), the beam shown is nearly 12" in height and just over 5" wide. This would allow a fully supported load without a structural column. However, here was the alternative:
With the column, yes we keep a bit more height in the living area, approximately 2-1/2", but then we have this awkward column sitting in the middle of everything and really messing with the plans for the living space.
Thankfully, and I am ever grateful for him, my amazing man decided that we could do without the 2-1/2" of additional headspace (which would still only bring the bottom of the beam to skim the 7' mark) and consequently, have an open, column-free living space. This means that our kitchen design can be much more fluid, our traffic patterns are not hindered by a structural member and our sight lines remain far more open.
What To Take Home From This...
What you can take home from this is a better understanding of how some of the structural members in your home work. If you are looking at, or are currently undertaking, a renovation in your own home, be sure to ask lots of questions about how things can be done. It is also important to bear in mind that, at times, what we truly want simply cannot be done without a large additional cost. Thankfully, our home is not too large and our roof trusses support most of the load. However, in larger homes, or those with a second story, this would not be possible without significant bracing or the need to go to a steel beam. Those become very costly very quickly and most often need to be lifted in place with machines.
If you are already working with a designer, ask her or him to investigate these questions and scenarios for you. While this is not typically a designer's part of the project, it does have a ripple effect on the planning for the rest of the house.
Have questions regarding your own renovation? Post them in the comments below and perhaps I can help, or others in the Dutch Touch community can assist. We love to see you create your own beautiful, personal spaces!