As a structural engineer, being presented with an opportunity to provide some thoughts on kitchen and bath design made me scratch my head for a moment, but it was a short moment. Suddenly, years of design issues related specifically to kitchen and bath remodels came to mind. Kitchens specifically are such an important room in modern American culture. We’ve seen an evolution from the small, closed-off designs of the past to more socially functional designs that embrace the fact that no matter what other awe-inspiring rooms there may be in the home, the kitchen still ends up being the one place where almost everybody gathers. Having a kitchen that connects seamlessly into adjacent spaces is a key component of most modern residential designs.

It is very common for kitchen remodels to include removing walls that isolate the kitchen from other spaces. It’s also very common for these walls to be load-bearing in two-story construction, and even in single-story construction prior to the mid 1970’s or so. When considering the cost of your remodel, be sure to have any walls you’d like to remove evaluated to determine if they are load-bearing. If they are, a new beam and columns will be required to support the structure once the walls are removed. In addition, the structure below needs to be evaluated to determine if it is adequate to transfer the new loads to the foundation.

Reworking the layout of a kitchen also frequently involves relocating or adding exterior windows and doors. Needing a new beam/header over the new opening is pretty obvious, but depending on your existing exterior wall configuration, the change might also require reinforcing the remaining walls to strengthen their ability to act as shear walls. This could require the installation of plywood or OSB panels on the interior face of the walls, as well as hardware to reinforce the connection of the walls to the foundation.

Rerouting plumbing and electrical also becomes an important consideration. Moving the sink, dishwasher, refrigerator, etc. to a new location may mean you are going to have to open the ceiling in the room below the kitchen or take up portions of the kitchen floor to run new plumbing and possibly electrical as well. Relocating heating/cooling floor registers (and the ductwork serving them) also becomes a likelihood. Moving the oven means the ducting for the hood is going to move too. Very quickly, the remodel that was intended to focus on the kitchen and maybe one adjacent space impacts adjacent portions of the home all around the kitchen, and costs to repair wall, ceiling, and floor finishes escalate the overall cost of the remodel. Strange things occur sometimes when an inexperienced plumber or electrician needs to run new lines. In one project we saw a plumber cut a three-inch-wide by six-inch-tall notch out of the bottom of about twenty 2×10 floor joists so that he could run the new kitchen sink waste line. Obviously, he won the opportunity to run the line using a different route, and to get a lesson in floor joist repair. With respect to bathrooms, zero-entry showers and linear drains present another chance to damage floor joists while also increasing the load on the floor system.

Another consideration that is frequently overlooked is checking to make sure that the existing floor joists are adequate to support new heavy loads imposed by solid-surface countertops such as stone or concrete, as well as custom or commercial appliances that may weigh several times as much as the typical residential counterpart. The code requirement for residential floor design is 40 pounds per square foot (psf) for live loads (loads imposed on the floor by occupants and their furniture, etc.). Dead loads for residential floor systems commonly range from 15 to 20 psf. A large kitchen island with a heavy solid-surface countertop can exceed 20 psf and can potentially cause a noticeable sag in the floor. A particularly heavy appliance might require floor reinforcement below the appliance feet to prevent the floor sheathing from sagging, potentially causing tile to crack or hardwood to split.

Almost all the issues mentioned for kitchens also apply to bathrooms and laundry rooms. One special consideration for remodels involving laundry rooms is the placement of the clothes washer. The popularity of high-efficiency washing machines with horizontal axis drums has introduced a new common problem. These machines frequently cause vibrations in the supporting floor that impact adjacent spaces. Consider using single-span floor joists or trusses in the laundry room, so that vibrations are less likely to be carried by the floor joist to adjacent rooms. Plan the laundry location so that vibration-sensitive living areas are not impacted. Having the laundry on the second floor next to the master suite might be convenient, until the washing machine goes into the spin cycle at 1:00 AM and the vibrating floor converts the bed to a Magic Fingers experience.

Be careful not to make a decision you will later regret. Don’t allow your structural engineer to put a column in a location that is going to bother you as long as you live in the home, regardless of the cost savings. Don’t put in a beam to support the ceiling in a “dropped” (below the ceiling) configuration if it doesn’t work with your floor plan. There have been many conversations along the lines of “I knew I wasn’t going to like that,” which later require an explanation every time a friend enters the remodeled area for the first time. Plan for the future if you are able to do so. If there is a reasonable chance that you will be in the home through retirement, consider providing accessible pathways, especially in the bathrooms and master suite closet(s). 

Lastly, expect the unexpected. While remodeling our current home, originally built in 1904, we have found newspapers from the 1950s that were used as insulation; baby shoes, toys, letters, and old photos in the spaces between floors; and 2×4 floor joists on the second floor that span twelve feet. Everything but that last item was an exciting find that added emotional value to our home. The last item provided another opportunity to add value to our home, just in another unexpected way. Every project should have funds allocated for contingencies.