How not to ruin a kitchen remodel

Some design changes introduce engineering challenges
(Image by Barry D from Pixabay)

Kitchens are such an important room in modern American culture. We’ve seen an evolution from the small, closed-off designs of the past to socially functional designs where 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-1970s. In these cases, 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.

The most cost-efficient method for replacing walls with beams is to locate the top of the beam below the framing that it will support. The beam is then wrapped with a finish, and it hangs below the ceiling. This is more likely to be aesthetically acceptable if there is a change in function between the two rooms.

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Reworking the layout of a kitchen also frequently involves relocating or adding exterior windows and doors. Depending on the existing exterior wall configuration, remaining walls might need to be reinforced 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 is also an important consideration. Moving appliances or sinks to a new location may mean opening the ceiling in the room below the kitchen, or taking up portions of the kitchen floor to run new plumbing and possibly electrical. Strange things occur sometimes when an inexperienced plumber or electrician needs to run new lines. In one project, we saw a plumber cut a 3-by-6 inch notch out of the bottom of about 20 2-by-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.

Another consideration that is frequently overlooked in remodels is making 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.

Eric Hanson is founder and president of Anchor Engineering. He can be reached at [email protected].

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