Corian counter support

Old 01-13-24, 08:16 AM
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Corian counter support

As part of a bathroom remodel I am having a laundry niche created for undercounter washer and dryer. The niche will be four feet wide with a Corian countertop installed above the machines. The counter will be supported on wall cleats at the two ends and the back. I expect that the counter needs additional support across the front to prevent the Corian from sagging or cracking. The Corian is 1/2 inch thick with an additional piece across the front to create a 1 inch thickness.

My contractor is suggesting a 1.5" x 1.5" steel angle across the front (behind the finished lip) for added support however that means that the steel will protrude 1" below the counter thickness into the space for the machines, so I would like an angle or channel with a 1/2 to 1 inch leg.

How can I calculate the size needed to support the 48" x 30" counter at the front with possibly an occasional 150-200# load (person sitting/standing on the counter) at the center?

In a previous project I had 1/2" x 3" steel cantilever channels installed in the particle board infill of a Corian counter to support a 14 inch overhang but they were perpendicular to the edge and supported by cabinets below. In the current case there will be no support from below and the support is at the ends.

Your suggestions will be appreciated. Thanks.
Old 01-13-24, 09:39 AM
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To calculate what you want you need to know how much deflection you can tolerate and under what load. The Corian can support itself over that distance but if you were to sit on it it likely would break. So, do you want to support a 30 basket of laundry or a 250 pound man standing on the counter to change the ceiling light bulb? I personally like square tubing because it has two vertical sides to provide more strength versus the one vertical that angle material has. You can also use C channel laying down so the two sides become your verticals for strength.

You can go to a steel fabricator or welding shop and ask to look at the material they have in stock. (It doesn't hurt to have a six pack in your hand.) Set some blocks on the floor 4' apart and lay a piece of material down and stand in the middle. Then you can try different sizes of square tubing, U channel and angle to see what provides the stiffness you want. Also note that most materials are available with different wall thicknesses so you can have different strengths from the same external dimension depending on the wall thicknes.

When I redid my kitchen I had about 5' of granite counter that needed supporting. I used 1 1/2" square tubing with 1/4" wall thickness. That provided two, thick vertical sections of steel over the one that using angle would provide. I painted it black and installed it back from the front by about 4" so it is less visible.
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Old 01-13-24, 04:03 PM
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You could also use one or two of the brackets made to support floating countertops, such as this one:

It fastens to the side of the stud inside the wall (so requires some sheetrock work), but there are other styles. A search for counter top support brackets will give you lots of options.
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Old 01-13-24, 04:23 PM
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Anyone who steps foot on a countertop like that should be punished. Severely.
Old 01-14-24, 07:00 AM
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should be punished. Severely

This is the latest of several issues the has my wife thinking that our architect is aiming for a project that will survive the dumbest housekeeper ever.

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