Mounting Wood countertop to top of a short wall

[cody michael]

I Built an ash counter-top for some friends of mine.

They cut out a wall separating their living room and kitchen, counter-top will be a bar counter type idea.

There is a 2x4 screwed to the top of wall (should I replace this with a 2x6 cut down to 4.5 inches to give me a little more wood to screw to?), my plan is to take some 1/4 inch by 2 in wide steel. Screw it to the top of the wall, then screw up into the ash (using either a slot or over sized hole in the steel to account for movement of the ash). it is about 9 ft long, I was thinking 4 pieces of steel would that be sufficient? The steel would go out close to the edge of the over hang (11 inches from the wall).

Is there a better way to do this?

most of it is about 19 inches wide, how much will ash expand-contract over 19 inches?

[Jim Becker]

I've used the steel to reinforce things like that and actually will be doing that on a new commission to help support the end of an island top that will have greater exposure as an eating bar. I suggest you recess the steel into the wood top, however, so that there is still full contact with that wall support. Additionally, can you hide some steel angle along the edges of the wall on either side to widen the wall support area?

[John K Jordan]

Cody, I don't quite understand the design and support needs and how you would use the steel. Would the steel strips be lying flat? If I'm imagining it correctly I'm wondering how much support that would give. Even 1/4" flat steel laid horizontally can be a little flexible but worse, significant downward force on the end could pull the fasteners out of the end. (What if someone tries to sit on the top?) Cantilevered steel channel or angle iron is a lot stiffer and stronger than flat steel plate.

I did use steel supports on a countertop on an narrow short wall. In my case it was an 18" countertop with granite on top extending almost a foot from the wall. Just over 6' long. I didn't want diagonal braces to show or get in the way of stools or knees.

I built a wood frame around two layers of 1" oak plywood to go under the granite I welded up four steel supports from channel for support and embedded it into the frame. Each support has a leg that bears horizontally against a long steel channel embedded into the wall. (I was worried someone would pull or sit on the edge and crack the granite.) I fastened the steel supports to the frame with heavy lag screws and used bolts as adjusters to make the top of each support perfectly level. All the steel was hidden.

I don't have the best photos of this but this is what I have:

As when we bought the house (the before picture), a rendering of the support, the support in place while I was building the kitchen, and the counter installed (but the wall not yet finished.

371136 371137 371138 371139

I don't know if this any of this would apply to your situation since I did not have to deal with wood movement but I can say it is probably strong enough to dance on and has no issues after a dozen years.

JKJ

[cody michael]

I had a 2 inch wide piece of angle about 6-8 inches long, I tried to bend it using some 12inch long channel locks, so about 16inches of leverage, It only deflected maybe 3/16. I know they do not want stuff hanging below the bar, I could go a little wider maybe 3 inch flat stock?. The counter will be to high for someone to sit on. only thing I am concerned with is a heavier person pushing themselves up off it. I could also use more pieces of steel, 5 or 6 etc. I was going to notch the 2x4 so the angle is recessed into it, I might also need to put a 1x4 on top of the 2x4 to build it up a little more.

I'm not sure how angle iron would work, that would be a good way to strengthen it. If it was my house I would do that and weld it together, but I don't have much time to mess with the brackets, it is going up next week.

[Jim Becker]

Remember to account for wood movement when you fasten the steel to the planks if the steel goes cross-grain. ;)

[John K Jordan]

I had a 2 inch wide piece of angle about 6-8 inches long, I tried to bend it using some 12inch long channel locks, so about 16inches of leverage, It only deflected maybe 3/16. I know they do not want stuff hanging below the bar, I could go a little wider maybe 3 inch flat stock?. The counter will be to high for someone to sit on. only thing I am concerned with is a heavier person pushing themselves up off it. I could also use more pieces of steel, 5 or 6 etc. I was going to notch the 2x4 so the angle is recessed into it, I might also need to put a 1x4 on top of the 2x4 to build it up a little more.

I'm not sure how angle iron would work, that would be a good way to strengthen it. If it was my house I would do that and weld it together, but I don't have much time to mess with the brackets, it is going up next week.

Seems like 3/16 deflection in 6" is a lot. While angle iron can resist deflection better than flat plate it would probably require welding for the best strength. However, most angle iron 2" on one side is also 2" on the other side. Angle iron also comes in a variety of steel thicknesses - I have some that is 1/4" thick.

Shallow channel can be stronger than angle iron (since it has double angles on the sided) and definitely stronger than flat bar the same thickness, but it does probably need to but fabricated by cutting and welding.

If using flat bar with no welding, thicker would be better than thin. I might get a 90-deg leg bent on the end at a fabricator or bend it myself with a hydraulic press or after heating with an oxy-acetelyne torch. That way a vertical leg could be fastened to the face (or the back) of a support board in or on the wall to provide extra support against leverage. Too bad you don't live here - we could make something in an hour or two from steel stock in my shed. (Years ago I bought 8000 lbs of steel stock at scrap prices and have been using it since.)

If you can't hide it flat bar fastened to the underside of the slab could look better than other options. If one end is against the side wall it could be supported there too.

For a 9' length I would consider using more pieces of steel. I decided to make four strong brackets to support my 6' counter.

JKJ