Wednesday, May 4, 2005

Strengthening half-wall, adding countertop an easy project

By TIM CARTER
Tribune Media Services

Q. I recently cut away the top half of an interior non-load-bearing wall so I could open up the space between two adjacent rooms. I plan to put a countertop on top of the new half-wall so we can use it for eating and a conversation center. But the one end of this half-wall is now very flimsy and rocks back and forth. How can I strengthen it, and how do you attach the wide countertop to this thin half-wall so that the top does not flip when someone leans on it? — M.S., Richmond, Va.

A. It is easy to understand why the end of the half-wall wobbles. Before you cut the original wall, the top of it was securely fastened at the ceiling. I am quite sure slight or moderate force at this point will cause the half-wall to bend over to the floor.

If the floor beneath this half-wall is a traditional wood floor system and you can access the underside of the wood floor via a basement or crawlspace, you may be able to remove the wobble in the half-wall in less than 30 minutes.

If you add one 2-by-4 stud to the end of the half-wall, making sure this stud passes through the wood subfloor and is long enough to extend to the bottom of the floor joists below, nearly all of the wobble can be removed. This long 2-by-4 needs to be bolted directly to the half-wall above the floor as well as to the side of a floor joist or to solid-wood blocking that’s placed between two floor joists.

It is important for the bottom portion of this stud that is below the level of the floor to be secured at two points to the floor joist or the solid-wood blocking. This double connection method minimizes rotation of the stud as a person pushes against the top of the half-wall.

If the floor is a concrete slab or you are unable to gain access to the underside of the floor, you have to strengthen the half-wall from above. This can be done a number of ways, but I prefer to add a second, short wall that is oriented at 90 degrees to the half-wall.

This short wall needs to be faced on both sides with 3/4-inch-thick plywood that is screwed to the short-wall studs. This wall also needs to be securely bolted to the half-wall. Do not nail it, as over time the nails may work loose. When you securely bolt this short wall to the floor, you will be amazed at how stiff the half-wall becomes.

Securing a countertop that is perhaps 20 inches or even 24 inches in width to a half-wall that is only 5 inches or 6 inches wide is asking for trouble. As you know, it is impractical to bolt the countertop to the half-wall from the visible finished side of the top. The connection must be done on the underside of the top.

Many builders and designers use decorative brackets to help support the top and offset the downward rotation that happens when a person pushes down against the edge of the top. I am not a huge fan of these brackets for a number of reasons. For starters, they can get in the way of the knees of people sitting at stools as they eat or drink at the top. Some brackets can detract from the sleek look of the half-wall and the countertop.

One method that has worked well for me is to use a piece of flat 1/8-inch-thick plate steel that is screwed and bolted to the top of the half-wall. I prefer to order steel plate that is 4 inches less in width and length than the finished countertop. The short wall at the end of the half-wall becomes an ally when you use this steel support plate. When the steel plate passes over this short wall and is secured to it, it is very difficult to twist the steel plate farther down the half-wall.

Holes drilled in the steel plate allow you to place screws through it into the underside of the countertop. If the countertop is one that will not readily accept screws — such as natural stone, manmade stone or a solid surface material — then use epoxy to adhere the countertop to the large steel plate.

The other advantage to using the steel plate is the extra strength it imparts to the finished top. If your countertop is made from natural stone, the steel plate prevents cracks that may happen if too much weight is placed at the edge of the countertop.