I'm building a cat climbing wall, and plan to have a series of large "pegs" as steps. My plan is to use 1-foot lengths of landscape timber (basically a 4" diameter log) and attach directly to the wall studs using one 3/8" x 3" dowel screw for each peg. All shelf brackets I've seen have a lower support brace and more than one screw connecting to the wall, so I'm slightly concerned that one screw won't be enough to support the cantilevered weight of a cat (~15 pounds, plus dynamic forces). Is this realistic, or will the screw pull out, or will the log put too much pressure on the drywall, or any other reason why this would be a bad idea? Should I just put the screw off-center toward the top of each log so there's more of a lower brace, or use bigger dowel screws, or will I need a proper shelf bracket to support the peg?
- the screws are at least 1/4" in diameter
- they penetrate at least 1" into the stud
- the timber ends up snug to the drywall
... this should work fine. The key is that installation leaves the timbers with no gap to the drywall that would allow movement. If there's room for movement, the drywall will eventually be damaged and the screws could work loose.
Yes, it would do to install the dowel screws closer to the top of the timber, say 1" down, to reduce pressure on the lower edge of the cut. You might put waxed paper behind the timbers while you thread them in to act as a lubricant and to protect the wall.
You could simplify matters by installing each timber segment on a backer board (say a 16" segment of 1x6) using three or four 2-1/2" screws, then simply mount those to the studs over the drywall. The torque load on the timbers would be transferred to and distributed by the backer boards rather than through drywall, which is quite soft.