I am interested in sprucing up my backyard fence without completely putting in a new fence. I would like to use horizontal wood planks and attach them to my existing vertical fencing? Is this possible and what materials should I use to best achieve this goal?
I would need to know more about the existing condition of your fence. If you could send me a picture that would be great. I would definitely recommend that your existing fence be in very good shape if you were going to add on to it. If it were old and rickety it wouldn't do you a whole lot of good to put new materials on top of it that's for sure. There's a lot of things to consider. Are you a fasteners I.e. your nails or screws coming loose on your fence? Is the wood rotted or warped? All that stuff makes a big difference in what you are asking. Another thing that is very important is your 4x4 post that are in the ground if they are loose I certainly would not add more weight to the fence. I would hope they were set in concrete from the beginning If they weren't I wouldn't even consider doing this.
You can install horizontal fence boards over vertical, but as mentioned already the existing fence and it's frame work must be sound and in sturdy condition especially the upright posts and horizontal stringers. Depending on the size of the new "planks" (I'm guessing this means a 2 x 6 or 8?) and more importantly their length you may need additional posts. Most fence posts are installed at 8 foot (+ or -) intervals , but not all. You will need to measure the new boards lengths and then check the fences posts spacing to be sure each end of the board can be fastened to a post. If the boards length is 16 feet you can screw a 3 inch deck screw at 3 locations. Also cut each board to install on the center of each post. That way the next board butting against it has half a post to attach to. If your new boards are not long enough to span 2 posts (or 3), you may need to install more posts so as to accommodate the boards length or cut them down to the center of the next post.