Fit the Top First

Once you´ve got the top fitting nicely, you´ll have to cut the bottom to length. I will say that, depending on the length of your piece and your landscaping, you might have to shorten the corner just enough so that it can be put in place while you´re getting the top to fit properly. Just try not to cut too much off. Once the top fits, you´ll make the bottom cut.

Trimming the Bottom of the Post

On the bottom, you want to make sure that you are as low as the existing siding, and perhaps a bit lower, ¼" maybe.

Where to Nail

Now use your 4´ level and place in along both faces of the outside corner. Make sure the corner is snug against the house and that it makes a nice 90 degree angle on the outside corner. With vinyl, it is easy to distort it´s shape, so watch this carefully. Remember what I said about trying to make the corner perfectly level if the house is real bad off. If it is just a little out, you can adjust the corner a bit, but don´t try to do too much.

Try to have someone hold the corner securely, without warping it or moving it around, once you are happy with it´s location. Then place a nail on the top most slot, at the upper end. This is so that the corner will not be able to go any lower than that point. Sink the nail until it stands about 1/16" out. You don´t want it sloppy, but not tight either.

Now nail the bottom slot in a similar fashion, only nail towards the center of the slot. Remember to keep it out about 1/16". Nail the other side in this same fashion, on the top and on the bottom.

Nailing Schedule

Now nail about every 16 inches, being sure not to over drive the nail. On corners, I like to use long nails, like 2". This is to insure that they are hitting the framing. And make sure to keep the corner straight as you nail, don´t bend it.

Tips for Inside Corners

You´re going to be doing basically the same thing as for outside corners, only you want to keep the nailing tabs in their natural position as much as possible. I like to nail one side down first, and then the other.

Don´t Nail as You Go

I´ve seen some installers put a couple of nails in a corner at a time and side up some, then put some more nails in the corner and continue as they go up. I highly discourage this, it tends to leave you with crooked or warped corners. If you are having to use scaffling though, on a very high structure, at least nail up as high as you can reach. In most cases, this will be more than 75 percent of the corner anyhow. For the next corner.