new concrete pads
Do It Yourself
I'm having a pool installed and there
is 5 feet of cement that will surround it. I would like to have the fence to be on the
edge of cement. Because the cement will go in before the fence will be installed, I was
thinking of placing PVC pipe in the cement forms before they pour. What size PVC, depth,
and exact distances between line post? Do you have any other suggestion?
The problem is that I would need to know
exactly what type and style of fence you want to install. Basically though, it is not a
good idea to install forms for proposed fence posts. The problem is that precision must be
used and a slight mistake could throw every hole off. Furthermore, most concrete
contractors don't want to mess with the responsibility of the forms. It certainly would
raise the installation price of the concrete.
Some types of fences are more forgiving of
slight mistakes. Chain link post spacing is not critical except for the location of
terminal posts (gate, ends and corners). Pre-paneled wood could be a problem because the
spacing has to be perfect. You can cut the wood sections to fit, but you can't make them
wider. Also, in order to cut a section, you want to cut exactly where a picket space is or
you will be ripping down pickets. That would not look good with most styles. If you are
building a wood fence from scratch, as long as you keep post spacing below the 8' span of
a 2 x 4, you can always cut them to fit. Ornamental fences and vinyl fences that are made
in sections require exact post spacing. No room for error is allowed with these types.
I recommend placing the fence just outside the
concrete surface so the posts can be set in dirt. It is an easier and therefore cheaper
installation. If you must set the posts on the concrete, core drilling the postholes after
the concrete is poured and cured is the best. An expansion cement is used to set the posts
in the pad. This is easiest on styles with small posts of under 3" diameter, but will
work also on large 4 x 4's or 5 x 5's.
Another way is to mount the posts in special
deck mount fittings. The type of fitting depends on the style of post. These fittings
simply bolt to the concrete and the post fits into the fitting.
Regardless of how you install the posts,
always leave a safe distance from the edge of the concrete pad to avoid cracking of the
pad. 6 to 12" are recommended. Never make a square form or hole through the pad. This
will cause cracking in the pad at each of the corners of your square.
Your question also requests a size for the
form. The form only has to be as large as what will allow the post to fit. That does not
allow for any error to move posts later, if the form was off. Also the hole size depends
on whether you intend to set the post in the formed hole with expansion cement or dig into
the ground below so you can set a full depth fence footer, as in normal dirt
Author: Frank R. Hoover, Hoover Fence
25 years+ in the fence business
Copyright 1999 Hoover Fence Co.
May be reprinted as long as source is acknowledged
copyright Hoover Fence Co. and Hoover Enterprises June 1999
5531 McClintocksburg Rd., Newton Falls, OH 44444 Phone: (330) 358-2335