How can I build a privacy fence?

Question

I'm about to install a privacy fence around a decent sized area of land, both for privacy and to keep my 3 year old daughter and our two basset hounds safely away from the road.

I'm installing the fence with 6' pickets on the back and 4' pickets around the rest of the yard. I was wondering:

• if there was a general guideline for the spacing of the 4x4 posts
• how tall the posts should be in relation to the picket height
• how much of the 4x4 post to put into the ground and cemented in
• any other advice from people with experience?

I also was curious as to how to install a gate that would be wide enough to drive a riding mower through but not sag on one side and dig into the ground.

Answer 1

Eight feet is a common distance between posts, due to it being a standard lumber length. You will have a stiffer, longer lasting fence at 6-7 ft. An integer number of pickets with your desired spacing is a good way to decide from a design standpoint.
I prefer to sink posts to at least frost level (42" in my area). The 1/3 advice is good if frost is not an issue.

I also prefer crushed gravel (21AA or paver base) to place wooden posts (versus concrete or pea gravel). 3-4" in the bottom of the hole (beneath post), continuing up the sides of the posts to just below the surface. Give the post a push after first 5" and tamp along all 4 sides as you fill. This technique will greatly extend post life and minimize rot.

I've used the gate brackets that you build into the gate which have hinges built in. They will stabilize a 42" gate (each side). Extra long screws on the top hinge are helpful. Stainless steel cable run diagonally (with adjustment turnbuckles) run from the top of the hinge to bottom of the gate (at the opposite corner) will make it sag proof.

Disclaimer 1 user of product, no financial connection:

Disclaimer 2: Haven't used it but sounds interesting, YMMV (Near) Instant fence post backfill

Answer 2

if there was a general guideline for the spacing of the 4x4 posts

6 and 8' is common. 4' not unheard of, though less common.

how tall the posts should be in relation to the picket height

That's really an aesthetic call on your part. Whatever looks good to you.

how much of the 4x4 post to put into the ground and cemented in

The rule of thumb is that you want 1/3 of the post in the ground. So for a 4' post above ground, you want 2' below.

any other advice from people with experience?

You don't necessarily want to cement the posts. Alternatives are packed soil, or crushed rock. The arguments are that cement can act like a sponge and trap water, and that crushed rock allows it to drain. But it also depends on the environment you are building these in.

THe other advice is that I'd go with Cedar posts rather than pre-treated. I've had problems with pre-treated posts warping and checking like crazy as they dry out over the years.