Home Repair forum - Waterproofing fence posts

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Waterproofing fence posts

Matthew Reed

2006-07-11, 5:25 pm

More on my fence building subject. I live in Oregon, Lebanon, near Salem.
Rains all year. Lots and lots of rain. I'm using pressure treated ground
contact rated 4x4x8' posts. I plan on setting them 2 feet deep in concrete.
Would it be worthwhile to apply any additional waterproofing coating to the
posts before setting them in concrete? What kind of life expentancy can I
expect from these posts set in concrete? Assuming I take reasonable care to
taper the concrete, cap the top, and keep it painted. If they rot out in 5
years, I'll be stuck with rotted posts in concrete that will need to be dug
up, and I'll have several dozen big chunks of concrete that I won't know
what to do with.

JimL

2006-07-11, 5:25 pm

On Tue, 11 Jul 2006 12:23:57 -0700, "Matthew Reed" <nospam at zootal
dot com nospam> wrote:

>More on my fence building subject. I live in Oregon, Lebanon, near Salem.
>Rains all year. Lots and lots of rain. I'm using pressure treated ground
>contact rated 4x4x8' posts. I plan on setting them 2 feet deep in concrete.
>Would it be worthwhile to apply any additional waterproofing coating to the
>posts before setting them in concrete? What kind of life expentancy can I
>expect from these posts set in concrete? Assuming I take reasonable care to
>taper the concrete, cap the top, and keep it painted. If they rot out in 5
>years, I'll be stuck with rotted posts in concrete that will need to be dug
>up, and I'll have several dozen big chunks of concrete that I won't know
>what to do with.
>

Sure. And pile it on thick at the very bottom especially up to
about 4 inches from the surface. (Ugly when it shows).

I've dug up lots of those concrete bottoms with broken posts in them
and it is always VERY hard work, so you are right to do what you can
when planting them.

Bob

2006-07-11, 5:25 pm

"Matthew Reed" <nospam at zootal dot com nospam> wrote in message
news:LLudnav58OROZy7ZnZ2dnUVZ_v2dnZ2d@giganews.com...
> More on my fence building subject. I live in Oregon, Lebanon, near Salem.
> Rains all year. Lots and lots of rain. I'm using pressure treated ground
> contact rated 4x4x8' posts. I plan on setting them 2 feet deep in concrete.
> Would it be worthwhile to apply any additional waterproofing coating to the
> posts before setting them in concrete? What kind of life expentancy can I
> expect from these posts set in concrete? Assuming I take reasonable care to
> taper the concrete, cap the top, and keep it painted. If they rot out in 5
> years, I'll be stuck with rotted posts in concrete that will need to be dug
> up, and I'll have several dozen big chunks of concrete that I won't know
> what to do with.

It has always seemed to me that those metal post holders that you set in
concrete would be a better bet. The end of the post will be able to breath
some, so it should last way longer. Plus, replacement would be way easier.

Bob

Matthew Reed

2006-07-11, 5:25 pm

>
> It has always seemed to me that those metal post holders that you set in
> concrete would be a better bet. The end of the post will be able to breath
> some, so it should last way longer. Plus, replacement would be way easier.
>
> Bob

I'm not sure I've seen these before, but I think I know what you are talking
apart. Do they hold the post securely enough to take the load of wood,
gates, etc. ?

Chris Lewis

2006-07-11, 8:25 pm

According to Matthew Reed <nospam at zootal dot com nospam>:
>
>
> I'm not sure I've seen these before, but I think I know what you are talking
> apart. Do they hold the post securely enough to take the load of wood,
> gates, etc. ?

No. They need side support if they're of any height or significant
side load. Same for "post spikes". Not suitable for fences or
freestanding decks (unless very short).

The trick with concreted fence posts is to bed the bottom end
of the post in several inches of gravel before pouring concrete.
Any moisture entering the post can leave out the bottom, and the
bottom isn't held in direct contact with moisture. PT posts
will last a very long time when done properly.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

HeyBub

2006-07-11, 8:25 pm

Matthew Reed wrote:
> More on my fence building subject. I live in Oregon, Lebanon, near
> Salem. Rains all year. Lots and lots of rain. I'm using pressure
> treated ground contact rated 4x4x8' posts. I plan on setting them 2
> feet deep in concrete. Would it be worthwhile to apply any additional
> waterproofing coating to the posts before setting them in concrete?
> What kind of life expentancy can I expect from these posts set in
> concrete? Assuming I take reasonable care to taper the concrete, cap
> the top, and keep it painted. If they rot out in 5 years, I'll be
> stuck with rotted posts in concrete that will need to be dug up, and
> I'll have several dozen big chunks of concrete that I won't know what
> to do with.

Any particular reason you're not using metal posts? Smaller holes, less
concrete, won't rot, easier to attach rails (they make clamp-like things for
that purpose), easier to replace when something goes wrong (hit by car?).

I don't think you want to PAINT pressure-treated posts.

tlhumm@hotmail.com

2006-07-11, 8:25 pm

Matthew Reed wrote:
> More on my fence building subject. I live in Oregon, Lebanon, near Salem.
> Rains all year. Lots and lots of rain. I'm using pressure treated ground
> contact rated 4x4x8' posts. I plan on setting them 2 feet deep in concrete.
> Would it be worthwhile to apply any additional waterproofing coating to the
> posts before setting them in concrete? What kind of life expentancy can I
> expect from these posts set in concrete? Assuming I take reasonable care to
> taper the concrete, cap the top, and keep it painted. If they rot out in 5
> years, I'll be stuck with rotted posts in concrete that will need to be dug
> up, and I'll have several dozen big chunks of concrete that I won't know
> what to do with.

Just make sure you use enough gravel and keep the posts clean from
debri.
I put PT posts in my house near Portland 20 years ago and there is no
sign of rot at all,
except for one post near a fir tree that was always covered at the base
with pin needles and rotted out after about 15 years. If you install
them so they can dry out after getting wet, the'll last a lot longer
than 20 years.

Matthew Reed

2006-07-11, 9:25 pm

<tlhumm@hotmail.com> wrote in message
news:1152664023.648853.28810@75g2000cwc.googlegroups.com...
>
> Matthew Reed wrote:
>
> Just make sure you use enough gravel and keep the posts clean from
> debri.
> I put PT posts in my house near Portland 20 years ago and there is no
> sign of rot at all,
> except for one post near a fir tree that was always covered at the base
> with pin needles and rotted out after about 15 years. If you install
> them so they can dry out after getting wet, the'll last a lot longer
> than 20 years.
>

20 years is pretty good! Did you set yours in concrete? Where near Portland?
I used to live in Vancouver before moving to Lebanon. Still working in
portland, on 82nd about a mile north of Glisan.

Matthew Reed

2006-07-11, 9:25 pm

"HeyBub" <heybubNOSPAM@gmail.com> wrote in message
news:12b8f6344cn3p6e@news.supernews.com...
> Matthew Reed wrote:
>
> Any particular reason you're not using metal posts? Smaller holes, less
> concrete, won't rot, easier to attach rails (they make clamp-like things
> for that purpose), easier to replace when something goes wrong (hit by
> car?).
>
> I don't think you want to PAINT pressure-treated posts.

Never done it that way, and I already have a bunch of wood posts. Need to
research it, I don't think I've ever seen a wood panel fence with metal
posts.

Mark

2006-07-12, 3:25 am

I've just pulled out about 6 posts that I put in almost 25 years ago. Set
them 2' deep, no concrete and a standard 1x6 'dog ear' 6' tall fence. I was
pleasantly surprised to see that there was NO rot on the posts at all. I'd
never intended to leave the fence up that long once the kids grew, but never
got around to removing it. We're in the centeral Ohio USA area, maybe not
generally as rainy as Portland, but it was very damp where the fence was
located - often got a couple inches of standing water after a good rain due
to poor drainage.

Of course 25 yrs ago we used the 'good old' arsnic preserved wood, not the
stuff they havce today.

"Matthew Reed" <nospam at zootal dot com nospam> wrote in message
news:LLudnav58OROZy7ZnZ2dnUVZ_v2dnZ2d@giganews.com...
> More on my fence building subject. I live in Oregon, Lebanon, near Salem.
> Rains all year. Lots and lots of rain. I'm using pressure treated ground
> contact rated 4x4x8' posts. I plan on setting them 2 feet deep in
> concrete. Would it be worthwhile to apply any additional waterproofing
> coating to the posts before setting them in concrete? What kind of life
> expentancy can I expect from these posts set in concrete? Assuming I take
> reasonable care to taper the concrete, cap the top, and keep it painted.
> If they rot out in 5 years, I'll be stuck with rotted posts in concrete
> that will need to be dug up, and I'll have several dozen big chunks of
> concrete that I won't know what to do with.
>

Matthew Reed

2006-07-12, 3:25 am

My drainage is very good, but in fall/winter/spring it is not unusual to go
for weeks and weeks without a non-rainy day. Anyone know how good the new
posts are? Maybe I need some creosote

"Mark" <mws@junkmail.com> wrote in message
news:Y0_sg.23096$vl5.7018@tornado.ohiordc.rr.com...
> I've just pulled out about 6 posts that I put in almost 25 years ago. Set
> them 2' deep, no concrete and a standard 1x6 'dog ear' 6' tall fence. I
> was pleasantly surprised to see that there was NO rot on the posts at all.
> I'd never intended to leave the fence up that long once the kids grew, but
> never got around to removing it. We're in the centeral Ohio USA area,
> maybe not generally as rainy as Portland, but it was very damp where the
> fence was located - often got a couple inches of standing water after a
> good rain due to poor drainage.
>
> Of course 25 yrs ago we used the 'good old' arsnic preserved wood, not the
> stuff they havce today.
>
>
>
> "Matthew Reed" <nospam at zootal dot com nospam> wrote in message
> news:LLudnav58OROZy7ZnZ2dnUVZ_v2dnZ2d@giganews.com...
>
>

Larry Jaques

2006-07-12, 9:25 am

On Tue, 11 Jul 2006 19:20:45 -0700, with neither quill nor qualm,
"Matthew Reed" <nospam at zootal dot com nospam> quickly quoth:

>"HeyBub" <heybubNOSPAM@gmail.com> wrote in message

>
>Never done it that way, and I already have a bunch of wood posts. Need to
>research it, I don't think I've ever seen a wood panel fence with metal
>posts.

I have, but those were there to support broken wooden posts. <g>

Black locust wood posts with charred ends seem to last forever.
The suggestions to plant the PT post in gravel, then add mounded
concrete on top is a good one.

LJ in Grants Pass, OR south of you guys but still in the PNW.

-
In nature's infinite book of secrecy a little I can read. -Shakespeare
------
http://diversify.com Website Application & Database Development

tlhumm@hotmail.com

2006-07-13, 1:25 pm

Matthew Reed wrote:
> <tlhumm@hotmail.com> wrote in message
> news:1152664023.648853.28810@75g2000cwc.googlegroups.com...
>
> 20 years is pretty good! Did you set yours in concrete? Where near Portland?
> I used to live in Vancouver before moving to Lebanon. Still working in
> portland, on 82nd about a mile north of Glisan.

In Hillsboro. I did set them in concrete and sloped the concrete to
drain the water away.
The whole key is to keep the base of the post clear and use enough
gravel for drainage.
My neighbor put a fence up the same time as me and used Cedar, his
fence is still their, but he is noticing some rot just now. I wouldn't
worry about rot using PT lumber at all. Just install them right.

Bob

2006-07-17, 5:25 pm

"Chris Lewis" <clewis@nortelnetworks.com> wrote in message
news:12b8a2s5r3utd40@corp.supernews.com...
> According to Matthew Reed <nospam at zootal dot com nospam>:
>
> No. They need side support if they're of any height or significant
> side load. Same for "post spikes". Not suitable for fences or
> freestanding decks (unless very short).
>
> The trick with concreted fence posts is to bed the bottom end
> of the post in several inches of gravel before pouring concrete.
> Any moisture entering the post can leave out the bottom, and the
> bottom isn't held in direct contact with moisture. PT posts
> will last a very long time when done properly.

Depending of course on the water table. They'd be in the
water all winter where I am.

Bob

Matthew Reed

2006-07-23, 5:25 pm

>> The trick with concreted fence posts is to bed the bottom end
>
> Depending of course on the water table. They'd be in the
> water all winter where I am.
>
> Bob
>
>

It rains all fall, winter, and spring, but the water table stays down 6-8
feet or so. I think I'd be safe with a 30 inch hole with 6 inches of gravel
at the bottom. Maybe less gravel.

timhirshorn@gmail.com

2006-07-24, 1:25 pm

With all the success everyone has had, I hear that your using PT posts.
Did you also add water repellent to those post? I live in Seattle and
get lots of rain. I am installing the PT posts as reccomended (gravel
at the bottom and in concrete) but am conteplating the time/cost/effort
of applying the water repellent to them first.

Thanks!
Tim

Matthew Reed wrote:
>
> It rains all fall, winter, and spring, but the water table stays down 6-8
> feet or so. I think I'd be safe with a 30 inch hole with 6 inches of gravel
> at the bottom. Maybe less gravel.

timhirshorn@gmail.com

2006-07-24, 1:25 pm

Matthew Reed

2006-07-31, 3:25 am

I'm not that far south from you, maybe 90 minutes south of Portland. Do you
have any more info on water repellent treatment? I'm using PT posts rated
for ground contact (very important - they can't be just PT, they have to be
rated for ground contact). I don't want to have to dig up 3 tons of concrete
10 years from now when the posts rot out.

<timhirshorn@gmail.com> wrote in message
news:1153757616.090151.179040@m79g2000cwm.googlegroups.com...
> With all the success everyone has had, I hear that your using PT posts.
> Did you also add water repellent to those post? I live in Seattle and
> get lots of rain. I am installing the PT posts as reccomended (gravel
> at the bottom and in concrete) but am conteplating the time/cost/effort
> of applying the water repellent to them first.
>
> Thanks!
> Tim

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