Installing PT Posts In Ground - Building & Construction - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction


Thread Tools Display Modes
Old 08-02-2009, 09:02 PM   #1
Join Date: Aug 2009
Posts: 1
Rewards Points: 10

installing PT posts in ground

for building my deck, I am looking at putting the pressure treated posts directly in the ground. To give them some added protection, I am thinking of coating them with automotive undercoating, and/or wrapping them in something waterproof before they go in the ground. My question is, does the pressure treated wood need to be able to rid itself of the moisture it contains when you buy it, and would my plan prevent it from doing so, thereby causing more problems? Or would this be a good idea, and help the PT wood to last even longer?


deweydomer is offline   Reply With Quote
Old 08-03-2009, 05:56 PM   #2
Join Date: Dec 2008
Location: Western Arkansas
Posts: 323
Rewards Points: 250

I recently ask a similar question here concerning coating PT fence posts with tar. The consensus was not to do it. The wood does need to shed water and coating it will prevent that. There were different opinions on whether to use concrete around the post for the same reason. Some said it was okay and others claimed it would hasten rot. Those against cement recommend setting the posts in gravel. Both under and around the posts so they would always drain. I wasn't comfortable not using concrete so my final decision was to use concrete but to set the posts on 6 inches of gravel and try to slope the concrete away from the post while wet.


Mike in Arkansas is offline   Reply With Quote
Old 08-03-2009, 07:48 PM   #3
Household Handyman
Join Date: Feb 2009
Location: Albany, Ga.
Posts: 2,478
Rewards Points: 1,408

I don't know what type soil you have, around here we have a lot of red clay soil and some sandy soil. I always use gravel in the bottom of a hole for PT and then concrete (bag mix) around the post. I do finish the mud off just a little above grade and slope it away from the post for rain drainage. My 2 worth, David
Thurman is offline   Reply With Quote
Old 08-05-2009, 12:12 AM   #4
Join Date: Jun 2009
Posts: 41
Rewards Points: 25

Most important i think is to get the proper post. Not just a treated post, but one that is treated for underground.

In treated lumber you can get differant treated types. just regular treated lumber is good for above ground, then the other type is good for below ground. Just ask at the lumber store (not a big box....they think treated is all the same usually...)

Sometimes the posts for the undergournd treatement have small holes in them or 'stampings" to make the treatement go in deeper.

Best bet is to go to a real lumber store and ask there.

Like the previous posters said, if you use concrete, make sure to put gravel in the bottom of the hole first so the post can drain, then add concrete after ( mix the concrete then pour into the hole...dont do what some do and just add the mix dry to the hole, as it is not as strong if it is not mixed well).

even better way to do it, use deck blocks or pour cement piles and put the post on top of those--then you dont have any issues at all with rot (post out of the dirt).
rahfiki is offline   Reply With Quote
Old 08-05-2009, 01:11 AM   #5
Join Date: Aug 2009
Location: Mt Vernon, WA
Posts: 19
Rewards Points: 10

I agree - don't coat the posts. And don't wrap them because water will be more likely to find it's way in than out and you will end up with posts sitting in water all the time. Also agree that you need to get the right kind of pressure treated lumber. If you cut the posts before you cement them make sure you put the end that you didn't cut into the cement. The pressure treat doesn't always make it to the center of the wood so when you cut it you will expose the center part that is not as well treated.

Pressure treated lumber these days is pretty good. If you get the right type for the job it should last a very long time. I wouldn't worry too much about trying to make it last longer. You will probably cause more harm than you will help.

You can also get heavy post bases that pour into concrete and hold the posts with through bolts. If there is ever a problem you can take the post out and put a new one in.
elarreau is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bonding Ground in Conduit jamiedolan Electrical 5 01-26-2010 10:14 PM
home grounding problem smoke-wagon Electrical 7 06-25-2009 03:07 PM
Live ground wire in dryer Retired sailor Electrical 10 05-04-2009 03:26 PM
Sub Panel Grounding Question. RobertS Electrical 63 02-27-2008 01:50 PM
Installation of pergola posts HDelahay Landscaping & Lawn Care 13 10-11-2006 06:46 AM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1