Pressure-treated Wood For Deck Joists? - Building & Construction - DIY Chatroom Home Improvement Forum


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

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 04-13-2009, 01:11 PM   #1
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Question

pressure-treated wood for deck joists?


We've hired a contractor to replace our collapsed deck with a new Trex deck. I'm wondering whether we should be using pressure-treated wood for the joists and supports? Our contractor said that we did not need to use pressure-treated wood because it isn't in contact with the ground. (The support posts have concrete blocks to stand on.) Hopefully my contractor knows what he's talking about, and we don't need pressure-treated, but I was looking for some confirmation or advice.

Thanks,
Mark

Advertisement

beiley is offline   Reply With Quote
Old 04-13-2009, 01:33 PM   #2
Member
 
CrossWorks's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 163
Rewards Points: 150
Default

pressure-treated wood for deck joists?


About 22 years ago I built a deck for my soon to be Farther-in-Law. Last summer I replaced the decking "only" and the PT framing was still as solid as "Day 1". When a contractor says what yours said, I suspect two things:

#1. He didn't figure it in the price.
#2. Or the deck is fully under cover and out of the elements reach.

There have been a handful of decks and porches built prior to the "PT Lumber age" that I have taken down over the years, and the number one location for rot to occur is where the nail drives into the wood. It makes a perfect wick for water to get in and do it's damage. So I suspect your contractor may be one of two: Young and inexperienced, or middled aged and not so honest. Then again...who am I to judge.

Just be prepared that if you insist on PT (which imo should of been the first approach by the contarctor) then expect to pay more for the job. How much more??? It all depends on the pricing in your area. But just to give you an example; Here in Maine I pay these prices:
  • 1- 2 x 6 x 8' Spruce $4.43
  • 1- 2 x 6 x 8' PT Lumber $5.97
  • 1- 2 x 8 x 12' Spruce $7.68
  • 1- 2 x 8 x 12' PT Lumber $11.45
So now you have an idea that the difference should not be to bad.

Advertisement

__________________
A great personality will open many doors in life,
but it's your character that keeps them open!

www.crossworksme.com
"Where Every Nail Has a Purpose!"
CrossWorks is offline   Reply With Quote
Old 04-13-2009, 01:51 PM   #3
Registered User
 
Join Date: Mar 2009
Posts: 9,986
Rewards Points: 2,038
Default

pressure-treated wood for deck joists?


Where I live, all outdoor - open to the weather- structures have to be pressure treated. I would contact your local County Building Department for answers. Find out before it is too late. It depends on locality.

They do not "have concrete blocks to stand on." Here is their site:

http://www.coconino.az.gov/uploadedF...20Dwelling.pdf

Frost Line – Frost line Depth shall be thirty (30”) inches in Coconino County with the exception of Oak Creek/Sedona, Marble Canyon, and Greenhaven, where depth shall be twenty-four (24”) inches.
EXCEPTIONS – Detached accessory structures located in residential zones for private use, sized less than one thousand (1,000’) square feet, single story, and may have a foundation depth of eighteen (18”) inches into undisturbed soil. Be safe, GGBAR
Gary in WA is offline   Reply With Quote
Old 04-13-2009, 03:03 PM   #4
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

pressure-treated wood for deck joists?


Thanks for the info. The deck is not covered. It is in northern AZ, where a lot of snow falls. It sounds like it should be built with PT joists/posts. My contractor stated in their initial bid that the under pinnings would be built with "standard or better Doug Fir". Unfortunately, I used this bid to get reimbursed by my insurance company, so if the job price goes up now I guess I have to eat the difference...
beiley is offline   Reply With Quote
Old 04-13-2009, 03:06 PM   #5
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

pressure-treated wood for deck joists?


Water will collect under the edges of the decking & rot out the joists

PT is a must

I hope Trex has improved their product
Scuba_Dave is offline   Reply With Quote
Old 04-13-2009, 04:14 PM   #6
knewbie
 
curapa's Avatar
 
Join Date: Nov 2007
Location: Savannah Ga
Posts: 56
Rewards Points: 75
Default

pressure-treated wood for deck joists?


Quote:
Originally Posted by beiley View Post
We've hired a contractor to replace our collapsed deck with a new Trex deck. I'm wondering whether we should be using pressure-treated wood for the joists and supports? Our contractor said that we did not need to use pressure-treated wood because it isn't in contact with the ground. (The support posts have concrete blocks to stand on.) Hopefully my contractor knows what he's talking about, and we don't need pressure-treated, but I was looking for some confirmation or advice.

Thanks,
Mark

You need to stop your "contractor" right away and find a new one that knows what he's doing. The cost difference between PT and untreated fir is not that much. If you do decide to keep the same "contractor" on the job I would make him eat the cost, it is after all, his fault.
__________________
ParkerFenceandDeck.com
curapa is offline   Reply With Quote
Old 04-13-2009, 05:30 PM   #7
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

pressure-treated wood for deck joists?


GBAR makes a good point
If this is attached to the house then it needs footing below the frost line

How many estimates did you get before going with this one?
Why did the last one collapse?
Scuba_Dave is offline   Reply With Quote
Old 04-13-2009, 05:42 PM   #8
Newbie
 
Join Date: Mar 2009
Location: WI
Posts: 6
Rewards Points: 10
Default

pressure-treated wood for deck joists?


Curapa is right.
Check the building codes. PT is probably required. If so, then your contractor is building in violation of code and should be liable for most, if not all, cost difference to PT. He shouldn't be in business if he's going to quote un-treated when PT is required.

Good luck.
Caddyshack is offline   Reply With Quote
Old 04-13-2009, 06:14 PM   #9
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

pressure-treated wood for deck joists?


Wow, thanks for all the advice. Now I'm rather nervous. I already paid him 1/3 the cost of the job. He is in the middle of removing the current deck that collapsed. This contractor built my neighbor's house, and was recommended by my neighbor. He was very happy with him. I trust the recommendation, as I know my neighbor quite well. This contractor is from the area, so I would think he should know the regulations. There hasn't been any talk of a building permit. Do I need one to replace an existing deck, with one the same size?

The current deck collapsed because it didn't have enough supports in the middle. There was a section that was only supported at the edge, and at where it connects to the house. It broke off where it was connected to the house under a heavy snow load. The contractor quoted that he would provide supports at 8' centers on the replaced deck. These support posts are currently on concrete slabs. I'm not sure of the right terminology, but they look like they are in the ground, and not just sitting on top of the ground. They look like they are about 16" on a side. I have no idea how far into the ground they are.

I will call the Coconino county building office to ask about PT.

Thanks.
beiley is offline   Reply With Quote
Old 04-13-2009, 07:02 PM   #10
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

pressure-treated wood for deck joists?


If building without PT & it is called for by code they can make you take it apart & fix it. Might not happen, but not really worth the problem to go with reg wood VS PT. If a building permit is required & one is not pulled they can fine you

Knowing the regulations & following them are 2 different things

Posts need to be secured to the metal brackets
Then the metal brackets need to be secured into the concrete
If the posts do not go below the frost line then freezing & thawing will stress the connection to the house. Possibly causing failure

Scuba_Dave is offline   Reply With Quote
Old 04-13-2009, 07:29 PM   #11
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

pressure-treated wood for deck joists?


I called the county, and the rules here are that anything 6" or more above grade are not required to be PT.
beiley is offline   Reply With Quote
Old 04-13-2009, 09:39 PM   #12
knewbie
 
curapa's Avatar
 
Join Date: Nov 2007
Location: Savannah Ga
Posts: 56
Rewards Points: 75
Default

pressure-treated wood for deck joists?


Quote:
Originally Posted by beiley View Post
I called the county, and the rules here are that anything 6" or more above grade are not required to be PT.
Required or not, PT is needed for exterior applications. I would call him on it, you do not want to be paying someone else for the same project in a few years.

Check out these sites by professional deck contractors, all framing is PT.

http://www.builtbymac.com/

http://www.winchesterdecks.ca/

http://www.decksetc.ca/

http://www.alscustomdecks.com/
__________________
ParkerFenceandDeck.com
curapa is offline   Reply With Quote
Old 04-13-2009, 09:45 PM   #13
Newbie
 
Join Date: Apr 2009
Location: AZ
Posts: 9
Rewards Points: 10
Default

pressure-treated wood for deck joists?


Thanks for all the help and advice. I am planning on using PT. I will pay for the difference though, as his initial quote didn't include PT, and was within building codes in my area. I am spending a lot on the deck and Trex, so I want the joists/supports to last the same long time.
beiley is offline   Reply With Quote
Old 04-13-2009, 10:27 PM   #14
Member
 
CrossWorks's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 163
Rewards Points: 150
Default

pressure-treated wood for deck joists?


Not sure if you've every heard of CorrectDeck decking, but the product is made here in maine and I designed and built this deck a couple years ago using the CX Decking which has intergrated deck fasteners. Is guaranteed to not have any mold or they'll replace it.

Check it out: Yarmouth Deck


And the entire frame was PT. Oh...and here's the site on the decking
__________________
A great personality will open many doors in life,
but it's your character that keeps them open!

www.crossworksme.com
"Where Every Nail Has a Purpose!"
CrossWorks is offline   Reply With Quote
Old 04-14-2009, 01:37 AM   #15
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Rewards Points: 250
Default

pressure-treated wood for deck joists?


Let's not confuse pressure treated with treated lumber, there is a difference. Your contractor is right "pressure" treated lumber is not needed because it is not in contact with the ground, however at the very least "treated" lumber should be used.

Advertisement

Mop in Hand is offline   Reply With Quote
Reply


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
Pressure Treated Wood-Direct Ground Contact Randell Tarin Building & Construction 14 10-14-2011 10:52 PM
Bottom plates are not pressure treated Richo Building & Construction 10 03-16-2009 06:48 PM
garage sill is not pressure treated danz Building & Construction 14 02-21-2009 09:25 PM
ceramic ove pressure treated Gery Flooring 3 04-06-2008 12:33 PM
Don't use these nails on treated wood? scarrell Carpentry 3 04-01-2006 11:41 AM




Top of Page | View New Posts