Deck Framing – all pressure treated or
MikeFinley
| Posted in Construction Techniques on
When it comes to deck framing do you use all pressure treated lumber for the framing or save money by only using it where needed, such as posts and exposed framing?
Since pressure treated wood out here is Douglas Fir with copper in it, why not save money and just use untreated Douglas Fir when possible?
If you are building a Redwood deck, you just use Redwood for the decking and railings and stuff that you see, and you use pressure treated lumber else where, so why not take it one more step and just use pressure treated where needed and result to untreated where it isn’t?
Edited 6/16/2004 8:58 pm ET by MikeFinley
Replies
Just what parts of this deck do you think need not be either treated or rot resistant?
If you're building it for yourself, and have no intentions of selling in the near future, I guess you can do what you want, even more so if you like taking risks. That way you'll have no one to blame but yourself when you have to start replacing the framing, and doing so requires disassembling the deck from the top down.
Cheap insurance. I build for others, so the price is included. When I built my own two decks, you bet your sweet pippy all framing, exposed or not, was PT SYP. And as they say down under, no worries, mate.
all this does the beg the question though...
which would last longer?
a guy building a deck with the new PT using reg nails and hangers, not knowing he has to use in the least z-max hangers and double hot dipped,
or
a guy building a deck using non-pt framming and reg nails and hangers?
does standard framing last longer then then the fasteners being eaten buy the new PT?
Man, just when I thought I had a fairly decent handle on the whole ISSUE, you gotta throw a monkey wrench in it. I know, build one of each, wait a few years and see which falls down first, then submit a report to good old Virginia State college of technical BS, and get famous overnight.
On a related note, I had to replace some deck joists a while back on a 8 year old deck, in CT, along the shore. SYP, not treated. Had started to rot on top of the joists due to the trapped moisture under the decking. So, I don't know. I finished a free-standing deck a few weeks back, and used SS deck screws, SS hangers, even SS hanger nails. SS screws everywhere. The clients wanted a maintenance-free deck with no worries. I gave them the best I could come up with. I guess only time will tell with all the questions...
I never met a tool I didn't like!
If you go with the non-PT, it depends a lot on the wood species and the climate. In Boulder, a deck that's carefully detailed, made of some modestly rot resistant wood, and gets some sun and regular maintance might last indefinitely. I just tore down a wood fence in my back yard that my neighbor tells me was 25 years old. The posts showed no degradation above grade, and most of the damage to the pickets was splits rather than rot. This was with no maintenance in the last 14 years and probably none before that, either.
I've seen two photographs of a downed tree in Colorado or Utah taken 100 years apart with no visible difference over that time span.
Cag - I would consider those to be any wood that won't come into contact with continuous moisture, such as wood in contact with the ground.
The treatment in PT wood is there to prevent rot from moisture. If the wood is left untreated with out any UV protection the sun here in the west will still crack, cup and split it.
Uncle Dunc - that is what I mean. Here in the west we really don't deal with molding or mildew like they do in the south east, northwest or north east. Our biggest concerns is wood drying out from the sun punishing it. I suspect that if I take 2 pieces of 4 x 4 x 8, one being PT and the other just Doug-fir and bury one end of each 1 foot into the ground. Then every two years I put another coat of UV stain on the doug-fir but leave the PT alone, eventually, if I compare the parts of each board that were exposed to the sun, the PT will be in rough shape structurally not sound, the Doug-fir would be in pretty good shape, however, digging up the buried ends, the PT would look good but the Doug-Fir would show signs of deterioration.
If you agree with that, then my original question here makes sense. If you disagree then my original question here doesn't.
Please correct my understanding if I'm incorrect
- the treatment on pressure treated wood is there to stop water from damaging the wood and to stop insects from damaging the wood.
- The treatment does nothing to increase the structural integrity of the wood, meaning you can't span any greater distances with a pressure treated doug-fir 2x10 then a non-treated doug-fir 2x10.
- The treatment does nothing to protect the wood from drying out or the effects of the UV rays of the sun.
the treatment on pressure treated wood is there to stop water from damaging the wood...
technically this is incorrect - the treatment is to stop microbial activity from damaging the wood - - I agree with your other points - "there's enough for everyone"
We built a porch on the west, with the joists hangered into the house on one side, and cantilevered past 6x10s on the other. The joists were pt, but for the 6x10s we doused them in Jasco. Don't know what the cost comparison is, though -- I think the Jasco is kinda pricey, but it might end up being cheaper. As for moisture in S. Cal. -- never seen any.