11

The contractor I hired is using these PT Douglas Fir joists. They look old. he says they are structurally sound just discolored. I took a screwdriver and poked the joist and it did not sink in at all. very hard. he said he is going to cut off the split ends. I am concerned as to why the wood looks burnt.

Can someone look at the images and let me know if they look ok?

enter image description here

enter image description here

enter image description here

FreeMan
  • 37,897
  • 15
  • 71
  • 155
Cecilia
  • 111
  • 1
  • 3
  • 1
    If the contractor used "new" pressure treated lumber being sold today, you could expect considerable shrinkage as the lumber dried to normal water-content level. If the screwdriver test tells you it's hard wood (not spongy, etc), the lumber is fine. I'd a lot rather have old fully cured wood to build with, regardless of discoloration, than new wet pressure treated lumber. New takes 6 months to a year to dry and shrinks quite a bit. A pressure washer can always take care of the discoloration. – David C. Rankin May 05 '22 at 01:28
  • This is not burned, just what wood looks like after it has dried (often in the sun) for a while. – TylerH May 05 '22 at 13:45
  • I assume the asker used it as a figure of speech. Burnt wood would look charcoal black (because it has turned into charcoal) :) – MiG May 05 '22 at 16:12

4 Answers4

22

I took a screwdriver and poked the joist and it did not sink in at all. very hard.

That's your key right there. There's nothing wrong with the wood, it just doesn't look very pretty.

If it were bright and blond and "new" looking, well, it wouldn't be pressure treated. Pressure treating will make the wood dark like that. Those look a little darker than what I'm used to seeing but they look just fine.

I'm sure your contractor will cut a 1/2" or so off the ends of most boards to square them up, and will probably cut enough off the ends to get rid of the bit of split that's formed (and is a natural occurrence when wood dries), but otherwise, you're just fine.

Far more important is that the boards are reasonably straight and not warped. It's possible your contractor might find a board or two that is too warped to use, and he should set these aside, but some amount of bow and twist is acceptable. Usually they get returned to the store for a refund if they're too far gone.

Once the wood has been outside for a year or so as part of the deck, it will begin to weather to a much lighter grey color.

FreeMan
  • 37,897
  • 15
  • 71
  • 155
  • 2
    I would also suggest that the newly cut ends are treated with preservative. – Peter bill May 04 '22 at 20:33
  • And warped/twisted boards are also useful if cut to smaller sizes to use for cross blocking or other shorter spans where the warping is mitigated. – TylerH May 05 '22 at 13:47
19

The other answers addressed the appearance of the wood with great accuracy so I'm not going to beat that dead horse.


Are you getting a good deal on the deck? These boards could have been purchased pre-covid for less than 25% of today's prices so if you were quoted for materials using current prices then the contractor is pocketing the difference. Heck, for all we know these boards were abandoned somewhere and the contractor took it upon themselves to "find" them.

However, labor prices have also skyrocketed so if material costs weren't disclosed upfront then the contractor could easily pad some numbers if you're asking for a cost breakdown retroactively.

If pressure-treated wood lasts about 40 years as a deck then these boards may have lived through 3, 5, or more of those years already. Is that something you're willing to pay full price for?


After having a second look at your question, the workmanship is a bit concerning.

enter image description here

Additional issues have been identified after I created the picture so here is the full list below containing my observations and those of the comments section:

  • Missing post-cap ties are a big concern for me
  • V-dip in the beam supporting the rim joist end of the deck
  • The beam in the middle of the deck appears to be just a 2x8 holding up an 4x4 and doesn't even span the entire width of the deck
  • I didn't see any tension ties to tie a couple of the joists into the house, through the ledger board

I highly advise getting this thing independently inspected.

MonkeyZeus
  • 15,488
  • 2
  • 21
  • 57
  • Looking closer (@1:1 zoom), "V-dip" on the left may be a "beveled" corner, cut at 45° - joists above keep being parallel. – Astrogator May 03 '22 at 15:34
  • 5
    @Astrogator I was hoping that OP would chime in just saying it's just an issue with a wide-angle photo but we really don't know unless another picture is provided. Also, the absence of post cap ties joining the posts to the rim joist is another big concern. I reall hope OP is getting this thing independently inspected. – MonkeyZeus May 03 '22 at 15:46
  • 1
    agreed the V-dip seems to be a corner. Looks like the left beam extends beyond the joists... maybe just incomplete on the corner? The center beam far end appears to be sitting on a nailed cleat. Hard to be definitive from the picture, but looks like some nails are missing in the joist hangers. This is not how I'd frame this as an amateur, and I'd be saying a hard no to any pro that framed my deck with such a random collection of columns, beams, and (lack of) ties. – Doug May 03 '22 at 16:22
  • The contractor probably _isn't_ pocketing the difference - he's probably using the money to replenish his stock. – Martin Bonner supports Monica May 03 '22 at 17:08
  • @MartinBonnersupportsMonica You have a lot of faith in the regularity in which this contractor does such projects that they actually maintain stock; especially given the observable craftsmanship. – MonkeyZeus May 03 '22 at 17:18
  • 2
    @MartinBonner Lots of contractors are not very good at the business side. They buy lumber to finish your job with the down payment from a new job. For those types, using old lumber at full price is a windfall. –  May 03 '22 at 21:06
  • 3
    I think your 20 year life estimate is way under. For pressure treated, up in the air where it will stay mostly dry, you're looking at decades longer. 75 years even. –  May 03 '22 at 21:12
  • I didn't see any tension ties to tie a couple of the joists into the house, through the ledger board. – SteveSh May 04 '22 at 01:18
  • @19565 Let's meet in the middle, 40 years per https://woodworkingclarity.com/how-long-does-pressure-treated-wood-last/ unless it is immaculately maintained. – MonkeyZeus May 04 '22 at 11:48
  • "I Pray This Is Temporary" -- good eye, but it's not. Given the length of the deck and given the joint running the length of the deck where the joists dead-end into the board and are then extended to the full width of the deck, there will need to be some type of load-bearing structure under that joint. From the photo, as you noted, it appears the contractor chose to support a portion of that joint, relying on the minimal length of the remaining span to be carried by the board used between the two joist sections. Work of equivalent quality to the V-dip spotted (also good eyes) – David C. Rankin May 05 '22 at 01:22
  • 1
    Hey, at least they put joist-hangers on the side connecting to the home. – David C. Rankin May 05 '22 at 01:23
  • 1
    @DavidC.Rankin "at least they put joist-hangers on the side connecting to the home" - I feel like there must be a pretty solid horror story to back up this comment =) – MonkeyZeus May 05 '22 at 12:57
  • Echoing a little bit what Astrogater mentioned, the V dip is possibly just an angle (though I think it's clearly nowhere near 45 degrees. Hard to tell at this perspective, though. Re: "*these boards may have lived through 3, 5, or more of those years already*" that's good and bad: Good: OP doesn't have to worry about shrinkage or warping from irregular drying with slightly aged wood (unless these were already KDAT, then it's moot of course), which can really wreck a deck, or at least its look, after installation. Bad: the contractor pocketing a massive pre-COVID price difference is a concern. – TylerH May 05 '22 at 13:51
  • @MartinBonnersupportsMonica the contractor pocketing the difference is just them taking more money. What they do with it (paycheck or re-invest into their business) is irrelevant. A project should have two costs: labor and materials. The customer should know what they're paying for. If the contractor wants to charge a premium to help cover future costs of materials, tools, whatever, that's fine if the customer is OK with it based on the level of quality they perceive the contractor to have in their work, but the customer needs to do their due diligence on the money, too. – TylerH May 05 '22 at 13:53
8

To answer your specific question, “are these okay?”, yes.

They may have been sitting outside for a while, but there aren’t going to be any structural issues. Once built, you won’t really be able to see much of them, so the aesthetic issue will go away as well.

Aloysius Defenestrate
  • 18,266
  • 1
  • 30
  • 52
3

That's just how aged Douglas fir looks like: it gets really dark after a while. But that's a good thing, the oxidized layer protects the inner structure.

I built a DIY table with Douglas fir 2 years ago:

fir wood table - before

After 2 complete years outside, it now looks like:

enter image description here

Granted, it doesn't look very good, but it's now protected and the structure will look just the same in 5 or 10 years.

The wood shrunk a bit, and sadly, there's now enough space for forks to fall down.

Which means it's better to use Douglas fir for building a structure once it's already weathered.

Eric Duminil
  • 487
  • 4
  • 9
  • Your table wasn't built of PT lumber in the first place, so the treating will contribute to the darkening. – FreeMan May 05 '22 at 11:37
  • 1
    On the plus side, the added space will help to reduce crud accumulation in between cracks on top of the support beams. Accumulated crud holds in moisture and speeds up the rot process. Looks great though! Here is a picnic table I built just 2 years ago https://i.stack.imgur.com/iWi03.jpg and today it definitely looks like your second picture. – MonkeyZeus May 05 '22 at 12:54
  • @MonkeyZeus: Wow, color me impressed. The picnic table looks *really* good, very stable and professional. Do you have more info about it? – Eric Duminil May 05 '22 at 13:13
  • @EricDuminil Sorry, in a meeting now but I'll be happy to provide more info/pictures when I get a chance! – MonkeyZeus May 05 '22 at 13:57