# Lumber Grades/Quality **URL:** \ **Category:** Factual Questions\ **Created:** [May 27, 2016, 8:03pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849 "2016-05-27T20:03:05Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [May 27, 2016, 8:03pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/1 "2016-05-27T20:03:05Z")
I’m thinking of replacing my deck floor over the weekend, and am pricing (pressure treated) lumber. But I’m confused about the grades of lumber out there. Home Depot told me they only stock one grade. One local lumberyard told me they have two types, standard and “premium”. Another told me they only carry one type and it’s “premium”. So I asked the last guy what the meaning of these terms is. He claims that they are industry standard terms, and the types are #1, #2, and “premium” (and these vary in terms of how many knots and the like). Is this correct? Is one store selling “premium” lumber selling more or less the same thing as other stores selling things under the same name, or do I need to visit lumberyards in the area and try to compare them visually? ---
**Author:** ![Doctor\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/doctor_jackson/32/32_2.png) [@Doctor\_Jackson](https://boards.straightdope.com/u/Doctor_Jackson)\ **Post date:** [May 27, 2016, 8:17pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/2 "2016-05-27T20:17:08Z")
Lumber grading scales depend on the type of wood. Since you are talking about deck flooring, I’m going to guess you’ll be using 5/4 pressure treated pine. I have attached a link that explains the [grading scale for eastern white pine](http://durginandcrowell.com/eastern-white-pine-grades/). It really boils down to the number and type of knots allowable per board foot. For deck flooring a standard grade should be fine, unless you prefer the aesthetics of fewer knots. Also note that grades above “standard” are usually much more expensive. If you’ll be using something else, Google “\_\_\_\_\_\_\_\_\_ lumber grading”. And visual inspection is always a good idea! ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [May 27, 2016, 8:17pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/3 "2016-05-27T20:17:12Z")
From my experience Home Depot tends the sell the lowest grade lumber possible in order to keep prices down. For some projects it doesn’t matter that much, but for other projects I shop the higher end lumber stores in my area. I would be surprised to hear that Home Depot was selling low grade lumber as anything other and low grade. ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [May 27, 2016, 8:47pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/4 "2016-05-27T20:47:45Z")
> [@Doctor\_Jackson](#): > > For deck flooring a standard grade should be fine, unless you prefer the aesthetics of fewer knots. I had thought that knots make it more likely to disintegrate. Also, your link says that grading is also based on splits. > [@](#): > > Also note that grades above “standard” are usually much more expensive. Doesn’t seem that way to me. I’m in the market for 38 pieces in 12’ lengths. HD is charging $9.67 per for their grade (whatever it is) plus they charge $65 for delivery which works out to $11.38 per. The place offering “premium” is charging $11.57 with free delivery. (The place that had two grades is charging $8.89/$12.11 plus $25 for delivery.) ISTM that unless there’s virtually no difference between the grades, it makes sense to go with the $11.57 guy. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 27, 2016, 8:52pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/5 "2016-05-27T20:52:00Z")
Pressure treated deck flooring is pretty solid even with lower grades, but knots can degrade faster and provide an gateway for decay. I wouldn’t take a delivery of such lumber from the Home Despot (and even most lumberyards). You should go and pick out the boards yourself. They’ll just grab anything off the stack. They should have a cheap rental truck that you can use to bring them home. ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [May 27, 2016, 9:05pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/6 "2016-05-27T21:05:24Z")
I would deal with the lumber yard on this one. The guys at the lumber yard are going to be better trained and more likely to give a shit. The material, even if the same grade as Home Depot, is generally better due to things like higher turn over. The yard I deal with for decking and outdoor lumber has staff that know what material is acceptable and what to tos in the shorts bin. Ultimately you sre best off picking material yourself, but a good lumber yard is going to take returns on bad deck boards so ask about their policy. On a decking project I am going to sort through the material and set asside poor boards to either use for short sections, discard or return. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 27, 2016, 9:20pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/7 "2016-05-27T21:20:43Z")
First of all, why are using pressure treated lumber for your decking (what you call “flooring”)? Pressure treated will be used for posts, stringers or ledgers, sometimes joists. “Select” or #1 is used for structural elements like headers. You should be able to buy decking that is either cedar or redwood. If you want something a little special, try Ipe. It’s a Brazilian hardwood that is very rot resistant. And it looks beautiful. You pay for it, but it looks really nice. ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [May 27, 2016, 11:55pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/8 "2016-05-27T23:55:13Z")
> [@TriPolar](#): > > Pressure treated deck flooring is pretty solid even with lower grades, but knots can degrade faster and provide an gateway for decay. > > I wouldn’t take a delivery of such lumber from the Home Despot (and even most lumberyards). You should go and pick out the boards yourself. They’ll just grab anything off the stack. They should have a cheap rental truck that you can use to bring them home. You can also pull your order and hand it off to them for delivery. I’d never trust HD to pull an order for me. They have too much garbage to sort through to find anything decent. If your lookingat PT or ACQ I wouldn’t bother with premium, just pick out the boards yourself. ---
**Author:** ![newme](https://avatars.discourse-cdn.com/v4/letter/n/e0b2c6/32.png) [@newme](https://boards.straightdope.com/u/newme)\ **Post date:** [May 28, 2016, 12:49am UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/9 "2016-05-28T00:49:03Z")
> [@John\_Mace](#): > > First of all, why are using pressure treated lumber for your decking (what you call “flooring”)? Pressure treated will be used for posts, stringers or ledgers, sometimes joists. I don’t know where you live, but where I live, any untreated pine boards will disintegrate in a year or two if exposed to the elements. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 28, 2016, 1:31am UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/10 "2016-05-28T01:31:41Z")
> [@newme](#): > > I don’t know where you live, but where I live, any untreated pine boards will disintegrate in a year or two if exposed to the elements. He advised rot resistant cedar or redwood, not just pine. And painted pine will last a number of years. What do you think people were doing before Pressure Treated wood was available? ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [May 28, 2016, 4:09am UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/11 "2016-05-28T04:09:54Z")
Look out for Brown-colored Pressure Treated lumber. PT was the one type of lumber I’d buy from HD. There are specs (not much, but it does have to be Kiln Dried (which most of HD is NOT). But: For PT lumber: Green = Good for Structural Brown = for appearance only Do not put down brown PT and try to walk on it unless you have really good joists and lots of them. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [May 28, 2016, 4:19am UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/12 "2016-05-28T04:19:31Z")
Here’s a professional tip: Look at the end of the board, AVOID them that came from the center of the tree … and you’ll see the “bulls-eye” pattern of tree rings. They’ll twist and cup and warp and all manner of nasty things. You might have to pick through the unit to find enough for your needs. Just seems to me that the mills pick the absolute worserest boards for pressure treating. ---
**Author:** ![slash2k](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@slash2k](https://boards.straightdope.com/u/slash2k)\ **Post date:** [May 28, 2016, 5:36am UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/13 "2016-05-28T05:36:04Z")
> [@TriPolar](#): > > He advised rot resistant cedar or redwood, not just pine. And painted pine will last a number of years. What do you think people were doing before Pressure Treated wood was available? They were using old-growth redwood, mostly, but that is effectively unavailable now. (As the man at the lumberyard explained to me awhile back, “the good lumber doesn’t grow on trees anymore.”) Second-growth redwood does NOT have the same resistance to rot that the old stuff had, and in much of the country will still need to be protected (sealed, stained, painted, whatever), or it will rot–maybe a little bit slower than unprotected pine, but much faster than the tight-grained pure heartwood for which the old stands were justly famous. > [@](#): > > The heartwood from old-growth trees has high decay resistance. The heartwood from second-growth trees generally has low to moderate decay resistance. – [http://www.libertycedar.com/MainSite/Store1/Content/SiteContent/1/Home/redwoodsequoia.aspx](http://www.libertycedar.com/MainSite/Store1/Content/SiteContent/1/Home/redwoodsequoia.aspx) ---
**Author:** ![ASGuy](https://avatars.discourse-cdn.com/v4/letter/a/838e76/32.png) [@ASGuy](https://boards.straightdope.com/u/ASGuy)\ **Post date:** [May 28, 2016, 12:16pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/14 "2016-05-28T12:16:14Z")
I live in far northern California, Behind the Redwood Curtain as we commonly say. The Big Trees are all around us here, fortunately mostly protected now. In any case, I agree with **slash2k** that old growth redwood is gone and that second growth is less capable than old growth. On the other hand, we can still acquire old growth material as salvage from old houses and barns. Around here, no one wanting an exterior deck seriously considers using “new” redwood. It doesn’t perform well and won’t last without aggressive ongoing maintenance. Salvaged old growth is hideously expensive and inconsistent from an appearance perspective. Nope, modern decks up here use composite decking material. By way of full disclosure I do not have a deck and my few conversations with lumberyards in the area suggest that even the composite materials are not a panacea for long term deck survival. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 28, 2016, 12:27pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/15 "2016-05-28T12:27:13Z")
Redwood and cedar are expensive also. I rebuilt my parents deck around 1976, with old growth Redwood flooring. They were just 4/4 boards but plenty strong on 16" centers. The original deck would have been over 10 years old, and it was ordinary pine framing lumber. Paint had kept it that long. The flooring was still stable but the joists were rotting away. These days I’d recommend Cedar if you want natural wood, but remember only heartwood, and preferably White Cedar which has started to come down in price some after supplies were short for a while. But there’s nothing wrong with PT or composites, especially when they have a serious cost advantage. Guys like us are looking at the wood, everybody else is looking at the decorative flooring patterns and fancy rail work, and most owners are marveling at their decks made out of plastic just like their Legoland houses. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 28, 2016, 2:31pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/16 "2016-05-28T14:31:59Z")
Please, guys. “Decking”, not “flooring”. 😉 I’ve just never heard of anyone using PT boards for decking. Do you live in some unusual environment? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 28, 2016, 2:41pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/17 "2016-05-28T14:41:04Z")
> [@John\_Mace](#): > > Please, guys. “Decking”, not “flooring”. 😉 > > I’ve just never heard of anyone using PT boards for decking. Do you live in some unusual environment? It used to be very common, less so now because of the abundance of composite materials. I’d say 90% of the decks built here in the northeast were PT before this century. Now it’s a much, much smaller percentage, but still can be cost effective. ETA: 90% of the decks still standing. The ones that used pine are long gone. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [May 28, 2016, 2:45pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/18 "2016-05-28T14:45:11Z")
> [@John\_Mace](#): > > Please, guys. “Decking”, not “flooring”. 😉 > > I’ve just never heard of anyone using PT boards for decking. Do you live in some unusual environment? Building codes generally require PT (or equivalent) for any location within 18" of grade. That might be local to the rain forested areas where everything stays dripping wet ten months a year. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 28, 2016, 2:53pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/19 "2016-05-28T14:53:05Z")
Do you mean 18 _degrees_ of grade? We have crazy steep lots in some places in CA, and I’ve still never seen a PT deck. Maybe I’m just not noticing… ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 28, 2016, 2:57pm UTC](https://boards.straightdope.com/t/lumber-grades-quality/755849/20 "2016-05-28T14:57:09Z")
> [@watchwolf49](#): > > Building codes generally require PT (or equivalent) for any location within 18" of grade. That might be local to the rain forested areas where everything stays dripping wet ten months a year. Never heard of that around here, but I never checked either. The inspectors only seem to care about the posts being properly set below the frost line. They never come back after that. New home construction may get more notice. Then again, what is the equivalent? If it’s composites and rot resistance woods that pretty much leaves pine-y woods and you’d be crazy to use those now. [Next page](https://boards.straightdope.com/t/lumber-grades-quality/755849.md?page=2)