When did builders start using OSB for floor joists?

[SMS]

We looked at some houses today and since some in the development are not complete I walked in and looked at the construction quality.

I thought that floor joists were normally 2x6es or 2 x 8s, and was amazed to see that they were using a piece of OSB sandwiched between what looked like two 2x3s.

. You can see that this "joist" is inserted into Simpson joist hangers and it looks rather absurd to me.

You can't see it in that picture, but the sub-floor above the joists is screwed down to the 2x3s, but about 3/4 of the screws missed the 2x3 and went into nothing. It looked like they used liquid nails as well.

BTW, they are asking around $700K for these houses, which are right next to a noisy freeway.

[Ed Pawlowski]

Been around about 40 years.

Aside from missed screws, it is good construction. Straighter, stronger and cheaper than solid wood.

The use of liquid nails for the sub-floor helps prevent squeaks in a few years. Adhesives are rather strong.

Engineered wood I-beams were first introduced in the late 1960's and were used mainly for high-end home construction. However, today up to half the homes built in the United States now use engineered wood I-beams. Engineered wood I-beams are considered an excellent alternative to sawn lumber for floor joists due to their strength and overall lower installation costs.

[clare]

The "engineered Joists" work pretty well - and reduce the requirement for old growth timber - but missing the joists with the screws??? I'd run the other way. Sounds like a cheapskate shoddy builder passing off substandard workmanship at a high quality price.

[DD_BobK]

TJ-I's "Wooden I-beams" from Truss Joist.

Visit their website and take a look at all the "engineered" wood products. LVL, LSL, etc

In many (if not most) cases, engineered wood products are stronger, stiffer, straighter and drier than sawn lumber. Plus engineered wood conserves timber resources & allows the use of a wider range of species. (Driving factors in the development & use of OSB)

For rectangular sections (and members in general), member strength & stiffness are roughly proportional to wood density. Engineered wood products typically have more wood per cubic inch than natural wood.

I recently purchased an engineered 4 x 10 x 8 (actually 3-1/2 x 9-1/2 x 8') ... only $36 including tax It was WAY stiffer, stronger & drier than a similarly sized piece of sawn lumber. Plus I didn't have to deal with the nearly 3/8" of cross grain shrinkage that a green sawn 4 x 10 would have experienced.

Any extra cost was easily offset by performance improvements

Don't let the poor assembly workmanship taint your opinion of the materials.

cheers Bob

[harry]

Been common in Europe for years. Called engineered timber over here.

Lots of different components are made.

[Tim Watts]

On Sunday 17 February 2013 05:28 SMS wrote in alt.home.repair:

Didn't we do this a couple of months back

[George]

Do you also thing say a typical truss bridge as used for a road or railway is absurd?

[krw]

If you didn't live in such a hell hole, you wouldn't need to spend $700K for a piece of shit.

[recyclebinned]

I seriously doubt that they would stand-up well to getting wet as they are bound to do sooner or later if there is a leak somewhere some day, and labor to repair them isn?t relatively cheap here in the U.S. like it is in Europe.

[Ed Pawlowski]

There is risk and reward with every decision and every choice we make. Personally, I cannot think of a single instance in my life where they would have been wet enough to be damaged. I'm sure somewhere at some time they were. But it is not enough to make me think not to use them.

[Jim Elbrecht]

-snip-

Since those beams have been around [in the US] for 40 years, I think they've proven they hold up 'well enough'.

As for OSB-- I had a 3/4" pice covering a sump hole in my basement for

5-6 years. Now backing, framing, or protection from moisture. An 18" square hole covered with a 30" square chunk of OSB. I stepped in the middle of it regularly. When I finally got around to covering the floor and making a proper cover, that piece kicked around in the garage for years as I whittled it down for various small pieces.

OSB does a lot better than it looks like it ought to do.

Jim

[George]

I imagine that if the was ever on an commercial aircraft they would be rather upset to learn that a great deal of modern aircraft structures are bonded together with adhesives.

[krw]

As long as it doesn't get soggy it's fine. For decking I'd spend the extra for plywood. There's too much chance of water on floors. OSB doesn't hold nails well, either, so it's iffy for sheathing. There doesn't seem to be much downside to the beams. They seem to be coated with a waterproofing that should repel water that may come in contact with them (leaks, and such).

[DD_BobK]

Years ago... nearly 20, I did some work for a grumpy old structural engineer.

He hated OSB, he thought OSB was junk. He paid me to build and test some cripple walls.

We used full dimension old timber for framing and a number of sheathing materials. We used plywood on some specimens & OSB on others. We "over drove" the sheathing nails, we left the specimens outside & "watered them" everyday for weeks.

Much to his dismay... the OSB sheathed cripple walls (watered or unwatered, over driven or flush driven nails) all performed just fine.

We came away with a new respect to OSB.

TImber structures are designed & built to keep the materials dry, they do get wet at times but even sawn lumber has its limits.

OSB is good product, you can use it without concern.

I built a "temporary" shed out of OSB. I never painted it. It weathered about 8 years in SoCal...not a huge amount of rain (~15 inches pre year on average but a couple years with 20"+)

The surface of the OSB suffered a bit & generated some roughness but no delimitation & no loss of strength.

cheers Bob

[DD_BobK]

[clare]

What is sold as OSB today IS significantly better than the old "Aspenite" "Chipboard" crap. There is more resin in it - and a better grade as far as water resistance is concerned.

[recyclebinned]

s

When I see and smell genuine lumber I KNOW that what?s in it is pure Mother Nature. With OSB you can?t tell if and or how much of what is in it.

[HerHusband]

I used 1-1/4" T&G OSB flooring for our house (Don't recall the brand now). It's strong and doesn't have voids like plywood does. They also put some kind of coating on the sheets (wax?) that repels water nicely. Ours was exposed to rain for 3-4 months during construction. The water would bead up on top and we would just sweep it off each morning.

I'm sure long term water exposure would cause rot, but you would get that with regular plywood also.

I used CDX plywood for our roof sheathing because it's slightly stronger than OSB, and because it's lighter and was easier to carry up to the roof.

I also used CDX plywood for our wall sheathing, because I wanted a rough sawn face for simulated board and batten (even though we decided not to install the battens). I didn't care for the look of the textured OSB plywood.

Otherwise, I usually use OSB and CDX interchangeably. OSB is usually cheaper, so I tend to use it where appearance isn't an issue.

Anthony Watson Mountain Software

[krw]

So have I. In my own houses. It sucks.

If you get the nails into the framing, it's fine. Otherwise it sucks.

[krw]

OSB or particle board? I've seen some nice T&G engineered subflooring (decided to use 3/4" ply, though). It's a *long* way from the crap they use for sheathing.

Sure, I just worry about the bathroom. I've had ply disintegrate due to a very slow unseen leak. Termite barf will be worse.