Maximun span

Redoverfarm · January 30, 2008, 10:48:35 PM

Does anyone care to take a guess on the maximun span for 2"x6"T&G over 4X8 timbers?

Ernest T. Bass · January 30, 2008, 11:17:35 PM

48''? That's what we did. I wouldn't go more...

January 31, 2008, 12:21:10 AM

Quote from: Redoverfarm on January 30, 2008, 10:48:35 PM

Does anyone care to take a guess on the maximun span for 2"x6"T&G over 4X8 timbers?

No

Max span is not my thing

Bad idea IMO.

John_M · January 31, 2008, 08:07:56 AM

I used 4 x 12 (true dimensions) timbers in my cabin and they were at 48" on center. We used 2 x 8 T&G that was actually about 1 3/4" thick. Seems very solid to me!

It depends on how far your 4x8 beams are spanning as well. Mine was spanning 18 feet. (Plus I used a 4 x 12, you are using a 4 x 8 )

Good luck!

ScottA · January 31, 2008, 10:28:08 AM

Depends bow much weight you want it to hold and how many supports the boards are going to span. Best results will be if the boards span atleast 3 supports. For a floor I'd say 4' is a safe bet.

January 31, 2008, 11:33:41 AM

Oehler's engineer rated it around 250# psf for holding 2 feet of dirt and a foot of water on the roof of the underground cabin at 3'10" span or about 4' centers. Should hold people fine on 4' spacing IMO.

peternap · February 01, 2008, 11:57:23 AM

On the "I rekon it'll hold" charts, you'll be fine. I'd cut it in half on the "Damn Sturdy" chart!

John Raabe · February 01, 2008, 12:36:34 PM

If you are loading a 2x T&G deck for a loft load you can get close to 6' o/c according to old span charts from the 70's. I don't go much over 4' with materials you can get today.

If you are using this for a roof deck then it depends on the dead and live loads of the roof. A loft (for comparison) has a 30 lbs PSF live load and 10 lbs dead load. Main living floors are 40 lbs on the live load.

Redoverfarm · February 01, 2008, 01:11:08 PM

Thanks John. This will be a loft floor. One direction 51" the other is 46". Just trying to figure out which is the most benefical option to go around a fireplace in the middle of a room on three sides. The main loft rooms (excluding the fireplace surround) are only 36" span. These are 90 degree rooms off each other(16'X14' & 16'X18') so at one point I will have to change directions of the flooring run at the fireplace surround.

February 02, 2008, 10:51:19 PM

One house I did many years ago had 2x6 T&G hemlock decking on the 2nd floor. We needed it to span something like 5-1/2' if I remember right. It was a full upstairs with 2 bedrooms. With just the decking installed there was a bit too much of a bounce. We put down 5/8" plywood as carpet underlayment and everything firmed up nicely and there were no complaints.

That's maybe more than I would go today.

(Do we all get more conservative as we age?)

PEG688 · February 02, 2008, 11:13:47 PM

Quote from: John Raabe on February 02, 2008, 10:51:19 PM

#1: many years ago

#2: (Do we all get more conservative as we age?)

#1: I'd say that's the key thing , the lumber we have to use today is no where as good for the same size / or /and grade ! Older pre 1990 2x6 T&G , and other stock was better lumber.

I've watched it go down hill over the years.

#2: As far as "conservative" maybe it's just smarter