Al and Robins 20x30 1 1/2 near Lake Eufaula, OK

Started by ajbremer, May 09, 2011, 04:01:01 AM

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Yes, everything is pressure treated and every fastener has been galv. and 16 sinkers.
Click here to see our 20x30 and here to see our 14x24.


Monday Night - September 19th, 2011

Found out today that I'll be getting 4"x4"x3/8 angle-iron that will run under all girders. I'll screw it to position it and then weld it.

I wonder if I can find a chart, calculation, or specification that would tell me how much weight this angle-iron can take in a given span.
Click here to see our 20x30 and here to see our 14x24.


From the AISC manual, which has span and load tables for channels and I beams, for shapes like this they give the section properties and then you work from there.
9.8 lbs/ft
r= 1.23"
Steel is not my strong suit, I believe you would use 29 x 106 psi for E
The formulas would be in publication DA6 under the publications tab at you would probably use formula 1, simple beam uniformly loaded, unless you have other loads.


Wednesday Morning - September 21st, 2011 Oklahoma, USA

I carried, dragged, and positioned a lot of heavy metal around yesterday that was delivered to me. This stuff is so heavy that I almost couldn't pick up one end of it and drag it.

I have 8 pieces of 20 foot long angle-iron that'll be positioned under my doubled 2x12 girders all the way around and down the middle, screwed, and then welded, the screws will hold them up till I weld them. This angle-iron is even thicker than the ones I used as posts. The 20 foot long sections are 4"x4"x13/32 (.406 thick)

Half of them are primed and half are not. I will spray Permatex Rubberized Undercoating on them and keep an eye on them.

Yesterday I also checked and toe-nailed each floor joist to the middle girder to get the joist ready for bridging.

Click here to see our 20x30 and here to see our 14x24.


AL that looks pretty good get you a jack and some blocks to push it up aginst your 2x and it will help hold it in place since it looks like you also are working alone. [cool]


Just because something has been done and has not failed, doesn't mean it is good design.


I'm glad you took the suggestions and the concerns of the others to heart

paint and seal before bolting on- then just grind where the welds will be


Thursday Night - September 22nd, 2011 Oklahoma, USA

Got 2 sections (1 thirty foot side) of angle-iron on today. Moving and lifting this iron in place has been the heaviest stuff I've done so far.

Each section of angle-iron is 20 feet long and it's 4x4x.406 thick and I have 8 sections to put up (now only 6 more). I had to be pretty creative to get it up by myself...strong too. I would lift one end up into 'near' position and then as I wrestled with it I would clamp it as close to the underside of the 2x12's as I could. Then I would go to the other end and lift it into position and try to clamp it while holding it up too. Once I got both ends clamped. I used a jack and chain to lift it up into position. I also put some tension, not a lot but enough to make good contact under the 2x12's. Then I clamped the down angle to the post and screwed TEK metal to metal screws in. Once I get them all up, the welder will come over and weld'em all.

I made sure that I would jack up the angle-iron near each post position so that it was in tension when I screwed in the screws. I can probably get up a section in less than an hour, now that I have a system down. Here's the pics:

Click here to see our 20x30 and here to see our 14x24.


Looks stout thats some thick angle. Like the chain and jack trick will have to try that , funny how working alone helps you come up with new ways to do things.


Glad you listened about the angle, i was begining to worry about you.

Good score.on the rv. Im looking at tye exact for $2500 or a 78 model for $2k. So i cwn get started on my cabin.

I drive hwy 69 two to four times a week. If you need an extra person give me a shout.


Friday Evening - September 23rd, 2011 Oklahoma, USA

Ok, I put up a full 20 foot section of that angle-iron after work today. It was heavier and took a little longer than I thought but I got it up and screwed in. Thank God for clamps and a jack!

Here's a pic of a full 20 foot section going in:

(Pic coming soon)

Click here to see our 20x30 and here to see our 14x24.


Sunday Morning - September 25th, 2011 Oklahoma, USA

Ok, all angle-iron has been installed underneath of every rim-joist/girder. Also, I had it all welded yesterday! It has been welded at every joint, every place where angle-iron meets a post and where angle-iron meets angle-iron.

Now, onto the bridging and sub-floor.

Here's a pic of the welder:

Click here to see our 20x30 and here to see our 14x24.


Be sure to paint the welds good, you no longer have any galvanizing at those points.

I wonder if the rubber undercosting would work on pressure treated wood post foundations? Hmm, ideas


West Tennessee


Al, I think your doing good and I love reading about your project.  Post more updates and pictures when you can. 


9-28-2011 Wednesday Morning, Oklahoma, USA

Thanks for the encouragement muldoon, I need it.

I have started the middle bridging, here's a pic:

I know I've mentioned this before but I 'was' planning on triangulating the 2x's that I'll be laying down as a sub-floor. I have other builders telling me that since I'm laying 2x's down instead of the usual thinner stuff, that I'd have no problem not triangulating the boards but just laying them down perpendicular to the joists. That way there'll be less waist and cutting of angles. Their saying that it'll be strong with no problems. Is that ok?

I plan on finishing the middle bridging and getting right to the cross bridging on the weekend. I'm excited about walking on top of my house!
Click here to see our 20x30 and here to see our 14x24.


Quote from: ajbremer on September 28, 2011, 06:13:25 AM
They're saying that it'll be strong with no problems. Is that ok?

No, or rather, NO!
Don_P has said it before and I have said it before, and I'll repeat myself one more time; Triangulate!!

Triangle shapes are strong. Boards laid at a 45 degree angle across the joists form triangle when nailed down. Lots of racking resistance there. Boards laid across the joists at a 90 degree angle form rectangles when nailed down. Not as strong; in fact not strong at all as far as racking across the deck.

It's the same reason we have suggested diagonal bracing at the posts and joists.  Don_P even drew the concept on a photo to illustrate.


If you don't believe that take some scrap 2x4 or 2x6 pieces two to three feet long. make a triangle and make a square or a rectangle. Secure each corner connection with 2 nails. Stand them up and push laterally on a top corner. What happens?  Then try nailing a scrap of OSB across the suare/rectangle shape. What happens then?

I would not trust any advice from a "builder" who says that boards of any size laid perpendicular across the joists was "good enough" or as strong as if laid at 45 degrees.

I'm not usually so blunt, but there it is. Triangles! Diagonals! 45 degrees!

Just because something has been done and has not failed, doesn't mean it is good design.


And if you do lay the 2x down at a 45 degree angle it makes the job easier if you leave the 2x ends square and overhanging a tad. Then when it's all done snap a chalk line and cut off the overhanging with a circular saw. makes for a nicer more even edge.

Structural floor sheathing, properly nailed and glued would make a floor unit that is even stronger though I'll wager.
Just because something has been done and has not failed, doesn't mean it is good design.


If you are using 2x material and what looks like 24" spacing perpendicular to the joist it should be plenty strong enough for any application you are going to use it for.  Running sheathing diagonally does create a better diaphragm and is stronger in some ways but weaker in others.  You are spanning a 40% greater distance with the wood c^2=a^2+b^2.  
If the joists are over 24" spacing, diagonally running sheathing is against code.  Although the chart surprisingly jumps from 24" to 48", because a 30" span run at a right angle would be around 42" span, which is less than the 48" allowed when running it perpendicular.
There may be even other engineering principles that come into play which make it weaker diagonally that I don't know about.

Proper nailing is a must when using lumber as sheathing.

IIRC from the various pictures and design's, John's plans call for 2x material perpendicular to joist.


Where the IRC states 1" and thicker flooring may be laid perpendicular to the joists the full sentence reads...

"Subflooring may be omitted when joist spacing does not exceed 16 inches (406 mm) and a 1-inch (25.4 mm) nominal tongue-and-groove wood strip flooring is applied perpendicular to the joists."  The bold type is mine for emphasis.

I stand by my statement that 2x12 material such as what AJ has, assuming it is just plain old lumber, not T&G, should be laid across the joists at a 45 degree angle.  We want that 20x30 foot rectangular main floor diaphram to be able to withstand forces that may try to distort it, bend it into a parallelogram, as best as possible. Hence the diagonal placement. Structural 4x8 foot panels are a little different as when they are laid across the joists in a perpendicular manner, the sheathing sheets turn the entire floor into a box beam laid on its side, rather than standing upright.

Someplace here there is a reference to a drawing that illustrates relative racking strengths of a wall sheathed with a variety of materials; wood strips perpendicular to studs, diagonally across studs and compared to various sheathing sheet goods. The same principles of strength apply to the floor unit as do the walls.

Just because something has been done and has not failed, doesn't mean it is good design.


Don is right. Sheathing is strongest but if you use 2 by's run them diagonally. Definitely.


Monday Morning - 10-03-2011 Oklahoma, USA

I've researched Advantech subflooring, my local Lowe's has it for $23.46 a sheet. It looks like it will withstand the weather while I try to get my walls and roof on asap. I'm going to call them today and ask them a few questions.

I have one more row of cross-bridging to do and then the floor. Here's a pic:

Click here to see our 20x30 and here to see our 14x24.


Looking Good!!! Your floor looks stout!
I wish we were this far along. We are still putting up beams, But they are going faster than the piers did.


The thing i.have wondered how the 4x8 sheeting will line up with the joists with them overlapped like that. That means one row of joists is on one side of the 16" mark and the other row is on the opposit side of it


We do this pretty often. Run the sheathing on the layout from the starting side. At the switch you scab a short piece of 2x4 alongside of the joist on the breaks to support the edges of the sheets and then shift the sheets 1-1/2" on the rows from then on so they are back on the "new" layout.