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4x4 Pressure Treated Question

Posted by columbusguy1 (My Page) on
Mon, Aug 27, 12 at 21:30

Background: The big storm at the end of June took out my 100 year old tree (it was leaning on the house--only needed to replace 7 shingles!). It also took off most of the remaining roofing on half of my 1908 garage.

Plan was to repair the roof, but turns out it would be better to tear down the most damaged half, and reframe one wall to give something half the size--I don't need an 18x22 garage, once all the junk was cleared out--so, I would have half that size garage, and the other half of the pad used for parking (a university area, so game days mean no street parking for residents).

Now the fun started: garage half gone, code inspector happened by--and said we couldn't use the other half since it was badly damaged by termites in addition to occasional leaks--not to mention one wall having been knocked off the foundation before I moved in. So, garage is entirely gone, leaving nice empty pad, and no place to store garden tools or lawn mower!

After days/weeks of investigation, I thought a kit might be the answer--a simple, 8x12 garden shed with 8 foot sidewalls, a double door on the alley side, a single door on the house side...one small barn sash would be nice, right? Let's just say, looking at all local companies in Columbus, Ohio and the big-box stores...I don't want to spend nearly 2k to get a basic box which would need additional framing to make it not blow away.

Seeing a kit I could live with, I read the instruction sheet online, and the comments. Even I know that 2x3 lumber is crap, and this thing was made of it--one comment was to upgrade to 2x4 framing...and I thought--then I'm stuck with about half a kit which is junk.

Inspiration! Price materials to see if it would be cheaper! Boy was it--if I used 2x4 framing, it would cost about $400 since I had the shingles and paint already. Simple task to frame walls, but LOTS of cutting, nailing and lifting!

Second inspiration! Why not use pt 4x4s for the frame--no major hassles cutting 2x4s. Notch a few spots and it's all set to fit together--if I want to go crazy and use dowels--otherwise big ass nails or screws.

Here's the problem: since the shed will be 8x12 feet, and eight feet high walls, I need to know what distance I can span with a 4x4--I've looked at spanning tables and most don't mention 4x4s that I can find. With sheathing being 4x8, I will need to inset a 2x4 in the long sides to but the sheathing together...will one be enough to break the 12' length into a 4' and an 8' section...or should I inset two on 4' centers? Top and bottom plates are 4x4s as are the corner posts.

Similar question goes for the rafters--but I'm pretty sure I will be spacing the 4x4s there on 4' centers just for strength and nailing purposes


Follow-Up Postings:

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RE: 4x4 Pressure Treated Question

I would suggest amish sheds (and garage) builders in your area.


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RE: 4x4 Pressure Treated Question

Welcome to the 'if you touch it, it must meet the present code' problem.


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RE: 4x4 Pressure Treated Question

Homebound, as I mentioned, I cannot afford 2-3k for a shed.

Brickeyee, ain't it the truth?!

Still, can't anyone tell me how far I can span with a 4x4? Will I need 1 support or 2 on the 12' walls?


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RE: 4x4 Pressure Treated Question

I would highly suggest just framing it 'normally' using 2x4s. You may not like cutting, nailing and lifting, but in order to build a shed, you'll have to do those things.

It will probably also be cheaper since two 2x4s are cheaper than one 4x4.


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RE: 4x4 Pressure Treated Question

And why does your title say "Pressure Treated"? You are planning on putting shingles and siding on, right? You don't need pressure treated studs and rafters. That will save a lot of money too.


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RE: 4x4 Pressure Treated Question

The joist, roof and ceiling span tables in the Code I work under, the Ontario Building Code, do not cover 4x4s used in those situations.


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RE: 4x4 Pressure Treated Question

I am planning on using pressure treated at the very least for the bottom, as that will be in contact with the concrete slab--I've heard of putting a 'foam gasket' thing under it in those situations, is there such a thing?

And, pt is almost the same cost as untreated for the bottom pieces, so why not be safe? Also, I'm thinking 4x4s because it will make stronger joints especially at the corners--toe-nailing 2xs together to make a sill seems too flimsy if there should be strong winds.

I will spec the price for using the 2xs, but I'm betting it will wind up about the same, since there are more of them required than for 4xs.


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RE: 4x4 Pressure Treated Question

I recommend that you buy plans for a shed or garage that you like and follow the plans exactly. Yes, it may be lots of cutting and nailing, but it's a tested plan designed by professionals.

Bigger is not necessarily better.


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RE: 4x4 Pressure Treated Question

The shed kit I liked, as I said originally, was made with 2x3 stock, and I read through the entire thing with illustrations of all the parts--half of the wood was junk which would warp easily if it didn't already come that way--hence, my wanting to use heavier timbers.

I am not some yahoo, I have done extensive reviewing of plan books from the period, and am not unfamiliar with how to design and plan projects. My plan will yield a shed just like I want, at less cost than any kit I've seen which wasn't resin or metal.


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RE: 4x4 Pressure Treated Question

Hi, CG! I'm certain that no one familiar with you thinks you're a yahoo, (although you did make me grin - haven't heard that term for ages!).

There's a difference between "a kit" & "plans", & you don't need to pay for plans - google "free shed plans", & be prepared! "Ask.com" has 15 links, w/pics, to different sources - including Popular Mechanics (love that one!).
They include a "parts list", & detailed instructions. Why do the heavy thinking, when you already have to do the heavy lifting/labor? Or.. You can alter their plans, to make it your own creation if you choose. Many styles, historic included, so you can easily find one to look right next to your amazing house. :-)


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RE: 4x4 Pressure Treated Question

What were you planning to use for the roof sheathing? No material I can think of short of stress-skin panels will tolerate rafters on 4' centers. And purlins put you back cost-wise at rafters.
Casey


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RE: 4x4 Pressure Treated Question

Was planning on osb for roof sheathing, topped with asphalt shingles--now that you mention it, I guess the rafters will need to be standard 24"o.c. Dang.

Hey KS! I'll have to check the links you mention--I was going to replicate the look of my old garage--without the lean, of course!


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RE: 4x4 Pressure Treated Question

I am not sure how far a 4x4 spans, however, I think you are very smart to use treated as your base against the concrete though. The cost of treated is negligible compared to not treated here, actually when I built my extra raised beds this year the treated was cheaper.

We just resided a garden shed last month that had a lot of rotting issues (it was built at the bottom of the hill in the yard). The bottom is where it takes the water damage. We used a pvc trim at the bottom which covers the connection between the wood frame and the concrete slab. We did similar on the house except on the house we actually routed the pvc to match the German lap siding, on the shed, we didn't get that detailed.


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RE: 4x4 Pressure Treated Question

I don't think the wall sheathing is designed to only be attached around the edges either and will probably warp pretty badly. That's why you'll need studs spaced at least 24"oc in the walls as well.

Using pressure treated for the base plates is necessary (as you knew) but the rest is totally unnecessary. Make sure you use galvanized nails when using PT lumber.

I'm thinking 4x4s because it will make stronger joints especially at the corners--toe-nailing 2xs together to make a sill seems too flimsy if there should be strong winds.
Flimsy? Most houses are built using 2x4s, so it will be plenty strong enough for a little shed. Plus, if you want to make something stronger, it is much more beneficial to use 2x6s than 4x4s.
And, if you don't like to toenail (even though there is nothing wrong with that) then build the walls laying on their sides so that you can nail up through the base plates and down through the top plate, and then tip the wall up into it's proper position and attach it to it's neighbours.


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RE: 4x4 Pressure Treated Question

Oops, I quoted the wrong site. You probably don't need plans, anyway.. I know I would, but I can't even build something w/Legos without the step-by-step instructions. (Just thinking about figuring out a parts list - ugh. Give me a printout to hand over to the guy in the blue apron, lol).

http://freebies.about.com/od/homegardenfreebies/tp/free-shed-plans.htm

You can practice on yours, before you come to KS to build mine. I'm liking the "colonial" one, now. Or cottage style, or...


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RE: 4x4 Pressure Treated Question

If you don't know why 4x4's are not included in span tables you need to find a competent designer/contractor to design and build the structure.


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RE: 4x4 Pressure Treated Question

4x4 often contain the pith of the tree, and are NOT as strong as a pair of 2x4s scabbed together.

Look at the end of most 4x4s and you will see the nice circle of the pith


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RE: 4x4 Pressure Treated Question

Brickeyee...that is a surprise, considering post and beam con structed houses are still around after 300 years! :)

I still like the idea of using 4x for the sills...my brother in law also suggestes 2x4s and raising pre-assembled walls from the ground.

Seems the guy who took down my garage, has walked off with my money for materials--four times now he has failed to show with them--always some new excuse. It would cost money to take him to court, but I hate to see him get away with it; I was surprised because he did so well taking down my tree!

OH! News on the city tree front: the city is going to grind down the stump--and I get a new tree in Spring, since planting season ended early last Spring, many people were moved to this Fall, so I have to wait. And--I get an elm tree, as I had asked for! Yay!


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RE: 4x4 Pressure Treated Question

".that is a surprise, considering post and beam con structed houses are still around after 300 years! :) "

They are not made from modern 4x4 dimension lumber.

Post and beam lumber does not normally contain pith.
it was purposely cut away.


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RE: 4x4 Pressure Treated Question

the foam gasket thing..
sill seal. blue foam gasket that goes
between 2x and concrete. more for air sealing
than anything else. but since you asked...
http://www.lowes.com/pd_13281-46086-108957_0__?productId=3363032&cm_mmc=PLA_BuildingSupplies-_-InsulationAccessories-_-gps-_-5-1/2" Sill Seal Roll &adtype=pla&cagpspn=pla

best of luck.


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RE: 4x4 Pressure Treated Question

You don't need the code to tell you how far a 4x4 will span but you do need to know the loading. But in general, the span of a shallow member is often determined by the deflection allowed under maximum design load.

Deflection resistance is determined by the Moment of Inertia of the cross section of the member. For a 4x4 I = 12.5 and for a 2x6 I = 20.8 and for a 2x8 I = 47.6 so it should be obvious that a 4x4 is a poor choice for structural framing.


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