• WTB / WTS / WTT ADS
    All Advertisements, including Want to Buy, Want to Sell, Want to Trade, Belong in the MARKETPLACE ONLY. Any new threads posted offering an item for sale, looking to trade or buy an item which are posted outside of Marketplace will be deleted without notice or warning. Existing threads will be moved to marketplace.
  • Marketplace Feedback Ratings
    The Marketplace feedback ratings system is now back. You can now leave feedback for your Buy / Sell / Trade transactions. Instructions on how to leave feedback ratings can be found HERE

Carpentry / framing question - truss style

gunplumber

Arrogant Bastard
Gold Contributor
FALaholic #
96
Joined
Jul 21, 2000
Posts
28,327
Location
Surprise, AZ
Feedback: 353 / 0 / 0
I'm building a 14x14 hay barn/tac shed for the new property. I built the 12x12 one at my current property 20 years ago, after significant research. Probably way over-engineered. But it's held up very well. But I now forget why I did the trusses the way I did.

I currently have a 2x4 vertical running at the apex "ridge beam". The plans I'm looking at now call for no ridge beam and just OSB gussets. This seems a lot simpler as I can make a jig and just assemble the trusses on the ground. No king post on one of the plans, but it is on another - simple enough to add. Is there any strength consideration in the ridge beam style versus the gusset (or nail plate) style? Is a king post needed on a shed? Snow weight is not an issue in southern AZ.

4-12 slope. I chose this because it is (I understand) the most shallow slope for use with standard shingles, and if I went more shallow, I'd need to use roll shingles which I hate. May use corrugated steel, haven't decided yet.

Basically, I'm going to duplicate this, just a little larger. 200 sq ft is the max size not requiring government intervention (permits) and 14x14 = 196 sq ft.

Going to build two of them - the hay barn will be on a wood floor on concrete slab, like this one. The tool shed will be red-headed directly on the slab.
barn-60.jpg
 
Last edited:

alphadog58

Well-known member
FALaholic #
9405
Joined
Feb 14, 2003
Posts
5,439
Location
SE CT
Feedback: 5 / 0 / 0
Hopefully whoever generated the plans for the shed did the calculations and sized all the components of the trusses to handle the loads imposed on them. I would say follow the plans and you're good. A ridge beam, unless it has been specifically designed to be a structural load carrying beam, is just a nailer to attach the tops of the rafters to.
Yeah, most roof shingles are certified by the manufacturer to be good to a 3-12 pitch, 4-12 pitch is a better choice.
Larry
 

yellowhand

Well-known member
Silver Contributor
FALaholic #
67949
Joined
Nov 26, 2012
Posts
29,667
Location
Sierra Vista AZ
Feedback: 244 / 0 / 0
Unless its a complicated roof design, using a ridge beam,,,,pretty old school.

Trusses,,,and use the metal clips between sheet goods on a 2 ft center, you're good to go.

Ya got no snow loads, just wind loading, so use Simpson strong ties on all connection points.

Storm here last night, 74 mph wind gust,,,,you get them too.
 

Invictus77

1C16:13
Staff member
Bronze Contributor
FALaholic #
74205
Joined
Jun 13, 2014
Posts
13,518
Location
Western, KY
Feedback: 244 / 0 / 0
When I built an addition on our old house, I copied the design and materials of the professional made trusses that were used in my shop, but the new ones were to be a bit shorter. I built the first one in my pole barn, inside out of the rain and sun. When done, I outlined around it with a magic marker on the shop floor. I then built four more duplicates using the marks on the floor as the pattern. Worked for me.
 

gunplumber

Arrogant Bastard
Gold Contributor
FALaholic #
96
Joined
Jul 21, 2000
Posts
28,327
Location
Surprise, AZ
Feedback: 353 / 0 / 0
Clicked on for ideas. I ain't no carpenter. Trusses hardest part. We have a local company that makes just that. Reasonable price.
I do have a related suggestion . Why not use a metal roof and collect rainwater in a tote for stock.
Having a 140 gal/min 2nd agricultural well on 2" standpipes and a 56' water table, I'm not too worried about rain water. For the 10 days a year it rains - Like right now. It was a deciding factor on this property, which needed a lot of work. But two wells, and 20 acres make it worth while.

. I built the first one in my pole barn, inside out of the rain and sun. When done, I outlined around it with a magic marker on the shop floor. I then built four more duplicates using the marks on the floor as the pattern. Worked for me.
That's my plan. Get one right, then screw some 2x4 scrap pieces to the deck to outline it. Then cut the next 17 to fit in the same jig. It's the bird mouth and seat cuts that are new to me. but once I get the first one right, I can just trace it.

 

Invictus77

1C16:13
Staff member
Bronze Contributor
FALaholic #
74205
Joined
Jun 13, 2014
Posts
13,518
Location
Western, KY
Feedback: 244 / 0 / 0
Having a 140 gal/min 2nd agricultural well on 2" standpipes and a 56' water table, I'm not too worried about rain water. For the 10 days a year it rains - Like right now. It was a deciding factor on this property, which needed a lot of work. But two wells, and 20 acres make it worth while.



That's my plan. Get one right, then screw some 2x4 scrap pieces to the deck to outline it. Then cut the next 17 to fit in the same jig. It's the bird mouth and seat cuts that are new to me. but once I get the first one right, I can just trace it.

Also, mark them so you know which side was UP first when you used it to make the pattern and install them all facing the same direction. Even if the first one used as a pattern turned out slightly off kilter some way, if they all face the same way, they will all align correctly. Flip one the opposite direction and you would have a wave along the roof somewhere.
 

yovinny

Well-known member
Platinum Contributor
FALaholic #
7679
Joined
Oct 14, 2002
Posts
8,527
Location
Eastern PA
Feedback: 102 / 0 / 0
I dont like trusses without a king post...but at only 12' span, I guess its ok for an open shed and if your not putting any other load on the span..
 

jdowney

Well-known member
FALaholic #
51306
Joined
Jan 13, 2010
Posts
294
Location
New Mexico
Feedback: 18 / 0 / 0
This small in a non-snow load area you don't need to over build, just rafters from a supported ridge beam would be fine, I did a 16x16 that way several years ago, simple 2x6 rafter roof.

Trusses are a bit easier though, when it comes to the carpentry. No need for birdsmouth cuts and stuff, just get them up there and roll them, nail off and add some hurricane ties due to crazy monsoon winds. A basic W truss made of 2x4's with plywood plates nailed at the joints will do fine. I glue the plates myself, but I don't think its strictly necessary.
 

gunplumber

Arrogant Bastard
Gold Contributor
FALaholic #
96
Joined
Jul 21, 2000
Posts
28,327
Location
Surprise, AZ
Feedback: 353 / 0 / 0
Ok, another question. The tool shed will be affixed directly to an old slab with a little bit of patching for cosmetics. Heavy stuff needs to roll in, so no threshold. slab has a slight slope on all sides on the edges, so I don't anticipate too much of a water issue. But I assume I need to use pressure treated lumber in contact with the concrete. Ok, that's 4 14' pieces, I can probably go through the entire stack and find 4 that are straight. I dunno what the problem is, but local inventory of PT is anything but straight.

On the hay barn, my plan is to have a floor made of 1/2" subfloor, supported by 2x4s. On the newly poured slab. The perimeter will have holes bored in it for sub-floor ventilation, with screen to prevent critters from making it home. (see image in first post).

Is there some way I can "treat" regular KD Douglas Fir lumber to make it more like PT? Copper infused paint?

Reason is, Lowes has some pretty good straight 14' boards but their PT sucks! And If I need 14 or more of them, it's going to be a nightmare to find. I suppose I can use shorter ones and tie them together, but I dunno.

I'm thinking something like this without the beams, since it's on a slab.

Reminder - arid desert environment. Summer monsoons, but stuff dries fast in 100+F temps. Nothing is going to be sitting in water for extended periods. I just want to use the straighter untreated lumber if that's not a foolish plan.

shed-floor-joists.jpg
 

juanni

TROLL
FALaholic #
2439
Joined
Jan 29, 2001
Posts
26,944
Location
up a creek in MT
Feedback: 7 / 0 / 0
Original 'trusses' with a ridge beam.
Do they have a bottom chord or are they really just roof joists, spanning from the ridge beam to top plate?
If so, that is why you need a ridge beam.

If they are really trusses, they should be preassembled on the ground or elsewhere.
Not in your case, but if this was a large roof diaphragm blocking and edge nailing would be required at all panel edges and at the ridge with ridge blocking.



.............juanni
 

juanni

TROLL
FALaholic #
2439
Joined
Jan 29, 2001
Posts
26,944
Location
up a creek in MT
Feedback: 7 / 0 / 0
Pressure treated lumber is injected with the treatment under high pressure, that is what all those incision cuts are from.
You can't duplicate that by brushing or soaking.

AZ is notorious for termites, got both the dry wood type and wet wood type.
If the wettys smell wet wood they will make a mud tunnel from the ground, over concrete, dry wood and anything else to get to it.

PT lumber is usually low grade and sopping wet which is why is warps.



..............juanni
 

FIANNAFAL

Well-known member
FALaholic #
9035
Joined
Jan 23, 2003
Posts
1,732
Location
Mesquite Tx
Feedback: 0 / 0 / 0
Just because they are straight in the store does not mean. They will not dry further and warp.
Had to deal with a lot of returns when working at local hardware store.
Best find a dry place and finish the process.

Congrats on wells but gravity never runs out of gas or electric power.
 

Hermanthegerman

Well-known member
FALaholic #
87830
Joined
Mar 21, 2022
Posts
258
Location
North Carolina
Feedback: 0 / 0 / 0
Reason is, Lowes has some pretty good straight 14' boards but their PT sucks!
I experienced the same problem
Warped PT lumber @ Lowe’s
I found a small local lumber yard
They had some Kiln dried PT lumber (stamped KD - 19 )
Cost a little more but the 16 footers were straight, not full of knots & pretty dry ( KD 19 = 19% moisture content according to dude at lumber yard)
Don’t know about your area but maybe worth a look-see
 

jdowney

Well-known member
FALaholic #
51306
Joined
Jan 13, 2010
Posts
294
Location
New Mexico
Feedback: 18 / 0 / 0
For your hay barn, your best bet is to pre-treat under the slab for termites. Easy if the slab is not yet poured, less easy but not bad if it is - I remember buying the chemicals and renting a pressure injector tool at a pest control store in Tucson maybe 25 years ago. When you don't need documentation of treatment, you can DIY it.

Even in AZ dry rot is a concern as well for SPF lumber in contact with a slab or footing, so you need to use PT sleepers or pads to set the floor on. Given how they are neutering PT chemistry in the interest of non-toxicity to mammals, it is a good practice to put tar paper under the PT too. If you drilled holes for injection of termite death, you can plug them with the anchors for the PT if you plan ahead a bit. Otherwise a good flashing grade caulk will do it (not painter's caulk, you want something from the roofing isle).

That KD-19 sounds like good stuff too. There's got to be a smaller supplier who can order that or carries it somewhere around the Phoenix metro area. I've gotten some great lumber from small yards that actually give a shit about supplying quality goods.
 

alphadog58

Well-known member
FALaholic #
9405
Joined
Feb 14, 2003
Posts
5,439
Location
SE CT
Feedback: 5 / 0 / 0
Onliest wood species that has a porous enough grain structure to take pressure treating is southern yellow pine. SYP is also a more warp prone species than Douglas fir, which is your commonest species for framing lumber.
KD 19 will be more stable. Framing lumber can have as much as 28% moisture content.
Larry
 

FUUN063

Well-known member
FALaholic #
35576
Joined
Apr 16, 2008
Posts
7,353
Location
Converse, Indiana
Feedback: 508 / 0 / 0
Build a truss system. I usually go minimum 5/12 pitch. No ridge board needed on this type of system, just short boards connecting them plumb and square. Build one and that's your pattern. If you use screws to assemble the first one, ok it, then disassemble it for the pattern of each of the rest of the boards that way you don't even have to take time to measure the other components, just trace each end. Easier and faster. Time is money. Now, for when you lay the boards on the slab, make sure you use that blue foam material (insect/moisture barrier) that comes on a roll the same width as regular boards (imagine that). Roll it out directly where the boards will contact concrete or concrete block foundation. This is why they make it. Code here won't let you skip this part, js. I would also seal the concrete prior to building on it so moisture (not your friend) won't weep up through from the ground. Good luck.

Leland
 
Top