building a shed — key phrase TIGHT BUDGET
ldodge429
| Posted in Construction Techniques on
Good morning all —
In my “spare” time (2:00 am is always open :), I am building a 24 x 12 shed on a TIGHT budget. The 8′ walls are up and now I am working on getting a metal roof on it. Trusses, though easy and fast are out of budget so I need to build my own rafters / trusses. I would prefer a clear span but am open to ideas. The pitch is going to be about a 5/12 or 6/12 (have to measure the house pitch so I can match it), with a 1 foot overhang around entire building.
Any thoughts / suggestions would be greatly appreciated :). Ridge pole vs. ridge beam vs. home made trusses, etc. I live in central Tennessee so thank GOD — snow load is not a big issue. Oh and I am building this by myself so keep that in mind.
Thank you much
LDodge
Replies
Hope the span is the 12 foot one.
you can easily make trusses yourself.
once you figure out the layout, put one on the ground flat.
You should be able to make the bottom of one 12 foot long 2x4, and the sides (that rise to the peak) of 8 ft 2x4s. make a few shorter lengths of 2x4 for internal truss parts, shoot for a W.
use 1/2 inch plywood glued and screwed (or nailed) into the side of the 2x4 parts, and you will have a truss.
Lift each to the roof one end at a time, and hang them upside down. then turn one at a time up and secure with 2/4s used as purlins under the metal roof.
make sure you install cross- braces along the bottoms of the trusses, And across the first couple trusses on the vertical, and you should be good to go.
That's the best plan.
About $20 each in new lumber for each "truss".
Thank you Uncle Mike
You are correct -- the span is the 12 foot side. So I have another shed (8'x12') on our property (one of those that you get at Home Depot or Lowe's) that has 2x4 rafters that are attached at the peak with a piece of plywood on each side -- no ridge pole or beam; so why could I not copy something like that? Adding a beam would not be a difficult thing and from what I understand this would support the roof enough.
Again thank you much
LDodge
What you see at THD has been engineered to within an inch of falling down, iteratively removing bits & checking the structural sim to see if they can make it slightly cheaper.
How tight is "tight"?
Here's a commercial figure for the sake of comparison -
https://www.menards.com/main/building-materials/trusses-i-joists-engineered-lumber/roof-trusses/12-4-12-residential-common-truss/1875186/p-1444448745982.htm
Times 13 trusses for 24 feet of roof, plus twelve sheets of 3/4 Advantech is about $1050.
You can throw around homemade trusses with OSB gussets, but depending on your lumber I don't see a huge savings there.
He says he's on a tight budget and you tell him to spend $38 a sheet on 3/4" advantech?
One thing to keep in mind is that 12 ft is 50% longer than 8 ft. The roof load will increase in a similar way.
And with your shed being 24 ft long, you need to keep the tops of the side walls from bowing out from the weight of the roof.
You could get away with a home made triangle truss (plywood or OSB gussets at the connections)
But if you will be tempted to put stuff in the "attic", more structure might be a good idea.
You can also just use a ridge beam and cut the roof joists to match and sit on the walls. (framing cuts)
Still will need an element to keep the walls from bowing out, You can get away with either roof ties, or a few 12 footers spaced every few rafters.
Plan out exactly how you will place the framing and hold it in place while you install fasteners and the rest of the supporting structure.
the home made truss idea is a little more forgiving on cut precision. Lay it out on the floor and cut to match. Each truss ends up simple to lift into place. with a metal roof, you will want each side of the roof to be square and flat.
do you plan on framing under the metal roof, or OSB/plywood sheathing?
I have found on occasion that I could buy trusses very competitively compared to the cost of making them. Especially if you accurately figure what your fasteners and gusset materials cost. Stick framing your mileage may vary but I'd suggest actually pricing pre made trusses before assuming.
I have to agree on pricing a pre-made truss first. Someone set up to make them is likely to be a lot faster (and thus cheaper if you count your time) and more accurate, and might even deliver them for no charge. Plus, they already have the design.
I have made trusses for my own projects and it's no big deal, but it is time consuming with plywood gussets. If you do it that way, it helps a lot to have a floor or deck to use for assembly. You can screw down blocks to help position the pieces quickly and accurately. But get decent lumber. the twists and turns of bad sticks will drive you crazy.
I don't get the problem. Are you looking not to have ceiling joists? Then it makes sense. Then, as others have said, you should be able to find some internet source for site-building trusses. It's only a 12 ft. span with no real snow load. You could probably do a scissors truss easily.
Thank you all
I am pricing out trusses now :) Just curious though why is everyone steering away from rafters? They are easy enough to cut and very easy to handle / install?
2 x 4 are not rated for a 12 foot roof span, even with a 12 inch spacing.
And you wanted cheap,
If you want to use low cost 2x4 for the rafters, you would need a ridge beam sized for the roof load over 24 feet. (or a couple support posts in the middle of your shed, and you wanted free span) 2x6 will be ok, but a little more expensive.
When you go to an engineered truss, the structure helps you. (this is also true for a field-made truss, but you are guessing at the engineering)
most trusses will be specified for a 24 inch spacing.
Why not just go with 2x6 rafters and 2x4 ceiling joists? You could even move the 2x4s as much as 1/3 up the rafters if you wanted more headroom. And honestly, for a shed with no snow load, you could probably get away with 2x4 rafters. They're only spanning half of 12 feet. The worst they'll do is sag with time.
Span is 12 feet, unless the installed ridge board is a beam designed to carry the load.
For a shed, I agree you might get away with using 2x4 for the rafters, and no ridge beam, esp. with a metal roof. I would not get on such a roof, and would need to plan for access from a ladder.
Each rafter only spans 6 ft. The ceiling joists spans 12 ft. I'd want 2x6 rafters anyway, to leave a little meat above the bird's mouth to handle the overhang.
Listen to UncleMike42.
This will sound crazy, but it's true. Years ago I built a 12 x 16 greenhouse as cheaply as possible. I used three 2x4 trusses I built (yep, 8 feet on center), and infilled with 1x4 'rafters'. The ridge was a 16 foot 1x8, and I left a slot in the middle truss so it could drop in place. It was covered with 6 mil greenhouse grade poly, with a four year life.
Pretty cheap, maybe 200 bucks for materials. Here's the best part. It lasted for 8 years. In New Hampshire, with plenty of snow. I have one photo of it after a storm deposited 18 inches of snow on it overnight. It was designed with no eaves so the snow slid off readily as soon as sun warmed the inside, but if the snow was over a foot deep I pushed it off from inside with a broom poked against the plastic. It never collapsed, I took it down because the KD lumber finally got punky.
How could this work? It was far below any spec for a structure that size. I believe it was like the old airplanes built with wooden frame and covered with fabric and they needed to be as light as possible. Imagine the stresses on those in flight. The poly was tight as a drum in the winter when the cold shrunk it. But at the time I lived in a 19th century timber frame farmhouse with purlins that were literally small trees. tapering to as small as 4 inches in an 8 foot span ( on an 8/12 pitch). No one was knocking snow off of that building for 180 years, and they did get snow. The truth is that building codes are prescriptive, not absolute, and no one tests every possible configuration of materials and design. Building by committee you are bound to get only rules that everyone can agree to, even the most worried. If it's not risking life and limb it's fun to see what you can do.