I need to buy some galvanized sheetmetal, for the purpose of building
a generator enclosure. The generator is 4x3x5 ft in size and is on a
wooden platform. So my plan was to make a frame from 1 inch angle, and
then bolt (not weld) sheetmatal to the frame. I want to use screws
instead of welding sheetmetal because I want every panel to be
That said, what sort of sheetmetal would be the most common one, I
want to know a bit before I call steel suppliers.
On May 25, 2:33 am, Ignoramus24299 <ignoramus24...@NOSPAM.
I want to use screws
If I were building the enclosure, I would use some OSB ( oriented
strand board ) under the sheet metal to cut down on the noise
transmission. It would also let you use thin sheet metal. I would
use pop rivets instead of screws. I would not expect to remove the
panel very often, but pop rivets can be easily removed by drilling
them out. Screws are likely to rust a bit and be hard to remove.
I am not sure what thickness of sheet metal is most common. Your
local HVAC shop will know that. But I expect somewhat thinner
material will be cheaper than the most common thickness.
On May 24, 9:33 pm, Ignoramus24299 <ignoramus24...@NOSPAM.
I like the steel roofing that HD and Lowes sell. They have both galvy
corrugated and painted flat with ribs, which looks better. The screws
to attach it have rubber washers that seal out water and allow thermal
expansion. I let pressure treated wood air dry before framing with it
and haven't had much trouble with corrosion.
Igor, I would be concerned about vibration exciting some fundamental frequency
of a steel sheet, causing it to make a real racket. Stiffeners, bent things,
extra mass, all would help.
The angle iron frame should be pretty rigid, but I've seen sheet metal surrounds
on cheap drill presses really take off vibrating ..
The use of two layers of _louvered_ sheet metal on the sides/ends [with the
louvers in opposite "/ \" directions] will both reduce vibration AND, while
providing adequate protected ventilation, reduce the sound level of the
running generator motor.
If desirable, sheet metal screws can be installed to add additional
For flat sheet you have your choice of thickness: 30 ga (.012" is just
too thin. 28ga (.014") is used for residential duct work, gets fairly
bouncy for panels over 24" minimum dimension. 26ga (.018") cuts nicely
with a snips but is getting harder to bend with hand tools. 24 ga
(.022") is sturdy stuff, I make small water trays from it. 22ga (.022")
is small tool box and trays for steel parts. for your application I'd be
looking at 24ga or 26 ga range with 28ga (a bit thin) and 22 ga (heavier
than you need) as options.
Flat galvanized sheet usually comes in 4'x10' pieces. My local has a
nice on-line calculator, their prices are for new, prime, quantity 1,
cash and carry.
26 ga $40
24 ga $45
22 ga $55
That works out to around $1 to $ 1.35 per square foot
The other choice is the ribbed steel panels sold at the home stores.
These are usually 29ga painted galvanized steel with 5 ribs. The steel
is a higher carbon than the flat sheets, has a fair higher tensile
strength. They come in 38" wide panels (36" coverage), 8',10',12' stock
lengths (special order any length up to 40') Usual price at a pole barn
supplier (NOT Home Despot!) is around $50 per hundred square feet.($.50
per square foot) They also have all sorts of 'J' edges, gaskets, trim,
etc to make a super nice job. Not to mention LOTS of nice colors.
I buy 'cover sheets' of this material to cover my wood piles: When they
make a shipment, the top and bottom sheets are some sort of seconds
(blah paint color, etc). They keep the cover sheets, sell them out in a
bargain area for $.50 a running foot ($.17 per square foot).
For outdoor use I'd recommend the pole barn sheet metal screws: hex
head, galvanized, painted to match the color, self drilling tip (it has
a nifty drill bit end!), and a rubber gasket under the head. Chuck up a
hex driver in the drill bit, insert screw, press hard. Goes right
through the sheet and anchors in the heavier stock below.
Someone mentioned using treated lumber for the frame. Not a good idea!!
The new treated lumber is extremely corrosive to steel, goes right
through the galvanized panels in a few years with regular humidity. If
it gets wet it can rust out in a year or less.
If it was me, I'd head for your local Menards store, check out the pole
barn display for ideas on how to make it look nice and keep it waterproof.
I don't know if looks are any part of this project, but I would
use metal building sheets and have a cap made to match that lipped
over the tops of the sheets, Metal building screws with washers
are readily available. The sheets can remove easily, though I
think I would rig it where it hinged back or picked up and off.
Keep the whole world singing . . . .
My dad bought a prefab galvanised water heater enclosure from some chain
hardware store. It has some louvers, but needs more for compressor duty, he
just removes the door when in use. It has no back wall, so it just attaches
to the building.
Defender of Freedom, Advocate of Liberty
I forgot to mention that I spray the corrugated panels with LPS3
first. Maybe that's why the ACQ treated wood doesn't corrode them.
Without it rust spots appear in a year or two. The galvanized screws
don't last long where the wood is damp so I punched washers out of an
old inner tube and used stainless and ceramic-coated bugle-head
decking screws. The stainless ones are soft enough that removing and
reinstalling them a few times strips the head, even the square-drive
Just buy a suitably sized cheap pre-fab garden shed and then focus your
efforts at gluing some acoustical panels into the interior for sound
control. The end result will likely look better, be done faster and be
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.