framing the camper interior
- Thread starter henrys103
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I've considered metal as well as I have worked with both metal and wood framing, but in general construction.
Metal framing is lighter than 2x4 framing, it may not be with 2x3 or 2x2s. Using metal studs really depends on your plans. Techniques differ from woodworking, you certainly don't bend anything anytime, you cut through it with a chop saw and allow the track (as a bottom plate) and studs as well as the top track (top plate) to be notched with clean fitting cut allowing "tabs" at 90 degree joints when appropriate and rivet those connections, otherwise you screw everything.
Running wiring and plumbing is much easier than wood, at least in a 2x4 or 2x6 wall. If your connections are properly installed and "tabbed" at the top and bottom I doubt you'll have any squeak.
The upside with metal, lighter (as mentioned) not rot and no cracking. Once you get use to working with metal a job can go much faster.
In this case, time won't be a big plus, a small run of walls, short bracing and probably the mixture of wood and metal you probably won't be saving time here. In fact, if we factor in the learning curve for a first timer your framing job may take twice as long.
If you use metal, I'd suggest you NOT use framing in this manner as an electrical ground for anything.
Metal can be stronger than wood, but the lateral strength comes from the covering of wall materials and the space between studs, the closer the better. If you were to go from an 16" centers to 12" centers it will be much stronger, but you probably just lost your weight advantage. Build time also increases. Strapping the studs with flat bar also helps as walls will be rather flimsy until all elements are attached. If you use an 1/4" or 3/8ths ply wall covering and blow foam in that should stiffen a wall substantially. (Using expandable foam, too much, could bend or bow studs if walls are attached, the 2x4 studs have very little lateral strength).
Another downside is attaching wall cabinets or interior furniture, the gauge used in studs (I forget the gauge) can hold expanding wing bolts (spring loaded type) if you put much weight on any screw size you'll have problems as the screws will work lose IMO.
Wall blocking is done with wood and it needs to be cut square exactly to length for a good fit, it's not rough in carpentry anymore. A Jack stud or short stud can be used between blocking vertically too. So you need to layout your cabinet and furniture placement carefully. Use wood for attaching such interior work.
Metal framing fits at a 90 degree angle intended to be used with plumb and level construction. That may present issues for a roof, you can't set studs or rafters with a twist to make an angle as the ends would be, say 15% off plumb to set a slanted roof to fit square to the roofing material, that would not be a secure joint. You could use wood shims as a fillet between the horizontal rafter and the roofing material, or if a bowed roof a wood bow on top of the metal.
Now, my stuff didn't go rolling down the road much less off road. Flex, depends on the design, metal stud framing won't follow wood construction. It won't stretch or shrink but it does twist easier than wood. I'd have diagonal strapping, top, bottom and sides, I'd have to see it to have an idea of where and how. You're twisting the frame in three directions. Hurricane straps can be use as well as some of the sheet plate hangers and joint materials used in building a wood deck, after a little fab work.
Electrical runs through plastic grommets in the studs, the metal is sharp and would cut through insulation in no time, so don't run lose wire through metal studs. I'd probably use electrical pvc pipe as conduit or conduit running with commercial standards. You can just use grommets, depends on the wiring. If you used conduit you're again defeating the weight advantage of using metal.
Poly or rubber hoses will have similar issues against a sharp edge, water, air, shower, I'd say use grommets at the very least for anything running through the studs.
I have assumed you're thinking of exterior and interior walls, if you are thinking of just using an exterior wall, about all the metal framing will do is to hold the wall pieces together or in position, you're wall joints will be most important, I'd also think it wouldn't last long over the road since metal studs really need both sides supported to reduce twisting and lateral movement, shear and wind loads are reduced.
Bolting something to the flange of a metal stud inside or out I'd suggest you use washers or better a heavier plate behind so the lock nuts would not pull through.
IMO, both metal and wood can be used. I think metal would be better for a lifting top where the walls are about 3' high. It would be lighter. I believe for a rock solid camper (I know there isn't one) you'd need to use a lot of blocking, under the top plate along the bottom plate and wall, windows and doors should probably be done in wood or wood frame and jam.
My overall suggestion is use box steel or aluminum for framing, not metal studs. A welded frame should last a few life times if well designed, protected, powder coated or painted if steel and covered. I know lots of guys use 2X4s to build furniture and campers, it's dead weight that's unnecessary, it's not really stronger in short pieces in such applications as 2x2 or 2x3s properly fastened and jointed. I'm also looking for every square inch of space in a camper, a 1/2" can make a difference in your water line bend or joint lasting or rubbing and breaking lose. The only thing I over build are decks, I use RR ties as posts and piers, 2x6 decking, other than that I use the smallest and lightest material to build with that is safe and appropriate, I'd rather have an overly braced 3" or 2" wall than a standard 4" frame. Design pays off.
Metal framing is lighter than 2x4 framing, it may not be with 2x3 or 2x2s. Using metal studs really depends on your plans. Techniques differ from woodworking, you certainly don't bend anything anytime, you cut through it with a chop saw and allow the track (as a bottom plate) and studs as well as the top track (top plate) to be notched with clean fitting cut allowing "tabs" at 90 degree joints when appropriate and rivet those connections, otherwise you screw everything.
Running wiring and plumbing is much easier than wood, at least in a 2x4 or 2x6 wall. If your connections are properly installed and "tabbed" at the top and bottom I doubt you'll have any squeak.
The upside with metal, lighter (as mentioned) not rot and no cracking. Once you get use to working with metal a job can go much faster.
In this case, time won't be a big plus, a small run of walls, short bracing and probably the mixture of wood and metal you probably won't be saving time here. In fact, if we factor in the learning curve for a first timer your framing job may take twice as long.
If you use metal, I'd suggest you NOT use framing in this manner as an electrical ground for anything.
Metal can be stronger than wood, but the lateral strength comes from the covering of wall materials and the space between studs, the closer the better. If you were to go from an 16" centers to 12" centers it will be much stronger, but you probably just lost your weight advantage. Build time also increases. Strapping the studs with flat bar also helps as walls will be rather flimsy until all elements are attached. If you use an 1/4" or 3/8ths ply wall covering and blow foam in that should stiffen a wall substantially. (Using expandable foam, too much, could bend or bow studs if walls are attached, the 2x4 studs have very little lateral strength).
Another downside is attaching wall cabinets or interior furniture, the gauge used in studs (I forget the gauge) can hold expanding wing bolts (spring loaded type) if you put much weight on any screw size you'll have problems as the screws will work lose IMO.
Wall blocking is done with wood and it needs to be cut square exactly to length for a good fit, it's not rough in carpentry anymore. A Jack stud or short stud can be used between blocking vertically too. So you need to layout your cabinet and furniture placement carefully. Use wood for attaching such interior work.
Metal framing fits at a 90 degree angle intended to be used with plumb and level construction. That may present issues for a roof, you can't set studs or rafters with a twist to make an angle as the ends would be, say 15% off plumb to set a slanted roof to fit square to the roofing material, that would not be a secure joint. You could use wood shims as a fillet between the horizontal rafter and the roofing material, or if a bowed roof a wood bow on top of the metal.
Now, my stuff didn't go rolling down the road much less off road. Flex, depends on the design, metal stud framing won't follow wood construction. It won't stretch or shrink but it does twist easier than wood. I'd have diagonal strapping, top, bottom and sides, I'd have to see it to have an idea of where and how. You're twisting the frame in three directions. Hurricane straps can be use as well as some of the sheet plate hangers and joint materials used in building a wood deck, after a little fab work.
Electrical runs through plastic grommets in the studs, the metal is sharp and would cut through insulation in no time, so don't run lose wire through metal studs. I'd probably use electrical pvc pipe as conduit or conduit running with commercial standards. You can just use grommets, depends on the wiring. If you used conduit you're again defeating the weight advantage of using metal.
Poly or rubber hoses will have similar issues against a sharp edge, water, air, shower, I'd say use grommets at the very least for anything running through the studs.
I have assumed you're thinking of exterior and interior walls, if you are thinking of just using an exterior wall, about all the metal framing will do is to hold the wall pieces together or in position, you're wall joints will be most important, I'd also think it wouldn't last long over the road since metal studs really need both sides supported to reduce twisting and lateral movement, shear and wind loads are reduced.
Bolting something to the flange of a metal stud inside or out I'd suggest you use washers or better a heavier plate behind so the lock nuts would not pull through.
IMO, both metal and wood can be used. I think metal would be better for a lifting top where the walls are about 3' high. It would be lighter. I believe for a rock solid camper (I know there isn't one) you'd need to use a lot of blocking, under the top plate along the bottom plate and wall, windows and doors should probably be done in wood or wood frame and jam.
My overall suggestion is use box steel or aluminum for framing, not metal studs. A welded frame should last a few life times if well designed, protected, powder coated or painted if steel and covered. I know lots of guys use 2X4s to build furniture and campers, it's dead weight that's unnecessary, it's not really stronger in short pieces in such applications as 2x2 or 2x3s properly fastened and jointed. I'm also looking for every square inch of space in a camper, a 1/2" can make a difference in your water line bend or joint lasting or rubbing and breaking lose. The only thing I over build are decks, I use RR ties as posts and piers, 2x6 decking, other than that I use the smallest and lightest material to build with that is safe and appropriate, I'd rather have an overly braced 3" or 2" wall than a standard 4" frame. Design pays off.
Last edited:
southpier
Expedition Leader
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You're right, good point. I was speaking to the Lowe's / Home depot stuff. In my area that is a special order $$ we have commercial steel suppliers as well, $$$. At that point I'd check on the cost of box stock. I like spray form but 2" sheets might be less expensive and easer to work with too.
Another point I missed above was the insulation properties of wood vs. steel, wood is much better, might be interesting to see a thermal image of metal studs attached to siding and the interior wall, I'd bet it would look like strips of cold or hot areas next to the insulated panels. The metal will conduct heat or the loss of heat much faster than wood, I'm sure someone here is better at physics than I am. Everything is a trade off.
My error above, I meant to say 16" centers, not 18", edited that. Lots of variables and ways to skin the cat, without a drawing it's difficult to suggest what might be best, although.....box steel or an aluminum build would probably win out every time for a camper, it usually boils down to the builder's welding skills, paying to have it built could get pricy real quick. Maybe the OP will find his post and give more information as to what he has in mind, size, budget, etc.