A Quonset hut is a long, curved metal building that originated in World War II as a temporary troop shelter. Because its sides and roof are all one piece, it is much cheaper and easier to erect than a traditional building. Today some of the original huts still survive, and there are also companies producing modern variations that can be used for anything from garages to homes. While the design has many advantages, one of its disadvantages is that the huts often do not come with adequate insulation. The easiest way to insulate a Quonset hut is with spray foam.
Determine what you need the insulation for. If you are planning on living in the hut, it should be insulated as fully as any legal house in your area. If you just need it for storage or a shop you can get away with less.
Measure the size of the area to be sprayed. Measure the length of the floor, then the height of the walls. You an do this by getting on a ladder and running a string or tape measure from the ceiling, down the wall to the floor.
Order spray foam canisters either from a local shop or online. There are many different options for spray foam; some are better insulators, some are cheaper, some are more environmentally friendly, etc. Find the one that is right for you, and make sure you order a little extra.
Move everything out of the hut. Spray foam dries quick, so make sure there is nothing in the room for it to get on.
Put on your safety gear (including long pants, shirt and hat) and bring the canisters of foam into the room. Check the temperature strip on the bottles to make sure they are the proper temperature. If they are too cold or warm, put them in a warmer or cooler area for awhile and check again.
Attach the hose coming from the gun that is labeled "A" to the tank that is labeled "A". Attach the "B" hose to the "B" tank. Your spray foam kit may have come with petroleum jelly to lubricate the hose/tank connection, spread this on the connections before screwing in clockwise. Tighten the connections with the wrench.
Lubricate the end of the gun, where the mixing nozzle will attach. The mixing nozzle should then be screwed or locked into place.
Test the foam. Slowly unscrew the canister nozzles to make sure there are no leaks. Test a little foam in a garbage can or old cardboard box. Refer to the instructions that came with your foam kit to make sure it is coming out as the right color and drying in the proper amount of time.
Start spraying the walls evenly. Make sure you cover the entire surface area. Hold the gun about 18 to 24 inches away from the surface. Refer to your foam kit instructions to know how thick your particular foam kit should be sprayed.
Once you've finished, go around and check for any missed spots, especially the cracks between the floor and the walls.