Adhesives are becoming more and more common on construction jobs, and the tool you need to work with them is a caulking gun.
Caulking guns come in a range of sizes from smaller 10-ounce models good for home improvement, to battery powered sausage guns for pros who work with adhesives all day. Using a caulking gun requires a lot of repeated motion, so make sure that if you’re using one often you spend a little more to get a gun that is comfortable in your hand with easy triggering.
“The number one cause for residential construction litigation is water infiltration, so we have got to keep water outside of our buildings. There's a lot of different strategies for that, but one of the detail strategies that we use is caulking.” - Jordan Smith
Silicone caulking and other types of caulks and adhesives prevent water infiltration which is absolutely essential in construction. Just like any builder needs a hammer in their toolbag, you’ll need at least one caulking gun with a high compression ratio that can move thick (think: cold molasses) product at a steady rate. A good caulking gun allows you to apply the products that will seal out water properly. Water damage is a serious problem that can be very labor intensive, dangerous, and expensive to fix, so it’s best to do the job right the first time with the right caulking gun.
All caulking guns, from standard caulk guns to pneumatic caulk guns and sausage guns, are doing the same function—allowing you to push product out in a steady bead for easy application. The size of the product container determines what size and style caulking gun you will need. A 28-ounce gun takes a 28 ounce tube of caulk, a 10-ounce gun takes a 10-ounce tube, and so on.
When you picture a caulk gun, you’re most likely picturing a 10-ounce gun that takes 10-ounce packages of silicone that you can find at any hardware store. It’s fine as your standalone gun for DIYers, but professional builders may need a 28-ounce gun in addition to a 10-ounce gun.
This larger caulk gun will push a 28-ounce package, which means you’ll be changing out the product less frequently. This is considered a standard size for pros and many construction adhesives come in this size.
A sausage gun is a higher end gun made to distribute higher end products. It’s an essential tool for waterproofing. It’s called a sausage gun because the product comes packed in a tube similar to sausage packaging. Instead of the tip being on the product, it’s on the end of the gun and is reusable. Once you make the perfect cut on the tip once, you can use it over and over again.
While caulking guns are all relatively similar, there are important features to consider, and you should spend a little more to get a heavy duty version that can withstand constant use on the job site.
When you’re the one paying for the job site’s dumpster each time it needs to be emptied, you think about how much waste you are creating. One of the benefits of a sausage gun is that the foil that encases the product collapses into a small piece of waste the size of a hockey puck while traditional plastic tubes take up much more space in the dumpster. If you are doing a lot of waterproofing and going through hundreds of packages of products, this can add up quickly and you may want to go with the lower-waste option.
While a spout cutter might at first seem like a nice feature, Jordan points out that they often under-deliver. Sometimes they don’t work, they dull over time, and they don’t give you control over the cut of the tip. (Since forming the cut impacts how the product flows, you want control over how the tip is cut.) A cutter only cuts a square which will not give you the desired bead and flow—so you’d need to finish it with a quality utility knife anyhow.
A high compression ratio (also called thrust ratio) is a necessity if you are working with higher viscosity products. The higher the compression ratio, the more powerful the gun. Many adhesives we use now are closer to solid (high viscosity) so you need a powerful caulk gun to push it through. An 18:1 thrust ratio is a high rate that can handle super-thick products. You can get even higher with a 26:1 thrust ratio that would be necessary for working with extremely thick products like rubber.
The plunger rod that moves the product can be smooth or notched (also called ratcheted). With a notched rod, the trigger will engage with the notch and to disengage it you have to reorient the rod. Jordan prefers a smooth rod because it only takes the press of a thumb trigger to disengage making for a much cleaner and easier job. All of his recommended models below feature a smooth rod.
Make sure the gun comes with a seal puncture tool to pierce the seal of an adhesive. This step is less common with caulk but essential for adhesives because breaking the seal is what will allow the adhesive to cure properly.
A caulking gun is only one of the essential tools that you’ll need on a construction site. Learn more about caulking guns and other construction tools—and how to use them safely—in MT Copeland’s online Hand Tools class, taught by professional builder and craftsman Jordan Smith.
“Don't buy the cheapest caulk gun that you can get. This is one of the few instances where I would say the more you spend, the more you get.” - Jordan Smith
This 10-oz Rod Caulk Gun has a 13:1 compression ratio that is great for general purpose caulking speed and ease of triggering. The barrel swivels to allow for precise tip orientation when caulking around corners and it includes a seal puncture wire and ladder hook.
The HDX 29 oz. Heavy Duty Caulk Gun is the larger version of the 10-oz gun with all the same features including a 13:1 compression ratio, rotatable barrel, seal puncture wire, nozzle cutter, and ladder hook.
In either a 12:1 or 26:1 compression ratio, the Albion caulk guns offer professional builders the ultimate in durability and performance. Albion invented the smooth rod applicator and their current versions offer tremendous build quality and can be completely rebuilt as the tool wears over time. The 26:1 compression ratio is a must-have for polyurethane applications, especially in cold environments. It also features a rotatable barrel, seal puncture wire, and ladder hook.
The Newborn 620/AI takes bulk tubes or "sausage" tubes which offer the most product with the least amount of waste. This packaging is Jordan’s preference when dispensing waterproofing and air sealant. Also, since the nozzles are separate from the product packaging, you won’t need to reshape the nozzle after each reload. It also features an 18:1 compression ratio and an optimal ladder hook add-on.
The Milwaukee M12 Sausage Gun has all of the benefits of a sausage gun plus the perks of powered caulking guns. It features no triggering fatigue, reusable nozzle, ladder hook, and a comfort grip. Milwuakee's M12 battery system works across numerous tools and is much lighter than the M18 version with all the power you need for detail sealant work.
Get Jordan’s complete class on choosing and using essential construction tools in MT Copeland’s Hand Tools online course.
MT Copeland offers video-based online classes that give you a foundation in construction fundamentals with real-world applications. Classes include professionally produced videos taught by practicing craftspeople, and supplementary downloads like quizzes, blueprints, and other materials to help you master the skills.
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