Caulk products serve a number of functions around the home, but it all boils down to filling gaps. Whether you’re filling joints between two materials for aesthetic reasons or you’re filling gaps in your home to prevent air or water infiltration, the application of the product is usually made in the same way.
Not all caulks are created equal, however, and you should pay attention to the properties of the product you purchase. These days, caulking products are made from a wide range of materials, including silicone, acrylic, siliconized acrylics, latex, co-polymers and more.
The easiest and fastest way to achieve a nice, crisp caulk line is to stop by the hardware store, purchase the cheapest acrylic caulk on the shelf, and lay the bead. These cheap caulks are easy to shape and easy to clean up (not sticky like silicone). In practically no time you can fill that crown moulding joint and take a photo of your beautiful work. And it’s a good thing you’ll have that photo to remember it by because within a year the caulk bead will likely dry out, shrink and develop unsightly cracks. Check out Hitch Property Constructions for a huge range of Melbourne caulking services
The problem lies in the cheap caulk’s inability to stretch, coupled with the surrounding material’s tendency to expand and contract with moisture and temperature changes. The crown moulding moves, the caulk doesn’t, so the bead cracks, looks ugly, and you have to re-caulk it within a year.
To avoid this, choose a better caulk product. Rather than committing to memory the various chemical names for ingredients, pay attention to the indications on the label. Look for words like “elastomeric” and “flexible” which means the bead will bend and stretch in lieu of breaking when the surrounding substrates move. The company Sashco makes a water-based caulk/sealant called Big Stretch that will twist, bend, compress and stretch more than 500 per cent of the original size.
5 Steps To A Successful Caulking Project
If there’s some caulking work to be done around your home, but you’re not experienced with a caulking gun, take some time to look over these simple steps required for any successful caulking project.
If you’re an old pro at caulking, come see us at Maxwell Supply in Tulsa to pick up all the supplies you need.
Choose the right caulk.
The caulk you need to use depends entirely on where you’ll be using it, and what your goals are for the project. The most common use is to keep air and water out, but there are many types of caulk that can get the job done. Your best bet for a long-lasting seal is using 100% silicone caulk, which is waterproof, flexible and shrinks and crack proof. The dangers of other types of caulk, like acrylic, is that over time, they tend to shrink or crack, which makes your seal fail. If you’re planning to paint the caulk after sealing, be sure you purchase caulk specifically made for that. And, if you’re planning to use it in one specific area of the house, look for varieties like Window and Door caulk, or Kitchen and Bathroom.
Clean up first
Before you can start installing new caulk, you need to clean the surface. That means not only removing dirt, and any other particles present, but also completely removing any old caulk in place. A caulk removing tool or a wire brush will be vital here. You’ll then want to place masking tape on either side of the surface to ensure a straight edge, but be sure you remove it immediately after applying your caulk. Check out our Melbourne caulking services here.
Now your surface is ready to sell, but you’ll need to prepare the tube of caulk first. The size of the bead you apply depends on how you cut the nozzle on the caulk tube, so do so carefully. Then, puncture the inner seal on the tube with whatever you have handy. A stiff wire works great. You can now insert the cartridge into your caulking gun and begin sealing. Be sure to apply even, constant pressure to the gun’s trigger so your caulk will exit the tube at an even rate.
Smooth it out
Let’s face it, if this is your first time using a caulking gun, you probably won’t apply the caulk completely evenly and perfectly. That’s OK. Even pros need to smoothing tool, or their finger, to ensure the bead of caulk is smooth and clean. To fix any mistakes that were made along the way, be sure to smooth the caulk two to five minutes after application. It needs to set slightly, but letting it set too much makes it impossible to smooth out.
Clean up and prepare for next time
If you’ve got caulk leftover in the tube, you can’t just put it aside and expect it to be usable when you need it next. Squeeze the tube until there’s the slightest bit of caulk coming out of the nozzle, then replace the cap, or insert a nail to keep the opening, well, open. If there’s caulk around your surface that needs to be cleaned, mineral spirits are great for cleaning up silicone caulk.
Successful Way Of Caulking
Watch the Weather
Pay attention to the weather, as it can affect:
- the size of the joint at the time of caulking (cold weather cause the joint to expand, while warm weather cause the joint to shrink)
- the contaminants on the surfaces of the joint (like dust, pollen, old caulk, etc.)
- the ability of the caulk to “wet” the surfaces of the joint for good adhesion
- the ability of the caulk to properly cure and develop its ideal physical properties
Ideal Weather Condition
Plan to caulk in ideal temperatures whenever possible. What is ideal? 40°F and rising and 90°F and falling. Be sure to pay attention to the surface temperature where you’ll be applying the caulk. It should also fall within that ideal temperature range. Some caulk, Like Sashco’s Lexel® and Through the ROOF!®, can handle more extreme temperatures during application (0°F to 120°F) and will still perform.
When using water-based caulks, allow the surfaces to completely dry before caulking. Wet surfaces will make proper adhesion difficult and may inhibit proper curing of the caulk. In the same way, avoid applying water-based caulks – even in ideal weather – if rain or snow is expected within 24 hours. If you need to get the caulking done, go ahead and do it. Just make sure to cover your work with a plastic tarp to prevent moisture from getting onto the caulk and causing it to wash out.
Sashco’s Lexel and Through the ROOF! Can be applied to actively wet surfaces. If you need a product in the middle of a rainstorm, these are what you need. If the surface is frosty, remove the frost first by wiping it down with denatured alcohol.
It is never good practice to apply the caulk in extreme temperatures. Whether hot or cold, the joint will not be at its ideal size, the caulk will not cure correctly (which causes performance problems), or the caulk may develop blisters. Any weather-related problems with the caulk can be fixed fairly easily, but are also avoided altogether through simple weather watching.
Prepare Surfaces & Joint for Sealing
Prepare the surface and clean out the old caulking. Good surface and joint preparation is the #1 requirement for a professional and long-lasting caulking job, whether you’re replacing old caulk or sealing a new joint for the first time. Here’s how to go about cleaning:
- Use a putty knife, painter’s 5-in-1 tool or another similar tool to remove all of the old caulk in the joint. A heat gun can be used to soften old caulk and loose paint to make removal easier, or caulk remover can also help remove all types of old caulk.
- Make sure the surface is completely free from old caulk, peeling paint, weathered wood fibres, grease, oil, wax, pollen, dirt, rust, mold, mildew, soap scum, etc. A wire brush works well to remove contaminants, and a drill-mounted wire wheel is often the best answer for cleaning dirty, unsound concrete. To clean off oil or grease, use a grease-cutting cleaner and thoroughly rinse. Remember, the best caulk in the world won’t work if it is applied to a dirty or unsound surface.
- Finally, ensure the surface is rinsed clean if you used a chemical remover. Chemicals can also interfere with proper adhesion.
Use Pre-Caulking Filler Rope
Use Backer Rod Instead of More Caulking. If the joint or crack will be 1/4″ wide or more and 1/2″ deep or deeper, it is best to install Filler RopeTM or a similar foam backer rod in the joint before applying the caulk. Why use Filler Rope?
- It saves money. Filler Rope and other backer rods are much cheaper than filling the joints with caulk.
- It helps provide the ideal joint design (two points of adhesion with less product applied in the middle of the joint), which provides for best elasticity and easy fixes when there is extreme movement, and the joint widens more than the caulk can handle. For more info on the proper joint design, see Sashco product brochures.
- Tooling is improved. More pressure can be applied to the caulk when Filler Rope is behind it. This added pressure forces the caulk into intimate contact with the sides of the joint for better adhesion.
How to Install Filler Rope
Simply press the material into the joint using your hands or an appropriately sized blunt tool. It should be shoved deeply enough to allow the caulk to be 1/4″ – 1/2″ deep when applied over. If you are using a closed-cell backer rod, avoid putting holes or nicks in it because the damage can lead to “out-gassing” from the backer rod and may cause blisters in the caulk. Then, masking tape or painters tape can be applied to both sides of the joint before caulking to prevent smearing and to create a clean caulk line.
If the joint or crack will be subjected to regular difficult stress, such as continual water submersion at the bottom of a swimming pool or a home in extreme wind, it is important to use a primer before caulking. For a home, normal paint primer will do the trick. In a swimming pool or other unique situation, contact us for recommendations. The caulk will adhere better to the primer, giving it better long-term performance and will require less maintenance over time.
Why Caulking Fails
Think about the exterior caulking jobs you’ve seen over the years. How many are still keeping water out 5, 3 or even two years after application? Probably no more than half do what they’re supposed to do for the long haul, and that means the premature failure of building envelopes as water seeps into places where it shouldn’t be. Regardless of the product involved, the cause of exterior caulking failure is almost always the same: poorly managed expansion/contraction issues. Caulking manufacturers have remained almost completely silent on this at the retail level, though you have to wonder why since lack of understanding makes so many caulking installations fail. Maybe they think the public isn’t prepared to sit still long enough to appreciate the subtleties involved. Maybe caulking performance doesn’t have enough to do with sales. Hitch Property Constructions has a wide range of caulking services. Whatever the reason, it’s the same old story. If you want top-notch results, you have to educate yourself beyond common knowledge and see that things are done correctly.
If every caulkable joint were completely stable all the time, then successful exterior caulking installation really would be as simple as it seems. But that’s not the case. Caulkable joints, especially exterior ones, almost always expand and contract substantially with changes in temperature (and sometimes humidity), especially where different materials flank the joint. And unless you make allowances for this inevitable movement, even the most flexible caulking products on the market will fail.
Although wide joints are good because they don’t overload the elasticity of caulking, they can also gobble up caulking way too fast if they’re too deep, as they often are. That’s why there’s something called a backer rod. These lengths of flexible foam usually cylindrical in cross-section are designed to be stuffed into gaps before caulking is applied. You’ll typically find a backer rod in diameters ranging from 1/4-inch to 7/8-inch, though it does get as large as 4 inches in diameter. The uncompressed backer rod should be 25% larger than the gap it fills (or the next size up) and stuffed far enough in so the depth of the gap is half of its width, down to a minimum of 1/4-inch deep and a maximum of 1/2-inch deep. Why the depth limitations? Besides reducing the amount of caulking, you’ll use, limiting caulking depth with backer rod has to do with flexibility again. When the depth of a bead of caulking exceeds its width, it becomes more difficult for the product to stretch as much as it’s rated to, without pulling away from the sides of the joint area. Too deep is not good.
This is all fine, as far as it goes, but how often do you have the luxury of determining the width of joint you need to caulk? Not often enough. That’s why the people wearing white lab coats invented something called bond breaker tape. This self-sticking tape, often made of polyethylene, is applied over or across under-width joints. The purpose of a bond breaker is to prevent adhesion of caulking in a specific area. In the case shown in the illustration, this spreads the joint movement over a wider area of caulking, resulting in a less crack-prone joint. Electrical tape is a pretty good substitute for proper bond breaker tape.