Yes, concrete control joints should be caulked. Caulking is frequently required to keep moisture from penetrating the concrete slab’s base. It also helps to keep dust, weeds, bacteria, and pollutants from endangering people’s health, affecting aesthetics, and causing structural damage.
Concrete control joints are those thin strips of concrete that run perpendicular to a wall’s surface. They serve as an expansion joint between two adjacent slabs, and they can be caulked or sealed with silicone.
But which is better for the structure?
You’ve probably noticed them if you own your home. These small strips of concrete running parallel to walls in public spaces like hallways have become ubiquitous throughout modern society.
You might even see one near where you work; these “concrete control joints” act as expansion joints between two adjoining sections of poured concrete flooring — basically allowing each floor segment to move slightly relative to its neighbor without causing problems such as cracking or breaking.
While we often take this tiny strip of cement for granted, there are actually several benefits associated with having a properly designed concrete control joint system installed around our homes.
First off, since concrete expands and contracts more than any other material used on earth (except steel), pre-stressed concrete control joints allow us to avoid cracks and breaks when settling occurs over time. This means less money spent fixing things later down the road and potentially longer livability for your home thanks to improved structural integrity.
And although it may seem counterintuitive, concrete control joints also help ensure greater energy efficiency because they allow more heat transfer through a building envelope during hot weather months. Lastly, concrete control joints provide additional protection against water damage, which is especially important in basements and crawlspaces. After all, no good house should go up in flames!
So what exactly are concrete control joints made from?
As mentioned earlier, they’re usually comprised of two pieces of poured concrete fitted together tightly by grouting. The space created between these two layers serves as the actual gap across which settlement takes place.
Typically, both sides are filled with sand, gravel, or crushed stone, but sometimes only the top layer is filled, depending on the location.
If so, then the bottom layer would simply need to be left open and free of obstructions. Once these two pieces are glued together using either mortar or adhesive, reinforcing rods, wire mesh, or rebar are inserted into the middle of the mixture to strengthen the entire assembly.
When reinforcement isn’t added, however, the resulting gaps aren’t particularly strong. Over time, therefore, concrete control joints should be regularly inspected for signs of wear and tear, including mold, moss, discoloration, and crumbling, before calling for repairs.
The second type of concrete control joint utilizes flexible rubber pads instead of rigid materials. Although they look similar to standard concrete control joints, these systems use polyurethane foam rather than hardening agents like masonry mortars.
Flexible pads allow for movement while still providing excellent thermal insulation properties and soundproofing capabilities. Since these devices cost significantly less to install, they tend to make sense economically speaking.
However, research has shown that conventional concrete control joints offer superior durability compared to their counterparts, which makes this decision somewhat dependent upon local conditions [Source: ASHI].
In addition to choosing between caked vs. caulk sealants, homeowners must decide how much risk they’re willing to assume regarding potential health issues related to volatile organic compounds (VOC) emitted by silicones.
For example, many people choose not to apply caulk to concrete control joints out of fear that VOCs could cause cancer. While scientists haven’t yet confirmed these claims, experts agree that ventilation plays a crucial role in minimizing exposure risks.
So next time you’re considering sealing your concrete control joints, consider installing a new set of windows!
There are three main types of concrete control joints, based on their installation methods:
Sandstone control joints consist of a vertical plate mounted onto a horizontal base plate, secured via anchors. A space exists between the plates, and this area is filled with sand, gravel, or crushed stones. Reinforcing bars are positioned within the gap to create a stronger connection.
Sandstone control joints are typically found in commercial buildings and high-rise office complexes.
Rubber pad joints utilize a series of interconnected inflatable bladders called cushion units. Each unit consists of a pair of air chambers separated by a porous membrane, and inflation valves are located at opposite ends of the device. To construct a complete system, multiple units are connected end-to-end so that they fit snugly together, creating a continuous barrier.
Rubber pad joints generally come equipped with integrated drainage holes to prevent fluid buildup inside. Because they don’t require anchoring mechanisms, owners can easily relocate these systems when necessary.
Additionally, since they rely heavily on pressure to maintain proper spacing, they can handle larger movements more gracefully than traditional concrete control joints. Finally, unlike regular concrete control joints, these pads won’t crack due to shrinking caused by freeze/thaw cycles.
Beaded joints, also known as beadline joints, consisting of rows of beads attached horizontally alongside a wall. Beads are long metal rings that are placed side-by-side until enough length forms to cover the desired width of the gap.
Then, the entire assembly is covered with sand, gravel, or crushed stones. Similar to rubber pad joints, bordered joints operate using compressed air to maintain separation between neighboring surfaces.
However, just like sandstone control joints, they do not include internal reinforcing structures. Instead, bead line joints are held tightly together by gravity alone.
Another type of caulking system used is the latex rubber-based emulsion system. Which will be discussed below in detail.
How To Caulk Concrete Control Joints?
There is one simple question that you should ask yourself before getting started caulking concrete control joints – what type of caulk do I use for my application?
It may be tempting to go with any old kind of caulk as long as it “seems like” some people have used it successfully on their projects, but this approach can prove disastrous once you start digging deeper into how these products work.
The only way to know if your choice will actually perform well under extreme conditions is by conducting proper research first. In order to help you narrow down your search for the right product, we’ve compiled several useful tips below.
1. What is the most common material used for making the joint spacer beads (filler) in concrete control joints?
One of the main materials used today for making joint spacers is silica sand. Silica sand has been widely used throughout history due to its relatively low price and high availability.
Despite being inexpensive, however, silica sand does not offer much resistance against chemicals such as acids and alkalis. As such, it cannot protect the underlying asphaltic surface when exposed to road salt during the winter months.
2. Is there any other cheaper alternative to using silica sand for creating concrete control joints?
If so, what would those alternatives consist of?
The second most commonly used material for creating filler in concrete control joints is calcium chloride. Calcium chloride is a naturally occurring chemical found abundantly in many soils across Canada, US & UK.
Due to its natural origin, calcium chloride offers excellent acid-neutralizing properties. When mixed together with cement, calcium chloride creates small air bubbles within the mixture which ultimately reduces the amount of time required for setting.
This allows contractors to finish paving faster than they normally could without having to worry about the curing period of the mix. Another benefit of the addition of calcium chloride is that it helps prevent cracking.
Finally, calcium chloride provides good adhesion to both cements and bitumen-based binders. For all these reasons, calcium chloride has become increasingly popular over the past few years.
At present, calcium chloride is usually sold as an aggregate substitute at 50% less cost per tonne than silica sand. However, these savings must be balanced out against potential health risks associated with the use of calcium chlorides, such as eye irritation and skin rashes.
Therefore, it is important to weigh up the pros and cons of each option carefully before deciding upon your course of action.
3. How effective are different types of latex rubber-based emulsion systems compared to others?
Latex Rubber Emulsions come in three forms; Dry Latex, Waxy Latex, and Poured Latex.
Each type has unique characteristics and uses. We’ll take a closer look at them here:
Dry Latex – Dry latex consists of solid particles suspended in the liquid oil. These particles act as fillers or thickeners in various applications including flooring, paint, cosmetics, and food products.
Unlike waxy latex, dry latex tends to produce more gel strength than other types of latex because of its higher concentration of solids. Its performance is also unaffected by temperature changes.
Although dry latex is generally safe to handle, caution needs to be taken when mixing. Excessive dustiness while handling is often caused by poor ventilation.
Lastly, although latex paints tend to last longer than those made with conventional resins, latex paint still requires frequent touch-ups after installation.
Waxy Latex – Like dry latex, waxy latex consists mainly of oil-soluble polymer polymers.
However, unlike dry latex, waxy latex contains no solids. Instead, waxy latex acts as a binder in numerous industrial applications including insulation board, roof coatings, plasterboard, carpet backing, adhesive tapes, and caulks.
Because of its flexibility, waxy latex works best when installed directly onto wood surfaces. Other benefits include better durability, lower maintenance costs, and improved bonding with metals and plastics. Unfortunately, waxy latex is highly susceptible to oxidation.
Oxidation causes unsightly blemishes, fading, and even complete discoloration. Fortunately, since waxy latex is applied topically, the problem may easily be fixed through simple cleaning.
Also, keep in mind that waxy latex can stain clothing, gloves, and shoes.
Poured Latex – Similar to waxy latex, poured latex refers to a variety of synthetic latexes which are manufactured specifically for painting purposes.
Common brands of pourable latex range from ultra-fine grades used primarily for interior finishes to thicker grades designed for outdoor exposure. Since Poured Latex is thinner than other latex options, it is recommended for indoor use only. Pourable latex solutions are prone to yellowing over time.
Yellowed areas indicate excessive sun damage. Before applying such paints, make sure you wear protective gear. In case of accidental spills, immediately clean up the area thoroughly using soap and warm water.
Do not allow spilled paint to remain on the soil. Wear disposable coveralls or protective clothes to avoid contact with the solution.
4. Are there any special considerations in terms of choosing among different types of latex?
Yes! There certainly are.
First off, consider whether you’re looking for exterior grade latex or interior grade latex. Interior grade latex is intended for use indoors whereas exterior grade latex is meant for direct outdoor usage.
Both types of latex differ significantly in terms of quality, functionality, and longevity.
Second, ensure that you choose a brand that suits your specific project requirements. Thirdly, make certain that you get hold of samples in advance. Samples help you determine which type of latex might serve your purpose best.
Last but definitely not least, make absolutely sure that you follow manufacturers’ recommendations regarding preparation techniques. Proper prep ensures optimal results and avoids unnecessary waste.
5. Are there any advantages/disadvantages related to using multiple layers versus single layer latex caulk? Why?
Advantages of using multi-layered latex caulk include ease of application, increased coverage, and protection against UV rays.
Single layered latex caulk comes pre-applied to form a thin film which means a greater chance of leakage. On the contrary, multi-layered latex caulk has superior elasticity allowing for easy stretching around irregularities.
Multi-layered latex caulk is also resistant to tearing and ripping thus ensuring enhanced overall durability. Disadvantages of using multi-layered latex caulk include difficulty in removing excess latex and risk of contamination.
Removing too much latex can result in smearing which makes subsequent removal very difficult. Contamination occurs when latex drips or seeps from cracks located above the finished level. While removal can sometimes be done manually, it is far easier to let the latex cure completely and then remove it mechanically.
6. Can latex caulk ever be painted? If yes, why would you want to do that? If not, why?
No. You wouldn’t want to paint latex caulk simply because latex caulk shouldn’t be painted.
Paint doesn’t adhere well to latex caulk nor does it bond properly resulting in peeling and chipping. Furthermore, latex caulk isn’t suitable for coating metal substrates. That said, latex caulk can be coated with the epoxy resin prior to installation thereby providing additional weatherproofing capabilities.
7. Does latex caulk shrink or swell according to climate change? If yes, why?
Yes, latex caulk does expand according to humidity levels.
Most likely, this happens because of the evaporation of solvent contained within the latex. Expansion can occasionally lead to splitting along seams, especially where the installer hasn’t allowed sufficient space for expansion.
Nevertheless, latex caulk expands minimally and rarely leads to gaps forming at seam locations. Secondly, latex caulk swells slightly in response to heat and cold temperatures.
This effect is most noticeable when installing latex caulk outdoors. Swelling can cause problems such as difficulty in placing caulk precisely.
Thirdly, latex caulk remains unaffected by environmental factors such as rain showers. Fourth and finally, latex caulk won’t react to seasonal variations. All told, latex caulk is extremely durable and reliable.
8. Would latex caulk require patching? If yes, why?
Patchy latex caulk is typically seen in cases where the installer didn’t prepare the substrate adequately. Patching latex caulk is not necessary unless the installation was performed incorrectly.
9. Should I use waxed paper or plastic sheeting underneath the latex caulk before laying it down?
It depends largely on the thickness of latex caulk and the nature of the surrounding environment. Generally speaking, if the substrate is porous enough, waxed paper suffices.
Otherwise, plastic sheets are needed. Please note though, that neither method guarantees a 100% success rate.
Concrete joints are those thin strips of concrete that run perpendicular to a wall’s surface. They serve as an expansion joint between two adjacent slabs and can be caulked or sealed with silicone.
Concrete control joints should be caulked which also helps to keep dust, weeds, bacteria, and pollutants from endangering people’s health. They’re made up of two pieces of poured concrete that are glued together using either mortar or adhesive and reinforced with reinforcing rods, wire mesh, or rebar to create a solid foundation.
Beaded joints, also known as beadline joints, are made up of rows of beads that are attached to a wall or floor using metal rings.
It can be difficult to know which product is best for creating joint spacer beads (filler) in concrete control joints. Silica sand, calcium chloride, and other materials are some of the most commonly used alternatives to silica sand for making joint spacers. A latex rubber emulsions system is also applicable.
Latex rubber emulsions come in three forms; Dry Latex, Waxy Latex, and Poured Latex. Each type has its own unique characteristics and uses, so it’s important to consider the pros and cons of each before deciding which is best for you.
Poured latex refers to a variety of synthetic latexes which are manufactured specifically for painting purposes. The latex caulk can be coated with the epoxy resin prior to installation for additional weatherproofing capabilities.