DIY do it yourself? “FREE ESTIMATES”
There are numerous blogs on the internet that explain how to do DIY expansion joint replacement. We have rarely read one that was accurate. Often, the author misses the details crucial to longevity of the sealant. Preparation is the key which bloggers rarely touch on. We have found that bloggers seem more interested in providing a compelling story to drive website traffic than they are in telling “the entire story”. Bloggers claim it is simple to insert backer rod and apply sealant with a caulking gun without any real experience performing this task. Each project we do is unique and requires its own set of obstacles to overcome. Just bending over or working down on your knees on concrete is hard work, not to mention bloody knuckles from scraping the concrete while trying to remove old sealant or wood.
Grinding or power washing the interior joint wall is critical for sealant longevity. Dust must then be removed from the joint by compressed air and the joint must be completely dry. Backer rod is next to impossible to find at your local hardware store and when you find it, it is generally found to be too small. An average expansion joint ranges from ¾” to 1” in width and 4” deep. Mastic Masters carries 9 different backer rod sizes to accommodate the variety of joint sizes due to movement. This is also why prefabricated expansion joint products don’t work. If they do go in snug, they soon will settle down when the expansion joint contracts. Prefabricated expansion joints are required by the ACI (American Concrete Institute) to use a lubricant sealant to hold the filler in place and provide 100% water tight seal. See TrimGasket for more details as to the deficiency of pre-fabricated expansion joint fillers.
A consumer can buy a 29oz Tube of Sikaflex SL concrete grey sealant, with no other options in colors, at Home Depot, Lowes or Wal-Mart for about $12.98 a Tube. The package claims you get 12ft at 3/8 bead, meaning you get 3/8 width and 3/8 depth per Tube @ 12ft. As such, if you had a 1” joint, you would need ½” depth of sealant.
Therefore, you would need 3 Tubes to cover 12 ft of 1×1/2 expansion joint costing you $38.94 plus tax for just 12ft or $3.25 a ft. plus tax. This does not even cover the cost of backer rod or any other tools required to complete this project. Mastic Masters charges far less for the same work (taxes included) with a two year warranty and we come to you. We offer 80 color choices to match your concrete. What are you waiting for?
Joint Sealing is a necessity, not a luxury! Joint sealing is specified in every commercial expansion joint in every major city world wide. Your home and property should not be the exception. Sealing joints protect people and property from erosion, staining, trip hazards, pest invasions, splinters and it simply just looks better.
Sustainability is Concrete Repair!
What causes efflorescence and how do you remove it?
Efflorescence occurs with all concrete and is the most frequent problem that concrete contractors face with colored concrete. Owners don’t care about “plain” concrete, but colored concrete is another matter. They complain that their contractor didn’t give them the color they ordered, and sometimes they withhold payment. Efflorescence is caused when soluble salts and other water dispersible materials come to the surface of concrete and mortars. It’s induced by low temperatures, moist conditions, condensation, rain, dew, and water added to the surface of fresh concrete to assist troweling. It can occur very soon after exposure to moist or cool conditions or gradually, especially when it comes from within the concrete or from the subgrade.Any material containing portland cement results in efflorescence. The most usual reaction occurs when calcium hydroxide (lime) formed in the hydration reaction of portland cement (approximately 140 pounds per cubic yard of concrete) is transported by water to the surface through capillaries in the concrete. There it combines with carbon dioxide from the air to produce calcium carbonate (an insoluble material) and water. But efflorescence can also be caused by hydroxides and sulfates of either sodium or potassium, which are much more soluble in water than calcium. And they form efflorescence more rapidly than calcium hydroxide. These salts can come from cement, aggregates, water, or admixtures.Efflorescence is normally white and shows up more on darker colors than white or light gray because of the contrast. Only 0.2 ounce of calcium carbonate per square yard of surface is needed to cause a significant shift in color. Some forms are very difficult (if not impossible) to remove, while others are easy—especially if they are removed right after they form.
Removing efflorescence The easiest time to remove calcium hydroxide efflorescence is before it combines with carbon dioxide. Up to this time it will dissolve in water, so pressure washing or wet scrubbing will put it in solution with water so it can be rinsed away. You must be careful to rinse the surface with fresh water so that no residue is left to dry on the concrete. Use an air jet or a wet vacuum to remove any standing water. Any remaining solution will cause new efflorescence to appear.When efflorescence proceeds to the calcium carbonate phase, it becomes insoluble and is much more difficult to remove—perhaps impossible. The application of a mild acid solution becomes the first course of action. These acids include vinegar (5% acetic acid), muriatic acid, or citric acid. Muriatic acid is purchased in full strength and must be diluted. So it’s the most dangerous, requiring proper safety gear.After acid washing, slabs should be rinsed thoroughly and neutralized with baking soda (sodium bicarbonate) or an equivalent. Acid residues can harm plants. The reaction products of acid on concrete are all soluble calcium and iron salts, which can cause more efflorescence.When efflorescence can’t be removed with acid washes, other commercial products are available. One is ethylenediamine tetraacetic acid (EDTA), which rapidly dissolves calcium salts. EDTA will also damage concrete, so it’s best to test it on an inconspicuous sample area first.
Preventing efflorescence There are a few things you can do to reduce the possibility of efflorescence. Including either Class-F fly ash or metakaolin can lock up significant amounts of calcium hydroxide in the concrete. And as stated earlier, the efflorescence reaction is driven by water, either water from above or below a slab. Only vapor barriers can prevent the movement of moisture from the subgrade to the surface of a slab. And the application of sealers and coatings can prevent surface water from penetrating slabs. Apply them as soon as surfaces are clean and dry.
WATER PROOFING & PROTECTION
Expansion joints are an integral part of concrete structures. They are built into deck systems to control the stresses of volume changes in concrete. Depending on the type of construction (cast-in-place, precast, etc.), joints are installed to isolate ramps, buildings, and large expanses of deck surface. They may also be needed to provide free rotation of deflecting members. Most joints open and close according to daily and seasonal fluctuations in deck surface temperatures.
Joints provide a natural place for water, salts, and debris to collect. They also present a hazard to pedestrians who may trip over them. To prevent these problems, joint seals can be installed. Sealants must be designed for the intended movement of the joint, as well as for water-tightness, wheel action (traffic, equipment), pedestrian safety, and repairability.
Waterproofing and protection techniques are used to control deterioration of structures. These techniques alter service or exposure conditions, enhance physical properties, install barriers, alter electro-chemical behavior and halt water infiltration.
Waterproofing and coating techniques prevent water from entering or exiting a structure through cracks, joints, or failed waterstops. These protection techniques extend the time duration between maintenance cycles.
Choosing appropriate techniques requires an evaluation of factors such as cause/effect relationships, useful life, constructability, environment, aesthetics, and cost-benefits. MasticMasters has the experience necessary to perform the best applicable waterproofing and protection techniques based on the particular project and service requirements.
HOA approved and recommended