How to fix marble countertop cracks permanently
This Comprehensive Guide to Repairing Marble Countertops Includes Fixing Cracks
Marble counters are beautiful and durable, but marble is made of stone and can be broken. If there is a sufficient amount of force applied to the surface of the marble (resulting from things like thermal expansions/contractions, structural movement, or improper installation) it is likely to result in cracking of the surface.
Before you can effectively repair cracks permanently, you need to evaluate and identify the type of crack that you have and the underlying cause of your cracks provides you with necessary information to properly determine which methods and products will be used to repair your cracks.
1. What Types of Cracks do you have?
The first step to repairing your countertop surface cracks is to identify the different types of cracks that are located in your countertop surface.
Crack Classification(s):
1 – Surface Hairline Crack(s)
1.1 – Visible only through magnifying glass (very thin).
1.2 – All edges of the cracks are level.
1.3 – Mostly cosmetic crack(s).
2 – Cracks caused by Movement
2.1 – Visibly separated.
2.2 – Movement within the slab located inside the crack(s).
2.3 – May continue all the way through the slab (top surface through bottom surface).
3 – Impact Crack(s)
3.1.- Dropped a heavy object on top of marble slab resulting in crack.
3.2.- Radiates out from point of impact.You should first repair any cracks in order to fix, or address, any structural problems stemming from them which is causing them. If you don’t completely resolve the initial problem, any solutions you provide will fail to last, and you will see another crack develop. Choose the correct material to repair:
Structural Repair – Knife Grade Epoxy
– This type of product has a good adhesion factor and is non-sagging;
– Knife grade epoxy can be dyed to match existing marble or another “closed surface”;
– Knife grade can also be polished after setting, if cured.
Hairline Cracks – Flowing Epoxy
– Flowing epoxy will fill hairline cracks and provide reinforcement from the interior;
– Flowing epoxy can be used for numerous close hairline cracks as well.
Polyester Resin – DO NOT USE!
– Polyester resin cures faster but has a lower “adhesion” factor and an increased likelihood of being discolored (yellow).
If you are looking for a material to create a permanent repair, epoxy is the best solution for adhering permanently to natural stone because of its superior adhesion compared to other materials and resistance to moisture and thermal fluctuations.
To prepare the crack for repair(s):
The manner in which you prepare the crack(s) will indicates the longevity of your repairs.
How to prepare the crack:
-Clean all dirt and grease from the crack using acetone;
-Remove any and all “loose” debris from within the undamaged area of the crack using compressed air;
-If required, slightly widen the crack to allow the epoxy to penetrate by using a razor blade;
-Back tape surrounding areas of the repair to avoid accidental staining from applied adhesive;
-Ensure the crack you wish to adhere to is completely dry prior to applying adhesive.Applying the epoxy would involve the following steps for filling in hairline cracks:
Using a syringe, inject low-viscosity epoxy into a hairline crack.
Ensure that enough time has elapsed for the epoxy to saturate through the exterior of the slab into the hairline crack.
Remove any excess material prior to the epoxy curing.
Applying the knife-grade epoxy would involve the following steps for larger structural cracks:
1.) Match the color of the epoxy (knife-grade) with that of the marble surrounding the repair site.
2.) Mix in color with the knife-grade epoxy and force (using a putty knife) the epoxy into the crack while overfilling just a bit to allow for sanding after the epoxy has cured.
3). Work within the manufacturer’s recommended temperature range (18-25 degrees Celsius or 64-77 degrees Fahrenheit) to provide the epoxy with the proper curing environment (as each manufacturer of knife-grade epoxy has their own unique curing temperature, be sure to read and follow all curing instructions provided by the manufacturer on the packaging.)
Step 5: Reinforcement Beneath
Providing support for the underside of the crack is critical to maintaining the stability of a deep-crack marble-countertop, as it will not move out of position over time.
Ways that a professional installer may reinforce the underside of the crack include the use of fiberglass mesh on the back of the slab, attaching steel/stone support brackets beneath the slab for support, and using structural epoxy (or some variation thereof) as an added support on the/to the underside of the slab.
If you have installed a cabinet and have caused an alteration in the structural integrity or potential for cracking of a marble countertop, be sure to adjust the cabinet back to its original position before proceeding with the final repair.Step 6 – Sanding and Polishing
Once the epoxy has completely cured (usually within 24 hours since being installed) you need to: – First sand using wet sandpaper in the range of 400 grit to 3000 grit, then gradually increase the size of each successive piece of sandpaper until reaching 3000 grit; – When you are finished sanding use a polishing compound to bring the repaired area back to the same luster or shine as the surrounding un-repaired areas; – If you polish the repaired area correctly, it will be virtually undetectable after having been polished.
Step 7 – Seal New Countertop
After completing the polishing process, apply a high quality sealer to the surface of the new marble countertop and allow the base material underneath to cure before using this countertop. Sealing the new countertops will prevent moisture from penetrating through the surface of the new marble and/or through any areas that have previously been repaired.
When Should I Contact A Professional Installed Marble Countertop Repair Company?
There are times when it would be beneficial for you to have a professional marble countertop repair company perform repairs related to your purchased marble countertop.There are a number of situations where an experienced repair professional is necessary:
– If the crack extends completely from one side of the slab to the other.
– If the marble is either white or translucent and a color match is hard (or impossible) to obtain commercially.
– If the countertop will be subject to heavy load (for example, an island countertop with a cantilevered section); and
– If the crack continues to open up, you should contact a marble countertop repair professional immediately for help.
Stone fabricators generally perform seamless repairs by utilizing vacuum epoxy systems and industrial polishing equipment that yield exceptional results on cracks.
Common Errors You May Encounter When Trying to Repair Your Cracked Marble Countertop
1. Never use super glue for crack repairs (super glue is only intended for temporary use).
2. Always clean the area to be repaired thoroughly before applying any epoxy.
3. Do not forget to adjust cabinet supports appropriately prior to initiating your repair.
4. Never sand on an area that has not been cured.
5. Never use polyester resin on high-quality marble.
Longevity of Repairs
Repairs performed correctly using structural epoxy will last 10-20 or longer (depending upon proper installation due to proper specification compliance and reinforcement adequacy). Determining factors affecting longevity include:
1. Surface area was prepared adequately.
2. An appropriate epoxy adhesive was used.
3. There were adequate cabinet support.
4. The repair was polished adequately.
Final Thoughts
If done properly, using the right materials and procedures, marble countertop cracks can be repaired permanently. When epoxy is part of the material of choice used to repair your cracked marble countertop, that countertop’s life span will greatly exceed those made from other materials, particularly when proper structural support methods are used.
In addition to restoring the original beauty of a marble countertop through successful repairs, good repairs will protect your investment for many years.
