Blacktop Crack Filler
The best blacktop crack filler is epoxy. You embed stones and sand in the fresh epoxy to completely hide the crack.
Blacktop Crack Filler - Use Epoxy and Small Stones
DEAR TIM: I've struggled for years trying everything to permanently fill aggravating cracks in blacktop. The magic caulks sold at the big boxes have provided me with dismal results.
The worst part is no matter what I try, sometimes the repair looks worse than the actual crack. The repair material stands out like a sore thumb.
Have you had any luck fixing blacktop cracks so you can't see them? Do the repairs last? What magic secrets can you share about the process? Kathy Z., Mills River, NC
DEAR KATHY: I used to struggle with blacktop crack repairs too. When I was in college I started a house painting business with a good friend.
One homeowner asked us while we were painting her house if we could seal her blacktop driveway. Never having done it before, we said "Yes" and figured it couldn't be that hard.
What is the Worst Blacktop Crack Filler?
The worst blacktop crack filler is a mixture of sand and blacktop sealer.
The drive had some cracks so we just mixed up some sand with the liquid blacktop sealer and poured that into the cracks. While the sealer job came out great, the crack-filling experiment ended in a dismal failure.
Over the years, I've tried many different products looking for the Holy Grail of crack fillers. It just so happens I believe I may have found it.
Why Do Crack Repairs Look Bad?
The crack repair looks bad in most cases because the repair doesn't match the color and texture of the adjacent blacktop.
I know what you mean about the repair looking worse than the crack. When a new blacktop drive is installed, it's jet black. This is because each piece of stone and sand in the mix has been coated with the black asphalt cement that's the glue holding the stones and sand together.
Why Doesn't Blacktop Stay Black?
Over time, Mother Nature washes away the black asphalt from the surface and you see the different colored pieces of stone and sand. When you then fill the crack in your blacktop with a monotone-colored product such as deep-black caulk, you bet that black line stands out like a sore thumb.
Do The Black Crack Fillers Last?
My second-last blacktop crack filler was a special caulk that had small pieces of silica sand in it and was extremely sticky. I installed some on my drive five years ago and it looked pretty good after three years, but then it started to succumb to the stresses of harsh New Hampshire winters and the punishing ultraviolet rays of the sun.
When I installed it, I did push some small stones into the gooey caulk to help disguise the repair, but you could still see it if you looked closely. Here is a video I taped showing using the inferior blacktop crack filler in a normal caulk tube:
What is the Best Blacktop Crack Filler?
I believe my quest for the best blacktop crack filler has come to an end. Based on a test I just did at my own home, I do believe I've discovered the Holy Grail of blacktop crack filler material.
The material is a semi-liquid epoxy that's in a regular caulking tube. It's battleship grey in color and it does contain very fine silica sand in it. The caulk-tube design is unique because it comes with a long nozzle that blends the two epoxy components as you squeeze the caulk gun handle.
Most epoxies have very high tensile strength and can resist strong pulling or bending forces. This makes them ideal for blacktop crack fillers because asphalt is a flexible pavement that does move.
How Do You Repair The Crack?
Using this material is caveman simple. You simply cut off the tip of the caulk tube above the threads, screw on the long nozzle and start to squeeze the gun handle. You can see the two-part epoxy start its journey down the nozzle and it mixes as it travels to the tip.
Do You Have to Use All the Epoxy at One Time?
No, the epoxy comes with two handy long nozzles. This allows you to use the material two different times on different days. The two components don't get hard at the end of the caulk tube because they've yet to mix.
How Deep Should the Crack Be?
The secrets to success are simple. I made sure my driveway was dry and I brushed out the cracks removing all debris to a depth of 1 inch. I allowed the sides of the crack to dry. While doing this, I spent time along the edges of my driveway gathering loose clean stones.
How Big are the Stones?
My mission was to collect stones of all different sizes and colors that matched what I saw in my blacktop. The size of the stones ranged from lima bean down to the size of a peppercorn. I also swept up a generous amount of clean sand from my driveway.
How Much Epoxy Do You Use?
I applied the epoxy carefully into the crack making sure I left it about an eighth of an inch below the surface. I found it best to caulk about one foot of crack at a time.
When Do You Install the Stones?
I carefully embedded the stones into the fresh epoxy pushing them into the product making them flush with the adjacent stones. I made sure to mix the stone sizes so everything looked like it was original.
How Do You Fill Deep Cracks?
You don't have to fill deep cracks all the way with the epoxy. To save money, squirt some in, add a layer of stones to take up space and then squirt in more epoxy.
Think of it as a layer cake of epoxy, stones, epoxy, stones, epoxy and then the last layer of stones that are flush with the rest of the driveway.
When Do You Install the Sand?
Once most of the epoxy was covered with stones, I then broadcast the sand over the crack. The sand completely hid the gray epoxy making it invisible. I'm very confident I'll not be repairing any blacktop cracks for a very long time! Try it yourself and see.