This project is continued from Part 1.

The crack in the outside corner of the patio slab was filled with sand to within 1″ of the surface forming a channel to hold the Emecole 555. Some run out from the side of the slab occurred, but not so much that I though it too wasteful.

Repairing Cracked Concrete Slab Corner with Emecole 555

I made three passes over the crack, refilling the channel with the Emecole 555 as the material soaked into the crack. A cartridge of Emecole 555 is normally good for 100ft to 200ft of narrow cracks, I had now emptied over half the cartridge into a 7 foot long, wide crack in the 6″ to 10″ thick concrete slab.

Third Pass over the Concrete Slab Crack with Emecole 555

The channel was topped off with more sand to soak up the Emecole 555 and bring it even with the slab.

Filling the Channel with Sand

Several more passes of Emecole 555 were applied to the top coat of sand. It was better to make several light passes so the Emecole could soak into the sand, rather than a single heavy pass that would largely run off.

Finish Coat of Emecole 555

The crack was beveled off and tailored with a putty knife. The Emecole and sand forms a grout like mixture that was smoothed down for an even transition between the uneven slabs. Excess grout is tossed in the plastic jar. I packed some of the wet grout into the vertical crack along the edge of patio slab (see the first photo on this page).

Smoothing the Emecole 555 Sanded Grout Mixture

A light dusting of sand is spread over the curing Emecole 555 after scraping up the excess with the putty knife.

Light Dusting of Sand

I used the entire cartridge of Emecole 555 to fill this wide and deep crack.

Concrete Slab Crack Repaired with Emecole 555 Fast polyurea

Emecole 555 Finish Grinding

The outside temperature was 48 degrees and dry on this early November afternoon. The Emecole 555 gelled within a few minutes, but took longer to fully cure and harden as judged by the Emecole sand/grout I saved in the plastic jar. With the temperature dropping to the high 20′s overnight, I left the Emecole to harden overnight.

The next morning, I swept off the loose sand and finish grinded the cured Emecole 555 with the angle grinder and masonry wheel.

Finish Grinding the Emecole 555 Concrete Slab Repair

The results were amazing! The Emecole was rock-hard, felt like concrete, ground to feather edge and turned to a concrete gray color.

Cracked Concrete Slab Repair with Emecole 555 Fast polyurea

The buffed Emecole is paintable and will blend with the rest of the slab when I restain the patio.

Application Tip

If I were to do this again – I would prime the beveled edges of the crack that I had ground on the concrete slab with some Emecole 555 squirted into a cup and painted on with a disposable foam brush. The primed concrete edges would have sealed more easily as I smoothed down the Emecole / sand grout mixture. As it were, I needed to make sure the grout was sufficiently moist to wet the beveled edge of the concrete. It’s really more of a cosmetic improvement if you need to fix a highly uneven crack such as this.

Hope this helps,

Bob Jackson

Copyright © 2013 HandymanHowTo.com   Reproduction strictly prohibited.

The post Concrete Slab Crack Repair – Part 2 appeared first on HandymanHowto.com.

This project explains how to repair a large wide crack in my patio concrete slab with Emecole 555 Fast polyurea resin. The concrete slab cracked, slid downhill by 1/2″ and tilted up about 3/4″ as shown due to soil settling and the weight of the poured concrete steps on this 5 foot wide section of patio. I felt that surface patching would be insufficient and chose the Emecole 555 polyurea to create a structural repair that would bond the concrete slabs together to the full depth of the crack.

Large Crack in Concrete Patio Slab

Concrete Repair Options

The following table summarizes several QUIKRETE® concrete repair products that are widely available at home improvement stores with the Emecole 555 Fast polyurea resin system. Given the 6″ to 10″ deep by 1/2″ to 3/4″ wide crack in my concrete patio slab, the two choices for this job were the QUIKCRETE Vinyl Concrete Patcher No. 1133 and Emecole 555 Fast.

Concrete Slab Crack Repair – Emecole 555 Product Comparison Table

I decided against concrete for the following reasons:

• Concrete is relatively weak in tension (pull apart) strength and couldn’t prevent the slab from shifting again.
• It would be difficult to work concrete to the full depth of the crack, resulting in air pockets and voids.
• I had doubts the “cold joint” between the new concrete filler and the slab wouldn’t crack again.

I happened upon the Emecole 555 product after an extensive on-line study of concrete slab crack repair products and techniques. I felt comfortable choosing Emecole after reading their extensive online literature (the video is really helpful) and called Emecole to verify it was suitable for my particular problem.

Emecole 555 Fast polyurea resin appeared to be ideal because:

• It is very strong in tension strength. At over 4000 PSI, Emecole is stronger than concrete.
• It is a thin liquid that penetrates deeply into the crack, filling all voids.
• It soaks into the concrete to form a high strength chemical bond.
• The sanded and cured material is similar to concrete in texture and color.

The main downside to Emecole 555 is it’s expensive at $155.95 for the DIY Starter Kit. If you already have the “Jake” tool dual-cartridge dispensing gun, the materials only Add-On Kit price is $128.95. I bought my Starter Kit from Best Materials.

Emecole 555 – Concrete Slab Repair Kit

Emecole 555 has a shelf-life of 1 year. If you follow the dispensing instructions to avoid cross contamination, a cartridge pack can be partially used, capped off and saved for later.

Concrete Slab Crack Repair

End of the patio had lifted about 3/4″ when it cracked and shifted downhill from the main slab. The raised lip created a trip and fall hazard, so I needed to bevel it to make a smoother “ramp” transition.

Raised Crack in Concrete Slab

I began chipping the high side of the cracked slab with a brick chisel and 3lb sledge hammer. This worked really well and went quickly.

Chipping the Concrete Crack with a Brick Chisel and Hammer

After some rough shaping with the brick chisel and cleanup with a shop vac, I ground the high side of the crack smooth with my 4.5″ Dewalt Angle Grinder fitted with a masonry wheel. I was very pleased at how quickly the angle grinder knocked down the concrete lip. I’m maybe 10 minutes now into the job, things usually take longer than this. Dust wasn’t bad and a light breeze keep the air fresh.

Grinding the Concrete Crack with an Angle Grinder and Masonry Disc

Fill the Crack with Sand

The repair technique for a large deep crack differs a bit here from a more typical narrow crack. If I were to squirt the Emecole 555 into the crack to prime the concrete slab, it’d be like trying to prime the Grand Canyon; the Emecole 555 would just run out the bottom instead of pooling in the crack.

For large cracks such as this, the Emecole representative said to partially fill the crack with sand, then apply the Emecole 555. The Emecole 555 will then saturate the sand and slab instead of out the bottom of the crack.

I poured 14 cups of sand in the crack to bring to within 1″ of the slab surface!

Filling the Crack with Sand

After filling the crack to about 1″ of the slab surface, I ran the shop vac along the crack to pull out the high spots and level the sand. This created a 1″ to 1-1/2″ deep channel (important!) to hold the Emecole 555 in the crack so it can soak into the sand and bond the crack.

Sanded Concrete Slab Crack Ready for Emecole 555

Fill the Crack with Emecole 555 Fast

Emecole 555 begins to gel in about 3 minutes after it’s applied, so you need to plan your work and have your tools ready:

• Bag of sand
• Cups filled with sand
• 3″ inch putty knife
• Waste can for excess Emecole scraped up with the putty knife

The Emecole 555 was simple to apply as I filled the channel. Emecole has low viscosity (i.e. runs like water) and soaked right into the sand. I made several passes with the dispensing gun, refilling the crack.

Filling the Concrete Slab Crack with Emecole 555

This project is continued in Part 2.

Take care,

Bob Jackson

Copyright © 2013 HandymanHowTo.com   Reproduction strictly prohibited.

The post Concrete Slab Crack Repair – Part 1 appeared first on HandymanHowto.com.

This project is continued from Part 1.

After applying a bead of the QUIKRETE® Concrete Repair (No. 8620-10) sanded caulk, work it into the crack with a fingertip to seal it against the concrete.

Smooth the QUIKRETE 8620 Caulk into the Concrete Crack

Finishing the Caulk Line

The caulk line now has a U-shaped depression from your fingertip that must be filled to prevent water from pooling in the crack and to present a even surface for a nice looking appearance.

1. Apply a 2nd thin layer of caulk along the crack.
2. Pull a putty knife along the crack to smooth the caulk.
3. Push the putty knife over crack to scrape away the excess caulk.

Scrape Off the Excess Concrete Caulk with a Putty Knife

The crack narrowed as it approached the house. No backer rod is needed when the crack narrowed to less than 1/4″. The crack is fully caulked and finished in this photo.

QUIKRETE 8620 Caulk, Backer Rod and Tools for Cracked Concrete Repair

The crack will be stained to blend with the rest of the patio concrete after it cures.

Patio Slab Edge Repair

The crack in the outside edge of the patio slab is patched using the same method with backer rod to fill the crack and QUIKRETE 8620 caulk.

The foam backer rod is pressed into the surface of the crack:

Cracked Concrete Patio Slab – Corner Repair

The backer rod is seated with a screw driver:

Backer Rod Filler Seated in the Cracked Concrete Slab

The crack is caulked and smoothed with a fingertip:

Concrete Crack Filled with QUIKRETE 8620 Caulk

A second thin bead of caulk is applied, then smoothed and scraped with a putty knife.

Finished Crack in the Patio Concrete Slab

Results

The QUIKRETE Concrete Repair No. 8620 caulk did a good job at an unbeatable price. Easy to apply with simple tools and has the sanded texture of concrete. I needed only one 10oz tube to patch the 13 foot long crack. The patch will not be noticeable when I apply a new coat of concrete stain.

My patio slab cracked because the soil foundation settled. I believe the soil and slab movement has stopped as the house is 10 years old. Caulk is best suited for stable slabs and cracks where a weather-seal will suffice. I’m curious to see how well the caulk will hold up over time and if peeling will be an issue.

Concrete Patio Large Crack Repair

The other end of my concrete patio slab has a large 1/2″ crack where the poured concrete steps have pulled away. Caulk and concrete would be insufficient because a high strength structural bond is needed glue the slab back together to prevent further movement. I plan to use the Emecole 555 polyurea DIY Slab Repair Kit to mend the slab.

Emecole 555 polyurea Concrete Slab Repair Kit

Look for the Emecole 555 project slab repair write-up very soon!

Take care,

Bob Jackson

Copyright © 2013 HandymanHowTo.com   Reproduction strictly prohibited.

The post How to Repair a Cracked Concrete Patio – Part 2 appeared first on HandymanHowto.com.

This project explains how to patch a cracked concrete patio. My concrete patio slab developed a 13 foot long crack that varied from a hairline next to the house, widening to 3/8 inch at the edge of the patio. I wanted to repair the crack before winter prevent water from freezing in the crack, causing it to get worse.

Cracked Concrete Patio Slab

Freezing water expands with tremendous force that will widen a crack by shifting the concrete slab and/or creating new cracks to relieve the stress. Repeated freeze/thaw cycles can do a lot of damage to concrete.

Cracked Concrete Patio Slab

Concrete Slab Crack Repair Options

There are many products and methods to go about patching or repairing a cracked concrete patio slab. The main options are:

• Caulks & Sealers – inexpensive, easy, non-structural (i.e. has no strength), surface patch of uncertain long-term durability. Only for cracks less than 1/2″ wide.
• Concrete – inexpensive, semi-structural, repair to full depth of the crack. Best for cracks 1/2″ or wider due to difficulty of forcing concrete into a narrow crack all the way down in a 6 inch thick concrete slab. For best results, the crack should be undercut with a chisel to form an inverted V notch for maximum holding power at the “cold” joint between new and old concrete. Concrete is relatively weak in tension and can’t prevent slab movement if the foundation is less than 100% stable.
• Polymer Resins – expensive, deep penetrating, structural repair which forms a permanent chemical bond with the concrete slab, gluing the slabs together. Compressive- and tension (i.e. “pull apart”) strength of 4,000+ psi exceeds that of concrete to prevent the slab from moving. Slightly less rigid than concrete for stress relief. Epoxy and Polyurea adhesives are example materials.

This table summarizes several QUIKRETE® concrete slab crack repair products that are readily available at home improvement stores and the Emecole® 555 polyurea adhesive resin. Click on the table for a full size view.

Concrete Slab Crack Repair – Product Comparison Table

For this repair, I chose the QUIKRETE® Concrete Repair (No. 8620-10) sanded acrylic latex caulk for the following reasons:

• It is designed for concrete crack repair.
• Sanded formula to resemble concrete.
• The slab crack was less than 1/2″ wide.

I decided against the following products for this application because:

• QUIKRETE® Polyurethane Self-Leveling Sealant (No. 8660) has a smooth texture and the self-leveling properties wouldn’t do well on the edge of the patio.
• QUIKRETE® Gray Concrete Crack Seal (No. 8640) also has a smooth texture, cures/dries relatively slowly and I was concerned about run-out at the edge of the patio. It’s recommended the concrete should be chemically cleaned for a good bond.
• QUIKRETE® Vinyl Concrete Patcher (No. 1133) looked to be an excellent choice for this job, but I thought the crack was too narrow in areas for concrete to work well.
• Emecole 555 is very impressive, but I thought I’d try a less expensive product first.

QUIKRETE® Concrete Repair Caulk

I purchased a QUIKRETE® Concrete Repair (No. 8620-10) 10oz caulk tube for $3.68 and a bag of 3/8″ x 20′ closed cell polyethylene backer rod for $2.79, for a total cost of $6.47 plus tax in materials. The backer rod is a filler for cracks 1/4″ or wider.

QUIKRETE® Concrete Repair (No. 8620-10) and Backer Rod

The QUIKRETE 8620 caulk is suitable for cracks 1/8″ to 1/2″ wide. The caulk should be applied no more than about 3/8″ thick, using backer rod or sand to fill deep cracks.

The maximum crack width on my patio was about 3/8″ wide to the full 6″ or 8″ depth of the slab.

3/8″ Wide Crack in Concrete Patio Slab

I hope the builder installed wire reinforcing mesh when the concrete slab was poured, but I couldn’t see well enough into the crack to confirm. If wire mesh is in there, it has broken as the slab cracked in two.

Backer Rod Installation and Caulking

The foam backer rod is pressed into the wide sections of the crack to serve as a filler before caulking. Press the backer rod into the crack with your fingers.

Concrete Patio Crack Repair – Backer Rod Installation

Then seat the backer rod about 3/8″ deep with a screw driver.

Seating the Backer Rod in the Concrete Crack

Fill the crack with the QUIKRETE 8620 caulk. Note the gray color of the concrete in contrast to the white concrete stain on my patio. The QUIKRETE 8620 caulk is paintable and will be covered when I stain the deck.

QUIKRETE Concrete Repair No. 8620 Sanded Caulk

This project is continued in Part 2.

Thanks for reading,

Bob Jackson

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The post How to Repair a Cracked Concrete Patio – Part 1 appeared first on HandymanHowto.com.

This project shows how to build a cement entrance ramp over concrete steps for easy access to the basement storage area.

The basement double-doors opened to a large unfinished room that would be perfect for storing the riding lawnmower and utility cart. Problem was, the room couldn’t be accessed by wheeled vehicles because of a concrete step. The solution: build a cement entrance ramp!

The finished cement entrance ramp:

Cement Basement Door Ramp

How to Build a Cement Entrance Ramp

I used the following materials and tools to build the cement entrance ramp over the concrete steps:

• One to two dozen 60 lb bags of Quikcrete cement. More on estimating follows below.
• Concrete trowel
• 5 or 6 foot length 2×4 lumber
• Shovel
• Pencil
• 6 foot section of ~1 inch diameter flexible PVC conduit with press-open seam
• Portable electric cement mixer – rented from Home Depot or Lowes
• Benjamin Moore Acrylic Latex Concrete Stain 072.

Portable Electric Cement Mixer

Cement Mix Materials Estimate

Decide where the ramp will begin. Lay a long board down to determine the slope of the ramp. The ramp should not be short and steep or your equipment will get ‘high centered’, that is, the riding mower / golf cart / wagon / etc. will get stuck at the top of the ramp on the threshold with the front wheels in the air. Mark a line where the ramp will begin on the concrete slab.

Example dimensions of the ramp and stair

Use this formula for the  volume of a wedge:

Volume_Wedge = 1/2 * width of ramp * height of ramp * length of ramp

In this example,

Volume_Wedge = 1/2 * 72 * 14 * 72 = 36,288 in³

Next, measure the width, height and length of the existing concrete step in inches. In my case there as only one step. The volume of a step is:

Volume_Step = width * length * height = 12 * 72 * 7 = 6,048 in³

The volume of material needed for the ramp is:

Volume_Ramp = Volume_Wedge – Volume_Step = 36,288 – 6,048 = 30,240 in³

Divide the ramp volume calculated in cubic inches by 1728 to convert cubic inches to cubic feet.

Volume_Ramp ft³ = 30,240 in³ / (1728 in³ / ft³) = 17.5 ft³

A 60 lb bag of cement equals 0.45 cubic feet (ft³). To figure the number of bags, use the formula:

# of 60 lb bags of cement = Volume_Ramp ft³ / 0.45 ft³ = 17.5 ft³ / 0.45 ft³ = 39 bags (rounded up)

For my particular job in the above photo, I used about 26 bags of Quikcrete cement.

Concrete Surface Preparation

The existing concrete slab and stair step must be clean and dry. If the stair is painted, look closely to determine if has a  roughened “broom finish” – as shown in my photos here. You can pour the ramp over a rough broom finish slab and it will not move – move on to “Mixing and Pouring”.

If the existing concrete step is smooth and/or covered with an enamel paint, you should chemically stripping the old paint or try sandblasting to reveal bare concrete. If stripping is not feasible, drill holes and and hammer in couple of short lengths of rebar in to the existing slab and stair step. Keep the rebar short and well beneath the surface of the ramp. Six inches deep and 2 inches above the existing concrete surface will be sufficient.

Cement Entrance Ramp Mixing and Pouring

No forms are needed to build the ramp. The concrete is stiff enough to hold the ramp shape.

1. Install the flexible PVC conduit around any existing phone or TV cables. In my case, I had phone and DirecTV lines running underneath the threshold lip. In the future, I might need to repair or run new cables and didn’t want these embedded in concrete. See the closeup photo below.
2. Mix two bags of Quikcrete according to the instructions on the bag in the electric mixer. You do not want to mix this amount of concrete by hand! Keep the mixture a bit on the stiff side.
3. Starting at the center of the step, pour the cement onto the step. Notice the cement mix can be maneuvered and and tipped like a wheel barrow. Keep the drum turning while pouring or the cement will tend to stick inside the drum.
4. Use the shovel to knock down high spots and distribute the concrete into the corners.
5. Continue mixing and pouring, working from the door center to the sides.
6. As you near the final dimensions of the ramp, work the 2×4 across the ramp face from top to bottom to produce an even slope.  That is, one end of the of 2×4 will be laying on the door threshold and the other end will be on the line you marked earlier for the bottom of the ramp. Use the concrete trowel toss cement into low spots.
7. Contour and float out the ramp face and sides using the concrete trowel.
8. Drag a broom across the face of the concrete to roughen of the surface slightly for traction. This is called a ‘broom finish’.
9. Keep the concrete damp and allow to cure according to the instructions on the bag for that mix and outside temperature.

This is a closeup of the flexible PVC conduit that was applied around the existing TV and phone cables. This allows for easy maintenance and repair in the future.

Conduit in Cement for Cable TV and Phone Lines

After the concrete had cured for 30 days, I rolled on a coat of Benjamin Moore Acrylic Latex Concrete Stain 072. I’ve had great results with this over the years, with no evidence of peeling.

Hope you found this project helpful!

Bob Jackson

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The post How to Build a Cement Entrance Ramp appeared first on HandymanHowto.com.