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Concrete Expansion Joints: Keep them Watertight and Crack Resistant

Concrete Expansion Joints

Concrete expansion joints are important for your sidewalk or driveway.

Keeping your joints watertight will prevent moisture from seeping under concrete pads and causing them to heave or sink. This post shares how to accomplish this task.

The purpose of a concrete expansion joint is to allow the pads to expand and contract (get bigger and smaller) with temperature & humidity changes.

If you’ve got kids think of the expansion joint as yourself and the concrete pads as your children- queue memory of standing between two kids as they try to tear each other apart. Well, this is how I feel sometimes with my daughters (is it bad if I view myself as an expansion joint that buffers arguments about clothes, food, and hair?).

Good news!!

Protecting and repairing a concrete expansion joint is super easy. And it’s far cheaper to do this weekend project than it is to hire a contractor to replace a severely damaged concrete driveway or sidewalk.

Here are the supplies you’ll need

  • Sikaflex self-leveling sealant
  • Caulking gun
  • Utility knife
  • Acetone
  • Rags (you’ll need several)
  • Safety glasses
  • Rubber gloves
  • Angle Grinder (possibly but not always necessary)
  • Angle Grinder cutting wheel

This supply list may sound intimidating because of the angle grinder.

But what better time to begin using one of these awesome tools, and they can be very affordable.

So let’s get started and seal your concrete expansion joint so it’s protected from the effects of weather!

Removing Old Material from a Concrete Expansion Joint 

Concrete expansion joints are also known as isolation joints.

Like I said in the intro these joints allow concrete pads to expand and contract during freeze-thaw cycles.

Without a concrete expansion joint your sidewalk or driveway would crack.

If you look at the expansion joints between your concrete you might see black felt or old sealant.

Old sealant and worn out felt needs to be removed.

 

Concrete Expansion Joints-Remove old sealant

 

When I called Sika, the company that makes the self-leveling sealant for this kind of project, they told me to use a utility knife to remove old material and clean off any remaining residue with acetone. If you do this step, make sure the Acetone flash dries (Sika said to wait about 1 hour).

You could give this utility knife technique a try. But I found that the people who owned our house applied a layer of new sealant over an old layer. And I had a true hot mess because both sealants were pulling away from the concrete.

If you’re in the same predicament, using an angle grinder with a standard cutting wheel is the way to go.

Sure, neighbors might think you’re a bit crazy. But they also will think twice about sending their kids over for fundraisers (which could be a good thing if they’re selling wrapping paper or other stuff, bad if they’re offering Girl Scout cookies).

 

Concrete Expansion Joints-Angle grinders help remove old sealant

 

Yes, the angle grinder is an extra purchase but you can get one cheaper than a pair of running shoes.

And if you’re only going to use the grinder for one project you could resell it on Craigslist (in case you haven’t heard of Craigslist check it out here www.craigslist.org).

In my example I had to cut through two layers of old sealant. The angle grinder cutting wheel had to penetrate about 1/2 to 1 inch down through the sealant layers. You should also remove any old foam backer rod that is beneath the sealant (I’ll explain what this is in the next section).

The concrete joint doesn’t have to be perfectly clean for the new sealant. And old sealant that’s left behind after you use the angle grinder will be pretty well adhered to the concrete and won’t interfere with the new sealant’s bonding capacity.

Loose sealant on the edge of the expansion joint can be scraped off with your utility knife.

This step is perhaps the most important one. It’s definitely the most time-consuming.

Make sure you wear safety glasses and protective gloves since the cutting wheel sparks a bit when it occasionally touches the concrete.

Here’s a short video to give you an idea of what needs to be done to remove old sealant from a concrete expansion joint.

 

Concrete Expansion Joints Part 1-Remove Old Sealant
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Prepping Your Concrete Expansion Joint for Sealant

If you’re as nerdy as me when it comes to remodeling you may have wondered what the heck that rubber stuff is between concrete pads or walkways.

It’s okay if you’ve never had this thought, this means you’re normal and the rest of us DIYers are at risk of tripping over ourselves while pondering such questions.

The stuff that looks like rubber is a self-leveling sealant. The brand you can find at the local store here in the states is called Sikaflex Self-Leveling Sealant (here’s a link to the product description on Sika’s website http://usa.sika.com/en/solutions_products/02/02a024/02a024sa008.html)

Sikaflex can be used to seal horizontal expansion joints. It’s a great product because it remains permanently flexible, dries quickly, sticks to anything, is self-leveling, and highly resistant to weather conditions.

 

Concrete Expansion Joints-Sikaflex is self leveling sealant

 

You should apply Sikaflex when the temperature is between 40F-100F. The ideal temperature is in the middle of this range because the joint will be less likely to be fully contracted or expanded.

Sikaflex will be tack free in 1 to 2 hours and fully cured in 3 to 5 days.

I didn’t drive on it for 5 days. Who wants tires tracks of sealant on their driveway (not me and I certainly don’t want to explain this to my wife). Also, make sure rain isn’t in the forecast for 24 hours.

After removing all the old sealant use a vacuum or wet/dry vac to suck up any debris from your concrete joints.

Then use a closed cell foam backer rod in between the joints.

 

Concrete Expansion Joints-Backer rod needs to be placed in joints before sealant

 

Foam backer rods act to fill in space between concrete joints so you don’t need to use a ton of self-leveling sealant.

Here’s a BIG TIP: the diameter of the backer rod should be 1/8 inch larger than the width of your concrete expansion joint.

This will ensure a water tight seal.

 

Concrete Expansion Joints-Add closed cell backer rods to joints before sealant

 

Push the backer rod down into the joint with your hand. The depth of the joint should be a minimum of 1/4 inch and a maximum of 1/2 inch below the concrete pads. This means the backer rod should be this far below the concrete pad surface.

If your joint is wider than the backer rod you can twist two stands together like rope.

Here’s a Second BIG TIP: double-check the backer rod sits beneath the surface of the concrete pad.

Otherwise you’ll have a little hump that develops when you apply the sealant. And yes, I’m speaking from experience :(

By the way, the backer rod can be found in the same section as the concrete supplies at the hardware store.

 

Keep Your Concrete Expansion Joint Watertight and Crack Resistant with Sikaflex Sealant

Gather all your old socks and a few worn out T-shirts.

You’ll need them as rags (don’t whine about using your old Pink Floyd concert shirt, nobody thinks you’re cool if you wear it to the mall in 2000 whatever. Hey, I love Pink Floyd but seriously, if you’re reading this you’re probably old enough to know they aren’t touring anytime soon).

Sikaflex self-leveling sealant comes in two size tubes. The large tube is 29 fluid ounces and the small tube is 10 fluid ounces.

If you have a huge concrete expansion joint to fill I highly recommend the 29 fl oz tube. You’ll have to buy a large caulking gun but this will save you a ton of time.

 

Concrete Expansion Joints-29 oz tubes of Sikaflex require a large caulking gun

 

Here’s a Third BIG TIP: Think about how many tubes you need then BUY twice as many.

Again, talking from experience here. It’s so much easier to buy a ton of sealant then return what you don’t use.

With the backer rod in place you can cut the Sikaflex tube so that it will make a 1/4 inch bead. You might be tempted to cut the tube bigger but don’t.

Once the sealant starts flowing it can be hard to stop and a bigger bead means you’ll have to work faster. Not to mention, but I will anyway, the huge potential mess you might have. Visualize sealant on your pants, hands, shoes, hair…..

Pierce the seal inside the tube with an old wire hanger, the kind you get from the dry cleaners.

Place the tube in your caulking gun and pretend you’re Dirty Harry. Just kidding. This step is unnecessary and only meant to make you feel cool (which you are of course).

Squeeze the Sikaflex sealant into the concrete expansion joint and allow it to flow & self-level itself. Add more Sikaflex where it’s needed.

Voila!!!

Your concrete expansion joint is now watertight and way more unlikely to crack.

In case you’re more into watching than reading here’s a video showing you what to expect when using Sikaflex

 

Concrete Expansion Joints Part 2-Apply New Watertight Sealant
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Sikaflex is like Vitamin C for expansion joints. The watertight seal will protect the joint from inclement weather and add longevity to your concrete driveway or sidewalk.

I hope this post helped you.  Always feel free to ask a question or add your own comment below.

Do you like keeping your house updated? Follow me on Facebook because I like to upload different weekend projects you can do that add value and safety to your house (I’ll make it easy by providing this link www.facebook.com/homerepairtutor).

Until next time, make it a great day!

Jeff Patterson

 

 

 

 

P.S. Never miss any of my tips, sign up for my email newsletter.

My emails are short and sweet like my Italian mom (she’s only 5 foot tall but don’t tell her I said this).

P.P.S. Since a lot of people have questions about concrete expansion joints that meet up with different materials like brick or asphalt I wanted to recommend Sikaflex Concrete Fix. This hyperlink is a PDF of the product sheet. You should check it out if you have an expansion joint butts up against brink or asphalt. Maybe this product for you and maybe it’s not, but I wanted to offer it up as a suggestion.

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94 comments… add one

  • Jeanne K. Briscoe March 10, 2013, 12:05 PM

    You have so many good tips. I need the joints redone in my driveway as well as a long walkway and patio made of flagstone. Do I need a concrete company for this or who? Athens, Ga.

    • Jeff Patterson March 10, 2013, 10:25 PM

      Hi Jeanne, you could hire a mason, contractor with concrete experience or do it yourself :)

      It’s really not that hard to do. Certainly there is a time element because the old sealant or felt needs to be removed if worn out. But the application of the new sealant is as easy as caulking.

  • Jennifer @ Decorated Chaos March 11, 2013, 12:18 AM

    Awesome post/tutorial. My house is 65+ years old and in need of of this!

    Thanks for sharing! (I just pinned to my DIY Pinterest board)

    Jennifer

    • Jeff Patterson March 11, 2013, 5:41 AM

      Thanks Jennifer, glad it was helpful and I appreciate your pin because that helps others see this project is pretty easy.

      You and I are in the same boat (caring for an older home) and sometimes it springs a leak or two or three!! LOL.

      Hope you have a great day :)

  • Pam Oleson March 11, 2013, 1:20 PM

    When our concrete steps were poured a few years ago, the contractor did not put an expandable joint between the bottom step and the concrete sidewalk slab. Can I use the grinder to create a joint and follow these directions. There is a crack between the step and slab.
    thanks.

    • Jeff Patterson March 11, 2013, 1:49 PM

      Hi Pam, you could try to do that but it’s a lot of work. The best option would be to use a crack filler to seal the crack.

      This will stop water or ice from penetrating the concrete. Here’s a tip, measure the width of the crack and find a concrete crack filler that can accommodate that dimension.

      For example, if the widest point in your crack is 1/4 inch wide then use a filler that states it can fill a 1/4 inch or larger crack.

      Hope this helps :)

      • Pam Oleson March 11, 2013, 3:22 PM

        Thanks. I’ll give it a try when it warms up (I live in MN).

  • Ryan March 21, 2013, 11:44 AM

    Wow this really great Jeff. I have been looking on the web for an easy to follow guide on properly fixing concrete joints. I have a weed problem as well and have been removing them from the cracks which leaves a little gap. Also I’m sure most people know this but going to Home Depot and renting tools is also a good way to keep the cost down if you are only going to use the tool once.

    Thanks for providing this. I’m definitely going to check out your other guides!

    • Jeff Patterson March 21, 2013, 11:47 AM

      Thanks Ryan for the reminder about renting tools. Another option is to look for refurbished items on Amazon.

      I picked up a great tile saw this way.

      You can also get good tool deals on Craigslist!!

      Glad the post helped you out. Hope you’re having a fantastic day :)

  • Ryan March 21, 2013, 11:50 AM

    Wow this is really great Jeff. I have been looking on the web for an easy to follow guide on properly fixing concrete joints. I have a weed problem as well and have been removing them from the cracks which leaves a little gap. Also I’m sure most people know this but going to Home Depot and renting tools is also a good way to keep the cost down if you are only going to use the tool once.

    Thanks for providing this. I’m definitely going to check out your other guides!

    • Jeff Patterson March 21, 2013, 12:00 PM

      Thanks Ryan for the reminder about renting tools. Another option is to look for refurbished items on Amazon.

      I picked up a great tile saw this way.

      You can also get good tool deals on Craigslist!!

      Glad the post helped you out. Hope you’re having a fantastic day :)

  • Jackie May 27, 2013, 4:06 PM

    Thanks for this post!

    I went to Sika’s website and see MANY self-leveling sealants…..which one should I get for the concrete joints?

  • Geneva June 16, 2013, 11:47 PM

    My sidewalks and driveway here in Houston has a piece f wood as an expansion “joint”. These are getting old and the wood is decaying. Do I just pull it out and use this sealant? Wonder why they used wood?

    • Jeff Patterson June 24, 2013, 2:35 PM

      Geneva, the wood acts as an expansion and contraction joint. It helps prevent the concrete from cracking. You could remove the wood and replace it with a similar type if wood or use foam backer rod along with Sikaflex.

      Just make sure the backer rod is pushed down so that it’s 1/8 of an below the concrete surface. Then apply Sikafkex according to the instructions.

      • Geneva June 24, 2013, 3:33 PM

        Thank you! I do have cracks, and actually, all the driveways in my neighborhood are sinking slowly (no rebar used by home builder), I’ve already poured a new proper 1/2 portion of it because my sink level had dropped so much. Really pathetic. I’m going to follow your guide and replace the wood. I’m also going to look for a good sealant/concrete repair material to try and stop the long linear cracks I see as well. Thank you!

        Geneva

        • Jeff Patterson June 25, 2013, 5:22 AM

          Geneva, if you learn a new skill while replacing the wood please let me know!! I love discovering new ideas and adding to my tool box of knowledge :)

  • Ed July 13, 2013, 5:10 PM

    Great video Jeff! Thanks for all the great advice.
    I’m also wondering about the control joints located between pads (those grooves that “encourage” cracks to occur there vs. in the pad themselves). Is it advisable to seal these as well, and to use backer rod + sealant to fill up the groove such that it is level with the remaining pad?
    Or is it better just to seal the actual crack itself and leave the groove profile intact?
    Thanks!

    • Jeff Patterson July 13, 2013, 8:45 PM

      Great question Ed. Honestly, I’m not sure what to do with concrete control joints. One thing’s for sure, I wouldn’t backfill them with backer rod. Just leave them the way they are. But what should be done with a crack that gets wider within the control joint itself? If it were me, I’d fill in the crack just enough to seal it (with something like SikaFlex which can be bough at home stores). But I wouldn’t fill up the control joint. Let me know if you feel like this isn’t a great answer. Isolation joints and control joints are a bit different in their makeup. And as such, need to be treated differently too.

      :)

      Jeff

      • Daryl Gilbert November 1, 2013, 12:02 AM

        Jeff,
        My daughter’s home in North Carolina is three years old. The home is on a hill so the driveway has a decline down to the street. There are channels (maybe called sore joints, definitely not expansion joints) that have cracks in them (both directions, up/down and across). When it rains, sand rises up through the cracks and settles at the bottom of the driveway. The builder has filled the cracks twice with a caulk type product. One month after each application of caulk, the caulk cracks then allows sand to escape again. Any suggestions?

        • Jeff Patterson November 2, 2013, 7:37 AM

          Hi Daryl, do you know if the builder used a product like SikaFlex? Not all joint fillers are made the same and I like this product because of its elasticity and ability to flex with the concrete. That said, you’d have to remove all the old filler to ensure the SikaFlex would stick to the joints. Just make sure that your joints can accept SikaFlex Self-Leveling sealant based on the directions. Here’s the link to the site

          http://usa.sika.com/en/solutions_products/02/02a024/02a024sa008.html

          Hope this helps a bit.

  • Geneva July 15, 2013, 10:34 PM

    Jeff,

    Was in my local Ace hardware store and they had cut to whatever length you need rubber expansion joint tubing that you press down and tightly fit in the space. Have you heard of this?

    I have a picture of it if you are interested.

    Geneva

    • Jeff Patterson July 20, 2013, 5:45 AM

      Hi Geneva,

      I’ve never heard of this option but that’s pretty cool. Maybe is a local thing. However, if it’s not this would be wonderful to let people know about since sometimes you only need a few feet. Totally send me a picture. My email address is jeff@homerepairtutor.com.

      Jeff

  • David Kapral July 18, 2013, 11:48 AM

    Hi Jeff. this is a good DIY procedure! I am in the middle of doing this job on my driveway and can add a couple of things based on hard experience:

    1. the best reason for installing backer rod is so the self leveling sealant doesn’t ooze through the void. When it does, there will be bubbles that look like grey acne in the job and sections will sink and look quite ugly. This can lead to “3 point bonding” & a failed job.

    2. Dam up the ends if the joint is even slightly sloped. Self Leveling sealant will ooze out of either end. Tape will work as a dam on clean surfaces.

    3. Sealant Engineering Co. offers an adhesive backer rod (“Seafoam”) in various widths and thicknesses that works well in shallow joints. It helps prevent the backer rod from floating up, making unsightly humps. Sealant Engineering offers “Low Modulus” silicone products that are supposed to be free of the UV problems on polyurethane (hardening, cracking). I’ll be trying it.

    4. Sealant Eng also has 1/4″ triangular, adhesive backed backer rod for use at the driveway / foundation junction. This is supposed to give the joint flexibility if reg backer rod can’t be used. I will let you know.

    • Jeff Patterson July 20, 2013, 6:13 AM

      Hi David,

      Like I said in our emails you have a TON of fantastic tips. Please let me know how this project works out for you so that we can feature in on DIY Success Stories. Driveways and sidewalks can be super expensive to repair. And if these products can help us homeowners save money and time then they are well worth the money.

      :)

      Jeff

  • Dave Anderson August 10, 2013, 7:18 PM

    I just did my expansion joints with backer road and Sikaflex. Prep was the big job. Now I am looking at the “control joints” which of course have cracks in them. They look kind of dumb with the nice grey sikaflex expansion joints. So I was wondering about sweeping some loose sand into the cracks in the joints and adding sikafex without backer which would not work as the joints are not that wide or deep. Any thoughts? Sikaflex is too thin and would probably run thru the un-stoppered (sand filled) cracks.

    • Jeff Patterson August 11, 2013, 7:40 AM

      Hey Dave,

      I spoke with another friend about this exact issue. It’s good that there are cracks in the control joint because that indicates they’re doing their job (keeping the cracks confined to the joint and not the concrete pad). Prep indeed stinks for expansion joints.

      Does the sand fill in the small cracks within the control joint?

      This fix also is more aesthetic than anything. I’ve noticed several instances where control joints are simply left alone and the expansion joint is filled in with something like SikaFlex. It sounds like you’d prefer the joints to kind of “match” each other (I totally understand your preference because I’d probably want the same look). However, if the project is a pain in the butt then maybe living with the control joints the way they are isn’t too bad.

      Before you do anything give Sika’s technical service department a call and ask them for their opinion. They are AWESOME and won’t steer you wrong. Here’s the number 248-577-0020

      Ask them about your sand idea. I’d think that would work and you could always test it out on a small section of the control joint (like 12 inches). That way, if it didn’t work and the SikaFlex ran through you wouldn’t have to remove a ton of it. Hope this helps a bit.

      Jeff

      • Dave Anderson August 11, 2013, 9:06 AM

        Thanks for the reply. I understand about the purpose of control joints…to crack where you want it to! And it has. Not large cracks. I have one long center joint with the Sikaflex and two lateral ones (one at the garage and one on the pads (10). It looks really nice now. No caverns and no weeds! But like you said it is the aesthetics of those unfilled control joints that bother me. It would probably only take one or two big tube of Sikaflex to fill them as they are only 1/2-5/8″ deep “V” grooves cut with a tool when wet and having a smoothed border. You know the look. I was going to ask my neighbor about the idea of the control joints…he is the chief PA Dot bridge engineer for W. PA and he works with this sort of stuff on a big scale. He did his driveway 5 years ago and it appears he did the control joints too. I will call Sikaflex on Monday. I filled one with sane and swept most of it away. There is also a concrete crack filler at HD with a squeeze bottle that does fill cracks I think) but it may be too runny as well. I need 1/16 backer rod (LOL) so maybe I could use wet spaghetti! My daughter is an Architect and she specifies backer rod all the time but doesn’t ever recall 1/16. Thanks for writing back so quick. I’m waiting the 5 days now to drive over the joints. To help you visualize my driveway is 22 X 50″ Long, two lanes and 5 panels on each side.

        • Jeff Patterson August 12, 2013, 8:14 AM

          Hi Dave,

          Whew, your driveway is a big boy!! Let me know what you decide to do because I’d love to know. I think that you’ll end up with a great looking result that will last. Make sure to take several pics and send them to me, I should post your project so that other homeowners will know what to do with a similar scenario!!

          Jeff

  • Tim Lawrence August 14, 2013, 6:25 PM

    Jeff, I need to re-do my driveway expansion joints. However, my driveway has a decent slope to it. Just how “self levelling” is the Sika product? Will it simply run down the expansion joint to the street?

    • Jeff Patterson August 14, 2013, 9:40 PM

      Hey Tim,

      Thanks for your question, I got a similar one recently from another friend and have the same issue myself.

      Sika makes a product called Concrete Fix that doesn’t have the same sagging issues as their SikaFlex Self-Leveling product. Now, I haven’t used it yet and will probably call their tech line to make sure it’s okay. But the product details on their site say the Concrete Fix is meant for this kind of project. Hope this helps a bit. Let me know.

      Jeff

    • DaveAnderson August 14, 2013, 9:53 PM

      Sikaflex SL (self leveling) is like pancake batter. Apply a big bead between two slabs of concrete and you will have a nice flat shiny surface in a few minutes. You need to dam up the ends of the joint to contain the sealant. I think if you apply it at the top of a sloped driveway you will have a puddle at the bottom in no time. I think they make a thicker formula that might need tooled.

      • Jeff Patterson August 14, 2013, 10:01 PM

        Hey Dave,

        That thicker formula might just be Sika Concrete Fix. But like I said to Tim, I’d like to call Sika and ask them if it can be used for this specific purpose. Have you ever used it?

        Jeff

        • Tim Lawrence August 15, 2013, 1:25 PM

          Thanks for the replies gents. I guess the question for Sika is going to be along the lines of whether it is elastic enough?
          If there isn’t a product that will not work well on slopes, would my only option be the extruded ribbon type products like “Trim-a-Slab”

          Tim

          • Jeff Patterson August 15, 2013, 2:40 PM

            Hey Tim,

            I called Sika today and asked them about our sloped driveway issue. They said the Sika Concrete Fix would be a good option since it isn’t as elastic as SikaFlex Self-Leveling sealant and that it can be tooled with a plastic putty knife or spoon.

            So, this looks to be a viable course of action. Admittedly, I haven’t tried it yet but will. I’ll probably buy the smallest tube and give it a shot. Let me know if you try it :D

            Jeff

          • Tim Lawrence August 15, 2013, 3:13 PM

            Thanks for the update Jeff. I think I’ll have to go visit Lowes/HD and check it out.

  • kim August 23, 2013, 8:27 PM

    concrete pool patio – expansion joints. dirt and debris stuck in buff/off-white wet caulking. is there a way to remove it from the finished/hardened caulk or will it need to re-done?

    • Jeff Patterson August 25, 2013, 8:13 AM

      Hey Kim,

      Great question. Have you already tried to clean the caulk with soap and water? If so, I’d give Wet & Forget a try. It’s a surfactant that you spray onto outdoor surfaces. Water, wind, and sun activate it to clean over time (like 2-3 months). You may have to apply it a few times but I’ve had great success using it on patios & siding. Hope this helps.

      Jeff

  • Keith Himmel September 1, 2013, 4:17 PM

    Jeff,

    My story is a long one. I purchased my home in 1991. I have approx. 1400 sq ft of patio and a 24,000 gallon pool. We originally had Astro turf(yuk). We replaced it and the wooden expansion joints. The EJ’s were replaced with PVC and looked great at first but after a couple of years started to fail by sinking and holding dirt. My EJs go all the way down to the earth. Some are normal size some have grown wider and deeper. I thought about the SLAB GASKET material but there’s no “One size fits all”. SO I’m trying the SL QuikCrete product and it seems like I will probably need and 18 wheeler load. Are there larger diameter backer rod material? In my case it would bigger the better.

    Can you give a guy some direction?

    Thanks in advance,

    Keith Himmel

    • Jeff Patterson September 2, 2013, 10:09 PM

      Hey Keith,

      Thanks for your question. Sounds like you have an awesome outdoor setup.

      I believe you can get 3/4 inch wide backer rod. But if that’s too small the directions on the package say you can twist two pieces together to get a larger diameter. You could also call Quikrete’s tech support line. I’ve also had good luck with calling Sika for advice.

      Hope this helps a bit. Let me know.

      Jeff

  • Josh September 4, 2013, 1:02 PM

    Hey Jeff, Instead of using Foam backer rods could you use sand to fill up the hole? the gap between my garage and driveway is about 1/2″ wide so and its deep. (I have plenty of sand on hand if its OK to use.

    Thanks,
    Josh

    • Jeff Patterson September 8, 2013, 6:58 AM

      Hi Josh,

      You can get 3/4 inch foam backer rod and it should fit pretty tight in your gap. It’s not that expensive and will work better than sand. Hope this helps

      :)

      Jeff

  • Jesus September 13, 2013, 12:06 PM

    Hi Jeff,

    Great post!

    What if a day after using sikafelx SL I realize I need to apply another layer for a better leveling? Do I apply it right away (24 hours after first application) or do I wait 5 days until it cures?

    • Jeff Patterson September 14, 2013, 7:41 AM

      Hi Jesus,

      Good question. I don’t know the answer and would hate to steer you in the wrong direction. You should give Sika a call and ask their technical support department. Let me know what you find out because I’m curious myself.

      :)

      Jeff

      • Jesus September 14, 2013, 9:32 AM

        Just called them. They only work Monday through Friday. I want to get it done this weekend so I guess I’ll take my chances :-)

  • Steven John October 5, 2013, 12:42 PM

    I like your video representations for the SIKA concrete sealant but would prefer black. Do they have a choice for black or do you have any other product recommended with the black color?

    • Jeff Patterson October 5, 2013, 4:40 PM

      Hi Steven,

      I don’t know if Sika makes black. This would be a good option since the black would hide stains and whatnot. I’d have to do some research to see if black is offered in other brands. Let me know what you find if you get a solution first.

      Jeff

  • Toni October 15, 2013, 9:47 PM

    Hi Jeff,

    I have an expansion joint where my garage ends and driveway begins (and I can’t wait to follow your instructions to fix) and then I have another between the side of the driveway (concrete) and the RV pad (asphalt). Do I use the same material to seal the joints between these two different materials? I really want to do something because I currently have grass/weeds growing in the expansion joint. Toni

    • Jeff Patterson October 20, 2013, 5:55 AM

      Good questions, you may want to look into Sika’s Sikaflex Concrete Fix since you can use it with materials that have different coefficients of expansion. This might be a good option for your problems and I think you can buy it at either Lowe’s or Home Depot. I attached product info for this product in the P.S. in this post.

      Let me know what you think.

      Jeff

  • Tina November 10, 2013, 6:43 PM

    Very informative! The joint in my driveway varies and is over an inch. Is there width limit to this method? Also it has been pretty wide for quite a while. Is there a good way to remove the dirt and the weeds growing in there?

    • Jeff Patterson November 19, 2013, 5:32 AM

      Hi Tina,

      Our joints are over an inch as well. Make sure to read the label on the product that you decide to use. I do know that SikaFlex has specific instructions on depth and width.

      As far as the dirt & weeds, you could spray the weeds with a weed killer or vinegar first. Let them die off then remove them with a string trimmer. That’s probably the quickest way. Hope this helps.

  • wabi November 13, 2013, 10:44 PM

    First of all, I would like to thank you for posting this valuable resource. I’m a kind of person who wants to learn with any opportunity I have, and to learn especially on construction fields every single day.
    Thank you.
    Wabi.

  • Durai Thavamani November 17, 2013, 7:14 AM

    Dear Sir,
    I am in middle of resealing the concrete slab pavement. The damaged sealant were removed and I am stuck now due to rain and cannot pour the new sealant. Guide me of how to protect the existing joints from seepage of rain water that will harm the slab

    • Jeff Patterson November 17, 2013, 8:45 PM

      Hi Durai,

      I’m not sure what sealant you’re using. You’ll likely have to wait for the rain to stop before applying any product. You can always call the maker of the sealant and ask them for advice. I’m sure they’ll be helpful.

  • Bagya May 4, 2014, 9:22 AM

    can I apply sand over sikaflex so it blends with the existing driveway?

    • Jeff Patterson May 4, 2014, 7:12 PM

      Hi Bagya, wish I knew the answer to this but don’t. You should call Sika’s technical service line and as them their thoughts. They’re normally very nice and helpful.

      Please let me know what you find out since others might be thinking the same thing.

    • Tyler Sinclair May 26, 2014, 12:03 AM

      Good stuff, great blog, photos, video and all made it really easy to understand!

      • Jeff Patterson May 26, 2014, 7:21 AM

        Thanks Tyler. Hope it all helps you. Let me know if you have any questions.

  • Mike May 15, 2014, 9:32 AM

    Can I use sika concrete sealer at the base of my concrete foundation wall meets concrete sidewalk

    • Jeff Patterson May 18, 2014, 12:10 PM

      Hey Mike, great question. I’m not sure. You’d have to call Sika and explain your situation to them.

      Call the technical service line. They were pretty cool to me :)

  • Chris May 30, 2014, 11:56 AM

    Jeff, would it be better to leave the wood “expansion joints” in place of using the backer rods?
    Will the Sika sealant fill in the gaps around it?

    • Jeff Patterson May 31, 2014, 3:00 PM

      Sika will definitely fill any gaps Chris. Just make sure the wood is below the concrete.

      I’ve never tried this so it might be worth it to call Sika and get their opinion.

  • Thom Bouis June 18, 2014, 1:02 AM

    Trim-A- Slab is a better product, easier to install and longer lasting. Search Trim-A-Slab on eBay for best deal.

  • Kat June 18, 2014, 1:36 PM

    Hey Jeff! Great tutorial, big fan of DIY and just starting to get into house stuff and you are very thorough! Will definitely subscribe :)

    I have a sort of dumb rookie question that I seem to not be able to find on the Sika PDFs about the product (so I will apologize ahead of time) but what exactly is the dry time for Sika Cement Fix?

    We just used this to seal some cracks in the shower and some members of the family have been itching to shower now! It’s been about 28 hours now and I read somewhere that it needs 72 if we are planning to paint (we are not). Is that enough time?

    • Jeff Patterson June 19, 2014, 7:21 PM

      Thanks Kat, I love DIY too. You’ve got a buddy in me :)

      I’m not sure about the cure time for Sika Cement Fix. But call the Sika technical service line and see what they say.

      They’ve always been great at answering my questions. I’d hate to give you the wrong advice and ruin your DIY project.

      Let me know what they say.

  • Steve June 24, 2014, 8:12 PM

    To obtain a more textured and incognito appearance is it possible to sprinkle sand to the surface after caulking and if so how soon afterwards should this be done.

    • Jeff Patterson June 25, 2014, 5:39 AM

      I don’t see why you couldn’t Steve. I’d wait until the caulking is tacky so that the sand will stay on the surface.

      I’ve never done this before so keep me posted :)

  • Sherry June 28, 2014, 9:51 AM

    Hi Jeff,
    I’ve read about the width between the slabs, but I’m wondering about the depth? The depth seems very deep between the slabs on my driveway, I can can put my finger all the way down to the dirt. Is this normal? Also, any advice for directing the water away from the garage? The water pools at the entrance because of poor workmanship and it’s getting worse every year. I don’t have much to spend so any cheap ideas will help.

    • Jeff Patterson July 4, 2014, 6:47 AM

      You can use foam backer rod Sherry to fill the depth. I’d just get a backer rod that’s a bit wider than your gaps. That way you only have to place the backer rod so that it’s maybe 1/8 to 1/4 of an inch below your slabs. Then you can fill in the gap using Sika Flex self leveling sealant.

      I don’t know the answer to the pooling issue. You could put in a skirt drain that runs the length of the garage but that requires some work & money :(

      Maybe someone else has a better suggestion. Darn workmanship, it can be good or bad.

  • xaire July 4, 2014, 12:10 PM

    Jeff: Great information! You may want to add the information that if the backer rod is twisted to fill the joint the mastic is going to leak around the openings on the outside of the twists. Use a cheap caulking to prefill the openings, wait a few minutes for the caulking to set. I wasted about 3 tubes of mastic for first hand experience. Good ol’ hindsight.

    • Jeff Patterson July 4, 2014, 8:02 PM

      Thanks Xaire, that’s a great idea. I’m sure this will save us all a ton of money by using less self leveling sealant.

      You’re awesome!!

  • Brian July 7, 2014, 2:32 PM

    If this has been mentioned already, sorry, but would also have a bucket if fine sand and spread it over the caulking as you go, makes it look a ton nicer when finished. Sweep or blow the excess sand into the yard after 24 hours.

    • Jeff Patterson July 11, 2014, 7:21 AM

      Thanks Brian, that’s a great tip. I can already envision it looking a lot better :)

  • 127001er August 15, 2014, 9:26 AM

    Another tip: apply wide masking tape along either side of the crack or expansion joint, and at the ends of the work area. This will help to maintain a professional finish and assist with cleanup of any sealant that overflows during application.

  • John August 25, 2014, 9:13 PM

    I have a basement which is below ground level 1 metre, my concrete slab and the masonry walls are waterproof but the water is coming up between expansion joint which is between masonry wall and concrete slab is there a product that can stop a tiny puddle of water surfacing on my concrete slab when I get heavy rains?
    Kind regards John

    • Jeff Patterson October 14, 2014, 6:13 PM

      Hey John, sorry to hear about your water issues.

      This may sound obvious but are your downspouts clogged? If so, you may need to clean them out.

      Another issue might be your downspouts becoming disconnected from the underground drains.

      In which case you’d have to reattach them or just reroute the downspouts so that they drain 4-5 feet away from the foundation.

  • Mary August 27, 2014, 10:57 AM

    Love your advice and want to get started but used the level whereby some of the driveway concrete is higher than the garage slab and some spots are lower. Will this cause water to run into garage after I use the filler?

    • Jeff Patterson October 14, 2014, 6:08 PM

      It’s hard for me to say Mary.

      You could try to fill the expansion joint with the backer rod and then spray water on it with a hose. This might give you a good idea of how the water will travel before you fill the joint with the sealant.

  • Jim October 4, 2014, 10:32 AM

    Jeff,

    I can’t use Self Leveling sealant because the joint has a slight incline. What would you suggest for sealing inclined joints?

    • Jeff Patterson October 14, 2014, 6:04 PM

      Hey Jim, I have the same issue.

      And it’s not perfect but if you live in an area that gets cooler you could wait until the temperature drops enough whereby the sealant becomes less watery.

      I’m going to try this myself.

      You could also apply duck tape to either side of the joint so that any spillage won’t get on the cement.

      Maybe a call to Sika will reveal a product that’s better on inclines.

    • Joe October 29, 2014, 10:23 PM

      Sikaflex works on slightly inclined surfaces like my typical suburban tract home driveway. I just did mine and there was no pooling at the bottom. Start at the top and work your way down, using slightly less sealant as you get near the bottom.

      • Jeff Patterson October 30, 2014, 4:41 AM

        Thanks Joe for you tip. This question does come up a lot about the pooling action. So any additional advice on the issue is fantastic.

  • krithika October 6, 2014, 8:20 PM

    Very informative post and video for a dummy like me!
    Our home has a small gap between the home and the concrete patio through out the perimeter where the patio meets the home. Do you suggest I can seal it the way you have suggested to prevent water intrusions?

    • Jeff Patterson October 14, 2014, 5:56 PM

      Self leveling sealant is a great way to go Krithika because it allows your patio to expand and contract.

      I think this would be a good solution for you.

  • Scott October 9, 2014, 11:08 AM

    Yep, I’ve done this. and it’s a P.I.T.A. LOL.

    • Jeff Patterson October 14, 2014, 5:50 PM

      For real Scott, it’s no fun at all.

      And I have to do it again!!!

  • Noah October 20, 2014, 1:39 PM

    I’m looking to complete this project on my driveway, but I’d also like to use a densifier/waterproofer on it. Any recommendations on which should come first?

    Thanks!

    • Jeff Patterson October 22, 2014, 5:53 AM

      Hey Noah, that’s a great question and I’m not sure. Here’s what you can do though. When you figure out the products you’ll be using give the technical support lines a call. I bet they’ve gotten this question and will be able to help you out.

      Please, if you don’t mind, let me know what you figure out because some of our members will be curious too :D

  • Rachel December 1, 2014, 4:46 PM

    Hi Jeff…I read your article & all comments. You’re so cute! I priced all this stuff out 4 yrs. ago and it was too expensive for me to do my old 75yr old driveway…so I know it would cost even more now. My solution was to buy black asphalt patch in pourable jug and pour that in my humungous expansion joint gaps which are in some places close to 2 inches wide and VERY deep. I pulled out all the old rotted wood where I could.

    I haven’t done this project yet but what do you think about using the material? I can’t afford $400 for foam rod & copious amount of tube sealant. Besides since my concrete is so old & beat up the cost for those items seems silly.

    Let me know what you think Jeff! I bought the jugs when they were on sale….if it works the whole double drive will have cost me about $25 tops to repair the joints!

    xoxo
    Rachel the HandyWoman

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