How to fill gap between house and concrete path?

[jenniferji]

Hi everyone,

our house is 15 years old and there is a gap between the house and concrete path. How to fill the gap to prevent water damage the foundation? Thank you so much.

 

[MitchellMc]

Welcome to the Bunnings Workshop community @jenniferji. It's brilliant to have you join us, and many thanks for your question about filling gaps.

That's an expansion gap between your house slab and the pathway. It's not a seal that prevents water from entering and is there to isolate the pathway and prevent cracking. However, the gap has widened, and the expansion gap is not filling the area. For aesthetic reasons, you could fill the gap with Sikaflex 11FC, but there's not a great deal of concern about water entering and damaging your slab. There are plenty of other areas around the home where sub-surface water will reach your slab.

I'd recommend cleaning out the expansion joint and caulking the Sika product down behind it until it fills the area. You can then run a gloved finger over it to smooth off the surface.

Please let me know if you have any questions.

Mitchell
 

[jenniferji]

 

 

Hi Mitchel,

Hope you are well.

i have another DIY project. I want to put the caulk between the concrete pave and whole house above ableflex like the 2nd photo. Which product should I use 11FC or 11FC plus polyurethane adhesive sealant or other products?  Also could I also have some tips please? Do I need to clean before I apply the silicone?  Thank you in advance 

[JacobZ]

Hi @jenniferji,

It's great to see you're getting around to this project and the drawing you've provided is spot on.

Since the time of your original post, I have done a similar project in my shed. You can see it here - How to fill a joint in a concrete slab?

You'll see that step one is cleaning up the crack, which is essential to getting a quality seal. I used a screwdriver to agitate any dirt that was in the crack and a Makita 18V Blower to blow it out. If you don't have a blower, you can use a pressure washer, or even a garden hose and a brush to clean the crack. You're aiming to create enough space for the Abelflex to sit in the gap nicely.

Once clean, use Abelflex and Sika Concrete Grey Sikaflex 11FC Purform with a sausage caulking gun to seal the gap. You'll need a fair bit of Sikaflex for a long gap like this, so grab a few. If any sausages of Sikaflex are unopened, you can always return them with your receipt.

In my project, I was looking to create a functional seal rather than one that is particularly aesthetic, so I've skipped this step, but using painter's tape to mask off your bead of silicone will help you get nice clean lines. You can see an example of this in How To Silicone Seal a Bath Tub.

Make sure you have rags and some soapy water nearby as cleanup is going to be very important.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[jenniferji]

Thanks Jacob. May I know what is the difference between 11FC purform  and 11FC plus polyurethane adhesive sealant? 

https://www.bunnings.com.au/sika-600ml-concrete-grey-sikaflex-11fc-purform_p0628966

https://www.bunnings.com.au/sika-600ml-grey-sikaflex-11fc-plus-polyurethane-adhesive-sealant_p016999...

[JacobZ]

Hi @jenniferji,

In simple terms, they are two progressions of what is more or less the same product. 

To use an analogy, think of a 2023-model car, a 24 and 25-model car. They are very close to the same thing with some minor improvements.

• 23 model - Sikaflex 11FC
• 24 model - Sikaflex 11FC Plus
• 25 model - Sikaflex 11FC Purform.

Sikaflex 11FC is an older version that is no longer available, Sikaflex 11FC Plus is the next progression and Sikaflex 11FC Purform is the newest progression.

I couldn't tell you the exact difference in terms of chemical composition but, this should give you a good idea. As the cost is the same, I'd suggest using the Sika 600ml Concrete Grey Sikaflex 11FC Purform.

Let me know if you have any further questions.

Jacob