How to add expansion joints between wall and concrete paver?

[kashifrana]

My Building inspection report before buying mentioned under minor defect "Installed concrete pavers are lacking appropriate expansion joints, there is an increased risk of cracking to the concrete pavers, as well as potential damage to the adjoining brick walls due to the stress from thermal expansion. It is recommended that qualified professional be engaged to assess the extent of the issue and add expansion joints where required."

My questions are:

1- Adding expansion joints between wall and concrete paver is even possible in already built concrete paver or paver needs to be rebuilt if it is that bad?

2- There is a very small gap between walls and concrete paver (shown in picture). Is it ok/enough to fill with backer rod and self leveling sealant as weeds are kept coming out of this gap and my concern is filling that gap should not create stress/pressure condition to cause cracks in paver or wall?

Appreciated your input

small gap

[JacobZ · Accepted solution]

Hi @kashifrana,

Thank you for your question about the expansion joints that were flagged in your building inspection report.

It looks like the concrete pathway was poured after the brick was already in place without any consideration for expansion.

Unfortunately, the crack you have doesn't look wide enough to retrofit an expansion joint.

The solution that is likely required is to cut or grind out a space wide enough to install Abelflex Expansion Joint Filler Foam, then cover it with Sika 600ml Concrete Grey Sikaflex Pro+ Polyurethane Sealant.

I'd suggest contacting a concrete cutting company for their assistance with widening this crack so you can retrofit an expansion joint. You can use a service such as HiPages or True Local to find companies that do this kind of work in your area.

You can then follow the process in How to fill a joint in a concrete slab to install your expansion joint.

Let me know if you have any further questions.

Jacob

[kashifrana]

Hello Jacob

Thanks a lot for your great suggestion. In your opinion, if I just pour some Sikaflex in these small gaps to block water seepage then would ti be sufficed at this stage? as the pathway is already 7-8 years old and did not cause cracks in the wall

[JacobZ]

Hi @kashifrana,

There is still potential for cracking in the future, but if the concrete was going to crack or cause damage to the brickwork, I imagine after 7-8 years there would already be signs.

If you were just looking to block the weeds from growing, then this would not increase the potential for damage in any way.

Let me know if you have any further questions.

Jacob

[alyse2]

Hi there, I also had a similar thing come up on my building report. My house is 46 years old though, so is it even worth putting isolation joints in? Or just filling with sika?

[alyse2]

We have had some minor things come up regarding the floor being out of level in some rooms, some small cracks but nothing major. 

[MitchellMc]

Welcome to the Bunnings Workshop community @alyse2. It's terrific to have you join us, and many thanks for your question about expansion gaps.

It depends on whether you're experiencing any movement issues due to the missing expansion joints. At 46 years old, the house has likely settled, and if you're only seeing minor cracks, it may not be a significant concern. If there's no noticeable movement or large cracks forming, filling the gap with a flexible sealant like Sikaflex could be a practical solution to prevent water ingress and further deterioration. However, if you're noticing ongoing movement or larger cracks developing, installing proper isolation joints might be worth considering to allow for controlled expansion and contraction.

It sounds like you might need to have a structural engineer look over the report and qualify whether the issues that have been identified could be the result of the expansion joints.

Please let me know if you have any questions.

Mitchell