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How to fix cracked garage drain?

varmahes

Hi it’s my first time here. I’ve just bought a house and am getting into DIY to fix stuff around.

I’ve got a driveway drain which is essential a concrete cutout with rails on it. I’ve noticed the concrete has cracked and I’m able to lift it with my hand itself. When it rains, water is rushing through this drain but because of the cracked concrete it’s seeping in and there’s multiple cracks on my driveway and inside my garage.

Any recommendations on a DIY solution for this? I was thinking of either getting an everhard easydrain but not sure if it would work with the car going over it. Any thoughts on best way to fix the cracks in my drain?

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MitchellMc

Welcome to the Bunnings Workshop community @varmahes. It's terrific to have you join us and congratulations on your new home.

From your photos, it looks like the sides of the existing concrete channel are still in reasonably good condition, apart from the hairline cracks in the pebblecrete. The loose section in the base of the channel appears to be the main issue.

The simplest DIY option would be to remove all of the loose and damaged concrete from the base of the channel, clean the area thoroughly, and then re-pour fresh concrete into the void. Once placed, you can screed it smooth to recreate the base of the drain channel. This should help prevent water from escaping beneath the channel.

If you're considering replacing the drain altogether, an Everhard EasyDRAIN system is certainly an option. The polymer grates are designed to be driven over when installed correctly, making them suitable for a driveway application. Just keep in mind that you may need to adjust the dimensions of the existing concrete trench to accommodate the new channel, as it may not be a direct fit.

It would also be worth checking that the outlet isn't blocked and that water is flowing away freely, as standing water can contribute to ongoing damage.

Please let us know how you go or if you have any questions along the way. We'd be happy to help.

Mitchell

varmahes

Thank you Mitch! That’s really helpful.
I’ve been doing some reading and wondering if rebuilding the drain base with concrete is a good idea since it’s a porous material. Do you have any recommendations or considerations I need to keep in mind with concrete as a material when it’s being used as a drain base?

Lastly, if you can help guide me with the material brand and tools I’ll need for this project it’ll be much appreciated. Thank you!

MitchellMc

You're very welcome @varmahes.

Concrete is actually the standard material used for forming drains like this, so it's perfectly suitable for rebuilding the base. While concrete is porous, in this application the goal isn't to make it completely waterproof, it's to create a durable, solid channel with the correct fall so water is directed quickly to the outlet. Once the concrete has cured, you could also apply a concrete sealer if you'd like to reduce moisture absorption and help protect the surface over time, although it's not essential.

The most important things to keep in mind are:

Remove all of the loose and cracked concrete back to solid material.
Clean the area thoroughly so the new concrete bonds well.
Use a concrete bonding agent if you're pouring against existing concrete.
Maintain a slight fall towards the drain outlet so water doesn't pond.
Allow the concrete to cure fully before exposing it to traffic.

If the area is quite shallow, I'd suggest using a quality repair mortar such as https://www.bunnings.com.au/sika-20kg-sikaquick-2500-au-rapid-hardening-repair-mortar_p0760435 or https://www.bunnings.com.au/dunlop-5kg-ardit-rapidset-repair-mortar_p0760262 , as they're designed for patching concrete and develop good strength. If the repair ends up being quite deep, a standard concrete mix would also be suitable.

The tools you'll likely need are:

Cold chisel and club hammer to remove the loose concrete.
Wire brush.
Stiff broom and bucket.
Mixing bucket.
Brick trowel.
Straight edge.
Spirit level to help maintain the correct fall.

Take your time with the preparation, as that's what will have the biggest impact on how well the repair lasts. If you can post a photo once you've removed the loose concrete, I'd be happy to have another look and let you know if anything else should be addressed before you pour the new base.

Mitchell

varmahes

Hi mate, planning on doing this DIY fix this coming weekend and had a few things I wanted to check on.

You mentioned Dunlop Mortar as the material of choice. Will this be sturdy enough if I've got cars going over it or should I go with a traditional cement instead?
The site can be divided into two parts.
1. Part A: Cracks on existing concrete. Will need to removed with a chisel and hammer
2. Part B: Lose concrete which can be taken apart by hand and reveals the underlying soil.
Is the recommendation to remove the entire horizontal concrete layer and pour in the dulop mortar directly over the soil to create a trench? Alternatively, is it recommended to simply remove the lose pieces by hand and pour over the mortar in those areas where soil is exposed + over the cracked concrete in Part A to create a trench?

Lastly, if we look at the last picture it has vertical concrete layer. Do I need to chip this bit as well before pouring the Dunlop mortar or do I need to use a bonding agent out here?

Trying to make sure I get the fundamentals and plan for this repair right. Thank you.

EricL

Hello @varmahes

Yes, according to the information on the website it say's "Structural repair material for concrete roadways, parking structures, bridges, dams and ramps." However, please note that there are a number of factors that must be taken into account which include thickness of the application, current condition of the surrounding concrete and application method. If the surrounding concrete is no longer viable or is structurally unsound then it will not be able to hold up heavy weights.

If you are only patching certain damaged sections, then using the mortar is the way to go. But for full replacement of the concrete base, I suggest using concrete mix as suggested by my teammate. You'll need to decide which parts you'll be patching and which parts you'll replacing in full.

Repairing small broken sections can be patched with mortar, it's best practice to use a bonding agent even when doing small repairs. Once you've removed the broken pieces of concrete you can place new concrete in that location. Mortar specifically is made for patching not as the main base of the drain.

My best advice is to physically push the broken sections on the side and make sure that they are still sound and not loose. Any section that comes off by hand will need to be removed and replaced.

Let me call on our experienced members @Dave-1, @Nailbag, @Noyade and @DIY4Knuckleheds for their recommendations.

If you need further assistance, please let us know.

Eric

Dave-1

Good Evening @varmahes

I would be pulling out the loose base as well. I would remove it back to the soil if possible (depends if any of the old concrete is still solidly connected to the slab) and then repouring the base with the concrete that @MitchellMc has recommended. I dont trust the mortar to do the long term job. I also like the metal grill that you have and would not be switching it out. Trying to get an old fitting (the concrete channel) to fit a new product (the easy drain) is problematic as well. I installed one next to one of my retain walls and it has risen one end slightly (I probably installed it incorrectly :) but it shows what can happen.

The chip on the side I really wouldnt worry about. The cracking you have could be from a number of things not linked to the drain failing. It would help yes but it depends on how the driveway slab was laid in the first place.

Dave

varmahes

This is great! Thank you Eric, Dave & Mitch.

Started working on a small area with a cold chisel and club hammer. Getting a bunch of pebbles in the soil when I break apart the concrete layer. Assuming a new layer was poured over the existing exposed aggregate layer - would this be a correct assumption based on the picture?

Going to get this back to soil and the make a concrete trench. Fingers crossed I’m able to get it right!

Dave-1

Evening @varmahes

Just go slowly as you dont want to break up more than is needed or make a bigger hole. If you can go to the side and dig slightly you may be able to see the profile of the slab and drain? It does look like its breaking clean :) So crossing fingers for you.

Dave

EricL

Hello @varmahes

That is very sound advice from @Dave-1. Take your time and don't rush the repair or remove more than what you need to. My best advice is to tamp the soil so that it is flat and compressed. This will give you a nice foundation for the concrete.

Eric