The Cost Of Repairing A Sinking Driveway
Contractors will charge you any where from $1000 to sometimes $5000 to repair a sinking driveway.
However, with the right tools and with this step by step process, you can do all that on the cheap.
Tools You Will Need
- A Grinder
- A Diamond Blade
- A Dust Mask
- Wheel barrow
- Soil Compactor (Tamper)
- Chalk Line
- Crowbar/Sledgehammer/Demolition Hammer
All this should cost you roughly under $300. Thats assuming you buy/rent all of the gear. You will probably have some of these things laying around the house though.
Materials You Will Need
- Some scrap wood that will cover the sunken portion of your driveway
- Cold Patch to fill in the excavated hole (asphalt driveways)
- Concrete mix
- Concrete bonding agent
Step One – Outline The Sunken Portion Of Driveway
With your chalk line, measure outline the area of your driveway that has sunk. This will require two people.
Place one end of the chalk line 4 inches from the sinking portion and place the other end of the chalk line inches past the end of the sinking portion. Snap the chalk line so you now have a straight line extending 4 inches away from the sinking hole.
Do this on each side so you eventually have a box surrounding the sinking portion of the driveway with a margin of 4 inches.
Step Two – Cutting & Cleaning
Put your dust mask, glasses and ear muffs, if you have them, on. Attach the diamond blade to your grinder and cut the surface.
Ensure that the cuts are made along the line you marked out with your chalk line.
Once the cuts have been made, use either your sledgehammer or demolition hammer to breakup the concrete/asphalt for easier removal. If the section is small, you can use your crowbar with the help of a wedge, to lift the slab out.
Otherwise, once have finished breaking up the slab, you should start removing all the rubble. Clear away as much as possible so that the bottom soil is exposed.
Ensure that you dig up any loose sod. If the sinkhole is man made i.e caused by buried rubbish or tree stumps make sure you remove these as well.
Step 3 – Compact The Bottom Layer
Once you have removed all the loose soil and you have a nice hole where the sunken portion of your driveway was, its time to start compacting.
Below is a photo two men compacting soil with gasoline soil compactor. This will make the job a lot fast if you have exposed a lot of earth but a simple tamper will do the job if you only have a few feet of exposed earth.
Using your tamper (soil compactor), press the soil on the floor of the hole till it is nice and hard. This is extremely important. If the base is not compacted the soil will compress overtime resulting in a dip in your newly sealed surface.
Step 4 – Fill The Hole With Cold Patch (Asphalt Driveways)
Start filling the hole with about 4-5 inches worth of cold patch. Every 4-5 inches compress the cold patch with your tamper.
As tempting as it might be, do not completely fill the hole and then try and compress the asphalt. You will not be able to apply as much pressure to the asphalt as your car will. Compressing the hole in intervals in therefor recommended.
If your driveway is made of concrete, layer the hole with a concrete bonding agent. This is best done with a paint brush so you can get every nook and cranny.
Once all the sides are painted, fill the hole with some wet concrete while the bonding agent is also still wet.
Step 5 – Compression
If you filled the hole in your driveway with cold patch, it is time for the final step. Put the scrap wood on top of the asphalt which should be level (or slightly higher) than the rest of your surface. You can test this using your level.
Now drive your car onto the wood so that the car is now compressing the cold patch.
We recommend that you leave your car like this for the night so that it can properly compact the cold patch. Come back in the morning and if the asphalt is sitting a bit lower, re-apply some more cold patch and repeat the process with your car.
We recommend you leave the ply wood on the asphalt for up to 30 days as the cold patch will take this long to cure. Any sooner and the tread on your car tyres can cause indentations.
You can see if the surface is flat using your level.
For concrete, once the mix has set, check if there is any sinkage (lower surface height relative to the rest of the driveway). If this is the case, use some more concrete mix and apply that finishing layer.
That pretty much wraps it up!
If you have any questions feel free to ask or if you have any comments, chuck them in below,