Concrete slab erosion and repair

[as1430txstate]

I’m fixing to acquire this mess of a pool equipment slab. What kind of repair does this need? Looks like a good amount of erosion taking place with yard. Perhaps patch work on bottom of slab and then compacted soil brought in and secured with posts driven into ground (small retaining wall)? Total pool newbie here. Appreciate all the advice!

 

[cowboycasey]

looks like all the water runoff on the pool deck, your house and above your house all go down this hill that the equipment pad is on.. all that runoff is taking away the soil little by little... You need to do build up that whole area with rocks like they do when they have runoff on roads or bridges or anything like that..

See how they have done this for runoff, you will need big and small rocks to fill in the area so it no longer takes dirt out and the rocks slow the runoff down.. you will also need gravel to fill in the area behind your pump pad and in front of it to stop the dirt from eroding then install the bigger rocks on top of that...

 

[CJadamec]

I agree you should line the hill in rock to limit the errosion being caused by runoff.

You should try and backfill that erroded corner with some clean fill if you can. After you do that put a layer of geotextile fabric down to hold the soil in place then a layer of rock to hold the fabric down.

Or figure out how to divert the run off up hill of the pad to prevent it from going around the pad.

 

[as1430txstate]

Appreciate y’all’s advice! I don’t have much experience with concrete (only a fence post or two)- is the fill work something I could do, or does it require some special tools to get underneath the slab?

 

[CJadamec]

By fill I just mean clean dirt with out big rocks.

You dont want top soil with lots of organic material.

Use the fill to replace the solid that was lost. Try to get some back up under the pad. But that's not too critical just for appearance really. Use fabric and rocks to hold the fill in place.

It would be very beneficial to the repair to deal with the water run off up hill of the slab.

 

[cowboycasey]

A shovel and some dirt and something to pack it under and around it...

This one is 8x8 https://smile.amazon.com/Companies-Inc-2233400-Steel-Tamper/dp/B00L1LGT0W

Use this one to pack dirt up under the slab. Husky 69 in. Post Hole Digger and Tamping Bar-34219 - The Home Depot

Once the dirt is around the slab put the fabric down then the smaller rocks then the bigger rocks.. You will take the rocks almost all the way to the waterline... It is easier to get tons of rock delivered, I just had 13 tons of 3/4 clean gravel to fill holes for less than 300 dollars... You will probably only need 2 to 3 tons of small rock,1 to 3 inch and then a ton of bigger rock 3 to 6 inch should do nicely...

It is going to be fun getting the rock down there...

 

[as1430txstate]

Great advice- thank you cowboy and CJ. Would a French drain (with drain that sits above the equipment slab) that empty’s into lake be a good idea to prevent future erosion after doing the dirt and rocks?

 

[CJadamec]

A french drain would certainly help.

 

[duckcmmndr]

Like others have said...tamp some fill up under the slab and pack it with anything that you have...a short piece of 2x4 will even work. Then cover with fabric and rocks.

Do you have deck drains up around the pool?

I noticed this pipe and it appears to be a source for water that has been running and eroding the ground around your slab. It might be good to glue and 90 and a short piece of pipe on it to direct the water flow down and away from the slab...like the blue line.

 

[CJadamec]

Like others have said...tamp some fill up under the slab and pack it with anything that you have...a short piece of 2x4 will even work. Then cover with fabric and rocks.

Do you have deck drains up around the pool?

I noticed this pipe and it appears to be a source for water that has been running and eroding the ground around your slab. It might be good to glue and 90 and a short piece of pipe on it to direct the water flow down and away from the slab...like the blue line.
View attachment 338257

Nice catch on the drain pipe.

 

[as1430txstate]

Nice catch on the drain pipe.

Haven’t moved into the house yet, but I do recall it having drain grates up on the decking. Thanks for pointing that out! Probably a huge contributor to the erosion.