Why Is There Gravel In Sump Pit?

Here is why there is gravel in your sump pit.

The process of installing a sump pump is quite delicate.

It’s delicate in the sense that a careful arrangement of the substrate beneath the basement floor is required for the proper functioning of the sump pit. Part of substrate materials includes gravel, and drain tiles.

Gravel At The Bottom Of A Sump Pit

Here, we’re most concerned about the inclusion of drain tiles in sump pit construction.

What purpose does this serve? If you’ve asked a similar question before, you’ll find this article quite informative and an interesting read.

Without delay, let’s provide all the answers to your pressing questions like the one above.

Sump Pit Design

Designing a sump pit requires the use of various materials.

These range from pressurized fittings to silicone sealants. Others are wire ties, J hooks, gravel, check valve, PVC pipe, sump pump, corrugated pipe, and cement.

Of these materials, gravels serve as a solid base upon which the pump rests. This helps support its weight. It’s important to only use coarse gravel when building a sump pit.

Of course, such a job should be handled by a waterproofing expert or contractor.

Why Gravels?

To build or construct a sump pit, some level of excavation is needed.

Now, a typical sump pit measures around 36 inches deep and 24 inches wide. This is enough to hold a sump pit insert of about 26 gallons. To accommodate the gravel base, a sump pit will need to be dug an additional 12 inches deeper.

This totals to a depth of about 48 inches (that is 36+12).

Having reached such depth, what remains is to return the dug floor to grade. About 3 to 4 inches of coarse gravel will need to be added to the floor.

The addition of gravel promotes the movement of water sideways to the region of the sump pit before moving up.

Also, gravels enable easier movement of water upwards as it presents less resistance.

  • A Sump Pump Should Never Sit on Loose Silt

We’ve stated that a sump pump requires a solid, yet porous base.

This is where gravels come in handy. Another material that, though porous yet is unsuitable for use as a sump pit base is silt. Whenever silt is used, it’s easily sucked right into the pump.

Of course, this continued action is likely to result in the breakdown of the pump. Asides from silt, one other material that shouldn’t be used are small-sized gravel.

Surprised? You shouldn’t be. There’s little difference between a small-sized gravel base and silt.

These can easily be pulled or sucked into the pump. You’re likely to end up with a similar issue. Asides from coarse gravel, no debris should be used as a base. Large rocks can also be considered in place of coarse gravel.

We’ve only mentioned the possible malfunction of a sump pump when silt is sucked in. A more complete explanation will include the clogging up of drainage lines.

When debris gets into the pump, it steadily accumulates in the drain lines. This eventually narrows the passageway, thus making it increasingly difficult for free flow of water.

  • Float Switch Problems

There has to be sufficient space in a sump pit for the float switch arm to move back and forth.

Sump pits with gravels make the pits easier to maintain as there is less debris that stalls the free movement of the float switch arm.

Use the Services of An Expert

An experienced plumbing or waterproofing contractor is best suited for sump pit construction and installation.

While there’s a clear reason why gravel should be among the material of choice for sump pit construction, such knowledge isn’t enough for DIY enthusiasts.

It’s best to have a pro handle the procedure. This ensures that the right amount or quantity of gravel is used. Also, only the right gravel size should be considered. This has been mentioned earlier to be mainly coarse gravels.

In the absence of gravel, large rocks can be considered. However, only a pro knows how best to use such material. Here, the need to involve a professional contractor cannot be overstated. It helps you avoid all sorts of common errors.

Plus, basement sump pump installation and waterproofing is a delicate job that requires all the expertise you can get.

Can Areas with Rocks Replace the Need for Gravels in Sump Pit?

This is a technical question that requires the input of an experienced professional.

There may be underlying soil conditions that require further assessment before any conclusions are made. In a nutshell, you’ll need the help of a trained and experienced technician to find answers.

There Should Be Enough Room for Gravels Around Sump Pit Liner

It’s not enough to have gravels at the base of a sump pit.

That is because the water flows from all sides into the sump pit. So, while laying gravels at the base of the sump pit it needs to be poured also around the liner.

This calls for wider excavation of the sump pit.

Basically, your hole should be dug in a way that allows about 6 inches of space for gravel all around. The hold should be dug deep enough to ensure the liner is flush with your basement floor.

The gravels placed around the liner serve the same purpose as those at the bottom of the sump pit. Only water accumulates without debris and other forms of dirt.

Gravels Lock the Sump Pit Liner in Place

One of the benefits of having gravels among materials for sump pit construction is the fact that it locks or holds the pit liner in place during construction.

When properly laid around the sump pit liner, the area is capped with concrete.

This requires careful placement to ensure the liner is properly installed. Whether you can do this as a DIY project depends on your level of experience.

If your skills in this area are limited, it’s best to have such jobs handled by pros.

Your Sump Pump Serves Longer

When the right procedures are followed for sump pit construction, you have a situation where the system lasts longer. This is due to the absence of clogs or any other issues.

Of course, such stability can be attributed to gravel use.

Have we satisfied your curiosity? The above reasons are why you have gravel in a sump pit. It serves a need that cannot be ignored.

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