Filling in a basement is a complicated task. Basements can be filled in at construction stages, after construction, or at remodeling a house.
Many people living in flood-risk areas start to fill in their basements either as a safety measure or to simply comply with insurance regulations.
Filling in a basement is a complex task that requires measuring tools and the agreement of an engineer. Otherwise, it’s just a temporary fix until the ground starts to settle.
How to fill a basement to prevent flooding
You can fill a basement to prevent flooding when you decide to rebuild the house. You can use old basement walls or build new walls if there’s no structural damage.
Water makes its way to the basement easily if the soil is not perfectly compacted. Make sure to clear all electricals from the basement before filling them in.
Compaction refers to the degree of actioned soiled contraction and is measured by engineers with special gear. A 95% degree of compaction is the standard of compactness suitable for a basement that’s filled in that would otherwise be similar to building on solid ground without a basement.
How to fill a basement to rebuild the house
Filling in a basement after the home is ready to simply remodel it or to eliminate the basement isn’t possible as it prevents compaction.
A full basement where you simply dump earth and sand is not going to prevent flooding and it’s not going to offer any structural support.
The basement is filled in layers. Each layer has around 6 inches. Single layers are compacted after poured before pouring the next layer until the basement is full. The final result is compact soil with a degree of compactness equal to or higher than 95%.
How to fill a basement that’s not built on
Let’s say you want to fill in a basement that’s not under your home. Those basement stairs next to the house come to mind.
In the case of the basement that isn’t under a building (side basement), you can consider filling it yourself. This involves layering. Sand, rocks, and cement are typically layered.
The more cement you use to fill in a basement the more the project costs. The more rocks you use to fill in a basement the more structural integrity the cement will have without sinking-in risks.
Sand can be used up to 20-30% of the total basement height. Small and large rocks are then added on top. Sand is then added again as an optional step. Cement is poured on top.
As cement makes its way down it solidifies to concrete permanently filling in a basement. This structure is generally safe to walk on but not safe to drive on unless planned with an engineer.
The Federal Emergency Management Agency has its own rules when it comes to filling in basements. For your home to be FEMA-safe it might require basement filling in, especially when there’s a risk of flooding.
Apart from the fill inside the basement, homes need to have adequate fill around the basement according to FEMA. Make sure you discuss these plans with an engineer if you’re filling in a basement to comply with insurance or regulation.
Otherwise, filling in basements is a laborious and often costly process. Unless it’s a small project it needs to be planned properly. Local authorities and engineers are often involved.
But if you’re planning to fill in a basement to build on you simply cannot just pour in a filler and lay a slab on top. The filler has to meet compactness standards.