Basement Lowering/Underpinning

If you are looking for a more livable space in your home, the basement is the first place you should look. But what if your basement is unfinished or needs to be lowered to provide a comfortable space for your family? This is where the process of basement lowering or underpinning as it is commonly known as is important for expanding your living space in your basement.

In many older homes, the basement was never meant to be a living space with low ceilings and exposed ductwork reducing the amount of headroom. Basement lowering is definitely no easy feat considering the number of resources required. However, it goes a long way to expand your living space.

See the process in action!

Benefits of Basement Lowering

Also known as underpinning, basement lowering entails digging out the basement floor several feet down. This will add value to your home by ensuring the basement can easily be accessed and used. In addition, underpinning also enhances the integrity of the structure thus uplifting the face of your home. Generally, these basements are about 6 ft high, and lowering the basement by 2 ft for a total of 8 ft for headroom is the desired height.

Here are some terms and processes you will want to familiarize yourself with before you meet with a contractor.

Benching

The benching system is used to create extra living space. The benching system is a sister to underpinning system, it will allow you to create the same overall height gain but it minimizes your square footage. If the area is finished according to the benching system then this works for many applications. It is a system that is less costly then underpinning and takes half the time.

Benching Process

Basement Waterproofing Benching Process
Concrete poured and dried. Benching is complete.

First step is to have engineer drawings and permits

  • The concrete floor is removed
  • The soil is excavated to its proper elevations, pending on the height required will determine how far out from the wall the concrete needs to project
  • If you lower your basement 1 ft down then this means your concrete bench needs to be 1ft to 1 ½ ft out from interior wall
  • Once excavated the perimeter is formed for the benching to be poured
  • The new plumbing is installed, if the elevations for new plumbing cannot be meet then a sewer injector will be required.
  • The interior drainage system is then installed to waterproofing the property
  • A minimum of 3 inches of ¾ gravel is placed on floor for base
  • Then new concrete floor is installed and trowel finished

Underpinning

The underpinning system is used for one main reason to create extra living space. This system will allow you to increase the overall height of your basement and the square footage. Most home owners choose to go this route because it gives them the options to use their basement as a rental property which in return will give them a source of income, or to gain a fully finished basement and increase their living space.

Process for underpinning

Basement lowering and underpinning
Underpinning Completed

First step is to have engineer drawings and permits.

  • Concrete floor is removed and the soil is excavated to proper elevation
  • The pins are dug out in sections according to the engineers drawings, typically in three stages
  • If new posts are required then new footings for posts are installed, which means temporary jacks are installed to support beam
  • After the first stage of pins is completed there is a 2 inch space between the existing footings and concrete where a 2 inch dry pack grout is installed.
  • Once all three stages are completed, the new plumbing is installed, if the elevations for new plumbing cannot be meet then a sewer injector will be required.
  • The interior drainage system is then installed in order to waterproof the property
  • A minimum of 3 inches of ¾ gravel is placed on floor for base
  • Then new concrete floor is installed and trowel finished

Basement lowering goes a long way in giving your home a complete makeover. However, it is a huge job that will affect the overall structure of your home and you have to do it right. Don’t take any chances or cut corners and make sure the company you choose to do the work has underpinning and liability insurance.

RCC Waterproofing is fully insured and happy to provide customer references.

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