The Basics of Basement Lowering (Underpinning)
Updated: Aug 6
This blog discusses the basics of basement lowering/ underpinning.
Underpinning, also known as basement lowering, often includes;
i. Lowering the basement floor
ii. Adding floor drains
iii. A laundry Room
v. Stud wall partitions
vii. Reinforcing the foundation
viii. Basement Walkout (occasionally)
The cost and project time depends on the work being carried out.
Methods of Underpinning
There are several different underpinning methods that can be used to lower
your basement. The best method to use depends on your foundation, soil type, budget, and desired height increase. You can dig a basement as deep as you please, but remember, the deeper you go the greater the cost, and if you would like to go further than eight feet, the foundation walls may need to be reinforced.
Preparing for Underpinning
Before you get started, drawings and permits need to be taken care of (A structural engineer will take care of these). Obtaining permits usually takes two weeks and sometimes even longer. The cost of the permit depends on the linear footage of the job and includes the draining and plumbing.
Tips for Finding a Qualified Underpinning Contractor
· It’s very important to find a properly licensed contractor who is insured for underpinning work (This particular job isn’t covered by the company’s general liability insurance).
· Always ask to see a copy of the insurance certificate and look for a minimum of $2 million coverage. It should also include your name and address.
· When searching for a contractor, you may want to ask for references and a portfolio of their previous work.
How Long Does Underpinning Take to Complete?
Similar to other home renovations there may be unforeseen issues. If this is the case, it will typically add some time to the project. However, a typical underpinning job usually takes four to six weeks.
Remember: Most of the time this doesn’t include the finishing work.
Other factors that influence the length of the job: include job conditions and engineering details. For example, water lines, water meters HVAC systems, electric panels, and/or basement stairs may need to be moved or re-installed.
It may cost a little extra but exterior waterproofing is always recommended. A backup sump pump system is also recommended to remove water during power failures.
Feel free to contact Nusite Contractors Ltd. to learn more about underpinning and its process. We are fully certified and insured in contracting work, and can take care of all of the pre-planning work. We take care of the drawings and obtaining the necessary permits.
Nusite Contractors Ltd. has been proudly serving GTA homeowners for over 30 years! We are a family business and take pride in customer service and professional work. You can contact us here to schedule a free consultation and written estimate! We would be happy to help!