The Anatomy of the Underpin #myreno
Our underpinng (basement lowering) job is finished and we couldn't be happier. Our contractor, Saverio from Cornerstone Waterproofing was amazing. His crew (Kyle, Kyle and Charlie) were polite, clean and accomodating. I can highly recommend them without hesitation. Saverio will go above and beyond what is asked of him.
These pictures detail the process of the underpin. It took 3 weeks to complete. Most contractors will take 4-5 weeks to complete this kind of job. Saverio and the crew worked hard to complete this on time.
Underpinning a house is a major structural undertaking. You are lowering the original footings of the house to a new, lower depth so you can lower the floor.
This is obvioulsy the beginning. We needed an engineers report to document the specifics. This is only 1 page out of the 6 page report. This is also mandatory to get permits from the city. The basement was cleared out, the sections were labeled 1, 2, 3 and then the wooden forms were made to pour the concrete in.
The soil is excavated in sections. First the #1's, then they are underpinned. The forms are put in place then as per the engineers reports, a large 9" piece of angle iron is placed in the concrete that goes from the bottom of the new pin to the ceiling. Some contractors and engineers think this is overkill but it doesn't cost much more and certainly helps the house. In fact, half of the contractors had never heard of this!
Once all of the sections had been underpinned it is time to excavate. Kyle, Kyle and Charlie break their backs shoveling the soil onto the conveyer belt. Our furnace and hot water tank had to be "strapped" to the floor joists to be able to excavate underneath it. It it be moved to another location.
New plumbing lines are installed removing the old clay ones. We had a 90% blockage in a 4 foot section! The gravel is poured to make way for the concrete. On top of the gravel a 6mm vapour barrier is placed, then metal wire, then concrete. A black drainage board is placed on the inside walls as a water management system that drains into a weeiping tile system that leads to a sump pump. There is also a backflow preventer that was installed at the front of thouse to prevent sewage backflows.
This is the finished product. One small 13'x38' room that will cost a fair bit of money but will give us the much needed space that we desire.
Assessed Value of $407,374: Estimated property tax = Assessed Value x 
