​Foundation Underpinning Foundation underpinning is our main service, and our ability to do it safely under the most challenging and complex conditions, sets us apart in the industry. The Underpinners Inc was started with a central goal in mind - to do one thing better than everyone else. This is it. Excavating under existing foundations of a house and extending the foundations to a new depth allows homeowners to maximize both the size and quality of their home. The process also strengthens the structure of existing houses so that they are safe, durable and comfortable to live in for decades to come.

 

 

  

 

​Crawlspace / Basement Excavation During the process of underpinning, we tunnel into crawlspaces and basements, excavating large amounts of soil to create new livable spaces. We're able to extend the existing basements into adjacent crawlspaces to increase the basement floor area. This work is carried out strategically to protect against collapse and to ensure the structural integrity of the house above. We begin by cutting an opening from the existing basement area into the unexcavated crawlspace, and assess the condition of the foundations. We then choose one of the following options: 1. If the existing foundation is in good shape, we underpin it.2. If the existing foundation is not in good shape, we support the house, rip out the existing foundation and pour a new foundation all at once.3. If the existing foundation is not in good shape, we replace the existing foundation in sections. In each instance, our greatest priority is to protect the stability of the house, while dramatically improving the quality, size and height of the underground space. 

 

 

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​Basement Walkouts Some of our clients underpin their homes to turn their basement into a publicly accessible space or a rental apartment, requiring a separate entrance.  Many times, we have created basement walkouts during the construction of an underpinning, pouring the new footings even deeper at the door to prevent frost from heaving the foundation. 

 

 

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​Structural Alterations Creating new usable space underground often requires some significant structural alterations. In most of our underpinning jobs, we remove the existing masonry or wood columns and replace them with stronger steel columns and new pad footings at the new basement height for increased stability. Oftentimes we swap a wood beams for steel beams that can span longer distances between supports. Depending on our client's needs, we use creative ways to eliminate columns or load bearing walls to achieve flexible open plan spaces.

 

 

 

 

​Structure Stabilization An older house can move and settle for many reasons: if it has substandard or decaying foundations, if it rests on low-grade soil, if the earth is eroding nearby, or if it was poorly constructed. We stabilize residential structures that are currently settling, or have settled gradually over a number of years. Our first step is to brace the overall structure and take the load of the house off of its existing foundations. In some cases, we lift the entire house up with hydraulic jacks and place it on temporary beams and jack posts that rest on temporary pad footings. Usually, we are able to carry out our work below without having to disturb the structure of the house above. 

 

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​Shoring and Earth Retention Systems We have experience installing many types of earth retention systems, both temporary and permanent. These systems are commonly used to protect and support an adjacent structure from collapsing while carrying out deep foundation and excavation work. Well-executed shoring is essential in downtown Toronto, where houses are built in close proximity to one another. These systems come in range of size and complexity. During deep excavations, we use temporary sheet piled walls, solider piles and wood lagging, and large monolithic concrete walls to retain the earth in place as we work. We also install permanent earth retention systems to stabilize soil long term. These permanent systems are commonly installed where the soil beneath where the house sits is subject to erosion. We have the expertise and the specialized compact equipment needed to carry out most temporary or permanent residential shoring projects in tight access spaces. 

 

 

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​Lateral Reinforcement During underpinning, we assess the soil pressure, the type and condition of the foundation, and the thickness of foundation wall to determine if it requires additional lateral reinforcement. We provide lateral reinforcement for existing foundation walls that cannot support the lateral loads applied by the exterior soil. A common way to do this is by casting steel into the underpinning, which runs from the basement-ceiling joist down past the new basement slab level. Alternately, we install wood backup walls that are anchored into the concrete slab and the joists above, in order to transfer lateral loads to the newly framed walls.

 

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​Foundation Wall Replacement In cases of severely deteriorated foundation walls, a full replacement may be the only viable option for repair. Foundation wall replacements can either be done by temporarily supporting the entire house to allow for the entire foundation to be removed and rebuilt at once, or by shoring up all the loads and removing and replacing the foundation in sections. Both methods involve pouring new foundation walls and footings, and installing a new sill plates with anchor bolts. 

 

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​Liner WallsIn some cases, rather than replacing entire foundation walls, we recommend supporting existing foundation walls with new concrete liner walls, which allow the two walls to work together to support the loads above and resist soil pressures. This cost effective method helps to laterally reinforce the foundation while increasing the allowable loading.

 

 

 

​Water Management With dirt comes moisture - the deeper you dig, the greater the chance of water becoming an issue. Each of our jobs has an integrated water management component, to ensure that the finished house is protected from water damage. If an excavation area is very wet, we typically enlist a geotechnical engineer to investigate the depth of the water table, soil bearing capacity, and the soil type, so that we can establish a comprehensive water management plan. We take all of the necessary precautions to keep the moisture and water out of the finished space.

 

 

 

 

​Sanitary Drains Older homes in downtown Toronto typically have clay pipe underground sanitary drains that are often clogged with tree roots and debris. We replace these pipes with new PVC and ABS sanitary drains, and our clients are able to choose where they want to place new floor drains, depending on the location of bathrooms, kitchens and laundry rooms. We also install sewage ejectors or a new main line and backwater valve to prevent sewage backup.

 

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​Co-ordination with Consultants Structural EngineersEven though it is not required, we use a structural engineer on every project. This ensures that all structural issues are taken into consideration before a project commences, and keeps the project moving smoothly if a problem arises during construction. It is much harder to engage an engineer mid-way through a project. Soil EngineersWe recommend engaging a geotechnical engineer prior to preparing design drawings for an underpinning to determine soil bearing capacity, the soil type, and the amount of moisture in the soil. The soil engineer is then able to make recommendations for both the design of the underpinning and the water management plan. ArchitectsWe work with a trusted network of architects to create comprehensive design, permit and construction drawings, and to prepare the planning applications necessary to secure permissions for construction.