Toronto Basement
Underpinning company

1. Permits

   In Ontario you cannot start and structural renovation or construction without obtaining a city permits. This system is designed specifically to protect home owners and entire industry from unprofessional and incorrectly done jobs.

   First step is for architects to make design drawings with exact dimensions of the house. On these drawings we would see detailed work for basement lowering and specs literally for everything. It includes depth of excavations, length of sections, basement size, type of concrete and even slab thickness with amount of gravel required.

   ALBO Renovations can help with all necessary documents and drawings for city permit. By doing it in-house you can save money and time.

2. Foundation Sections

   After we get green flag for starting work and everything in the basement is prepped for lowering process, we immediately start with underpinning by sections. Foundation walls should not be excavated in full, therefore engineers propose digging down 3 feet at a time.

   Our crew excavates 5-15 small sections that are distanced away from each other for safety. Each section is prepared for inspection and framed for concrete pour. Later on concrete is put into section and we let is settle for a day or two.

   Each set of sections needs inspection by city inspector, structural engineer or both. ALBO Renovations takes care of all that for you.

3. Inspections

   We put inspections after sections, but in reality there will be many inspections during and after that process. Normally we would book city inspection and their representative can request additional review by engineer. In other words they don’t want to take on responsibility and rather have licensed engineer put a stamp on review.

   Later on there will be inspections of installed drain pipes and any additional structural detail we have in scope of work. It could be beams with posts, footing and foundation walls for addition or basement walkout.

   Regardless of what and when inspections are for, we take full care of it and our clients never have to worry about meeting engineers or city inspectors during basement underpinning job.

4. Full Excavation

   When sections are completed and fully cured, excavation only begins. Our team needs to break existing slab and dig several feet down for the entire space of basement. Imagine how much work is that, if we have to dig by hand.

   Average project takes 7-12 days to excavate middle of the basement at this stage and can have up to 100 tons of dirt with concrete.

   In best case scenario we would have access by small bobcat to excavate it from rear or side of the house. Otherwise conveyor belts are put in windows to transport all soil from basement directly into bins.

5. Drains

   During excavation all drain pipes under slab were removed and now we need to install new ones. Plumbers show us where toilet and stack connections will be for renovation and our team lays underground drains accordingly.

   All of this work is inspected by city official and permit moves on to next stage. Home owner can be present during inspection, but can just sit back and let us take care of it.

   To avoid installation of sewer injector pump, we may need to change drain pipe all the way to city connection outside. Depending on slope, but sometimes even this trick does not help avoiding sewer injector.

6. Waterproofing

   Every underpinning and benching work should include waterproofing of walls. We are excavating and exposing foundation walls, and there is no better time to do this work.

   Weeping tile is installed alongside perimeter of the house at footing height to collect and redirect any and all water that accumulates due to condensate, future foundation leaks and underground water. It is connected to water disposal system – sump pump.

   Further we fix all existing cracks and nail delta membrane to exterior foundation walls. Basement lowering involves reinforcement and protection of walls with prevention of leaks into new basement space.

7. Back Flow Protection

   There is a new way to protect basement and literally entire house from city sewers overflowing and backing up towards your house. ALBO Renovations will install back water valve – It is a system that connects to main drain line and makes sure nothing goes back towards the house.

   It is a prevention and security of basement that is recommended by all plumbers in Ontario. Money spent on backwater valve are returned back to home owner as a rebate from city.

   Ask our project manager for filled form that guarantees city rebate for this work.

8. Concrete Slab

   At the very end of Basement Underpinning journey, our guys order several trucks of concrete and pour basement slab. It is cured for several days and smoothened out for further use. New surface can be polished or covered with any type of flooring system during basement finish.

   Keep in mind concrete slab is not a structural support and cannot support posts with beams.

   Be sure to let us know if you plan to install heated floor system, because it is done by other trades prior to concrete slab being poured. ALBO Renovations can provide quote for radiant heat floor system if needed.

Here is a list of most common problems while increasing height in your basement:

1. Drain Slope

   The problem occurs when city main drain line is not that deep. Underpinning basement and installing drain pipes under new slab makes potential problem of having pipes higher than city main. In that situation we have to install sewer injector pump to unsure everything leaves the house.

2. Adjacent Walls

   Another obstacle in excavating basement is proximity to neighbours and adjacent walls. City examiners don’t like to encroach on properties and can deny permit if it looks like you are going to dig at the property line.

   If there is a danger of coming close to neighbour’s house or potentially damaging their foundation, engineer/architect may suggest doing bench footing instead of foundation underpinning. This is a safe bet and city typically allows that.

3. Limited Access

   Ability to work with machinery to excavate and transport soil makes the whole process much easier. This speeds up the project and we are able to save money for the client. Initially quote should be cheaper if we can use bobcats and excavators to lower the basement.

   Toronto is a mega city with many houses being built next to each other with less space in between. Unfortunately in many cases we have to dig by hand and it makes job more complicated than it needs to be.

4. Temporary Disconnects

   Home owners would like to live inside the house while underpinning of the basement is taking place. Besides noise and dust with construction, you will experience disconnects of drain, water and possibly electrical service.

   For obvious reasons our team needs to break and take out drain pipe during excavation. You cannot flush anything, go to shower and cook for the time of disconnects. ALBO Renovations strongly suggest home owners to vacate the house during basement underpinning for safety reasons and convenience.

5. Extra Support

   Extra issues arise once we start excavating. We take extra care of floor joists and existing beams of the house during excavation, but the houses we work at are typically very old. Architectural drawings do not specify details for safety; they just outlay existing and finished basement details.

   Our job is to make sure foundation walls are always intact and house structure does not move a bit during work. Even slight movement can lead to cracks in drywall and flooring.

6. Bad Foundation

   As you may already know, basement lowering is a service typically for very old homes that were built decades ago with short lower level. After all these years foundation walls and footings deteriorate quite a bit and we need to make sure it’s reinforced during process.

   It’s not uncommon to experience parts of wall falling and crumbling during excavation under, and underpinning contractors need to make sure it is safe to continue work.

7. Underground Water

   There are ways to check if there is water under existing slab in the basement, but most home owners want to start benching and foundation underpinning without spending money on this.

   It becomes difficult to excavate further and pour concrete if underground water actually exists. We need to either dewater entire area of basement or continuously pump water while digging and put extra sump pumps to dispose it later on.

8. Incorrect Drawings

   Construction companies in Ontario proceed work based on approved by city architectural drawings. However, we often see that measurements are of actual basement do not match drawings. Architects have to guess some times exact thickness of the walls and other details.

   Therefore ALBO Renovations has to be extremely careful in such projects and improvise on the spot if minor variance is needed. Bigger drawings deficiencies need to be reviewed by structural engineer.