So, you have a damaged foundation, renovating your basement or are looking to add stories to your existing home In Toronto; the only solution is – underpinning. When a building is being enlarged or is converted for use in a new type of activity; you have to prepare it for heavier loading than it was designed for.
If a new building with relatively large and deep foundations and basements is being constructed being proximity to your house; you probably have to undergo foundation underpinning to avoid problems of a sinking foundation in the future.
On the similar lines, if there are cracks in the walls near windows and doorways, or you’re experiencing sinking and sloping floors, these may be early indicators that something wrong is going on with your home’s foundations.
In almost all of the underpinning cases, excavation is a prerequisite, which is labor-intensive work and a messy thing overall for the homeowner. But with apt planning and following the correct underpinning procedures one can strengthen a building’s foundation and avoid major setbacks that are irreversible in some cases.
Anyhow, here are we with this thorough guide on how you can undertake foundation pinning in the right manner and avoid pitfalls while doing so. The read will also guide you on how a reputable contractor can help you undertake these works flawlessly and without a hassle.
Feeling intrigued? Let’s jump straight in
Correct Underpinning Procedures
There are several underpinning methods and knowing the correct method and procedure, one must fully understand the current situation and problems concerning the foundation of the building. Depending on the type of foundation of your home; you might only have to go with a single method that will be suitable. Anyhow, you have to keep in mind the factors causing damage to the existing foundation, depth of excavation, cost and time involved along with local permits and regulations.
In most of the cases three methods are used:
- Mass Pouring
- Beam and Base Method
- Pile Method
If you’re looking for a low cost and simple solution that doesn’t involve too much digging, then the mass concrete method is a must pick. It is the most common and traditional method that is best suited for the shallow foundation. It involves simply excavating the weak soil underneath the foundation and replaces it with the concrete of suitable strength.
If you’re to apply relatively heavier loads on the structure than you can use the beams, constructed below, above or in place of the existing foundation, to evenly spread the loading on the mass concrete base. This method is termed as beam and base method. The size and position of the beam have to be decided depending on the architecture of the structure, type of foundation, and type of loading applied.
If your foundation is on the clayey soil or the area is waterlogged than the pile method is recommended by the most general contractor. You can also go for this method due to space restraints when you have limited access to the construction site. They drive the piles at equal distance along the wall and it helps in relieving the load of the existing foundation. In some cases, the piles are steel-cased that are afterward filled with concrete.
What can go wrong during underpinning?
It is of no doubt that underpinning prevents structural collapse but it is only after you’ve completed the procedures but what about the process? Things can go wrong in seconds and if not done well you are risking your entire property.
Underpinning involves the danger of collapse and accidents if proper shoring and temporary supports are not provided to the existing structure. A detailed site investigation has to be taken up considering even your neighboring houses. The underpinning design must incorporate a detailed and analyzed report of project premises. Any risks to the adjoining structures must be ascertained to avoid collapse during or after construction.
Qualified underpinning contractors always recommend reducing the imposed loads on the structure. This can prevent accidents and collapse during excavation for foundation underpinning.
Cost & Time
“How much foundation underpinning cost for my house?” This is the most common question homeowners generally ask us. Well, there is not a sure-short answer to this question. Evaluating the time and cost of underpinning project require a detailed assessment of the existing foundation and condition of the existing structure.
One has to determine the required excavation levels, footing arrangements, plans and details for moving or extending load-bearing walls, the extent of excavation involved, and the amount of concrete required.
Underpinning is a complex and costly process that might be disruptive for everyone in the house, but the return on investment is substantial. It isn’t a job for armatures and it has to be handled by licensed pros.
Just to give you a hint, most foundation footing and underpinning repairs can cost anywhere from $350 to $480 per linear foot of foundation wall. This cost depends directly on the type of footing the structure requires and the number of pins required based on the extent of work. So, for a wall of 10 feet, you require a budget of $3500 to $4800. For calculating the exact cost of foundation underpinning, specialist requires to evaluate your home and determine the size of work required.
For extending and lowering the basement, the underpinning costs about $80 per square foot and the average cost to excavate for lowering the basement is approximately $400 per linear foot. While the cost for the service of an architect to complete drawings and obtain a permit for basement lowering is about $2500 to $4500.
The timescale for acquiring the permits from authorities is 25 to 30 days but it will vary depending on the difficulty of the drawings and the time of year you’re acquiring the permit. The actual timescale per job is typically 25 or more days depending on the extent of work and complexity of the site situation.
Importance of Reputable Contractor
Underpinning your existing home is a whole lot of investment, it is a big tool against subsidence, and is the game-changer. But it can be very expensive and can make a mess of your home if done badly due to the shoddy workmanship of a poor contractor.
When it comes to underpinning, Self Build Canada is a licensed and insured contractor and our 5-star construction services are second to none. As a competent contractor, we’ll accurately identify the structural repairs required for your foundation and will advise you on the correct solution. As an experienced contractor, you never have to worry about the permits as we’ll handle every bit of a job for you.