A formed concrete foundation wall
Structural basement lowering — Mississauga

Lower the floor. Keep the room.

Underpinning rebuilds the foundation beneath your house a few feet at a time. The floor drops, the walls stay, and you lose nothing off the finished room.

  • Answering 24/7
  • Engineered drawings on every job
  • Permit and inspections
  • Mississauga and the west GTA
  • 4 ftMax section widthThe wall is never opened wider than this at one time.
  • 1 in 3Open at onceTwo thirds of the wall is always carrying the house.
  • 0"Floor area lostUnderpinning takes nothing off the finished room.
  • 8StagesFrom the first measurement to the final inspection.
01 — Services

What we do below the floor

Six things, all structural, all in and around Mississauga.

02 — Signs

Is this your basement?

Any one of these is a reason to measure before you plan anything else.

You cannot stand up comfortably

Six and a half to seven feet slab-to-joist is normal in older Mississauga houses.

Ducts and beams hang below the joists

The lowest thing in the room is what really sets your ceiling height.

You are planning a second unit

Ceiling height is the requirement a low basement fails first.

A wall has cracked or a footing has settled

Underpinning is also the repair when the ground below will not carry the footing.

The floor is damp after heavy rain

A lowered floor needs drainage designed for the new depth, not the old one.

There is no separate way in or out

A walkout or an egress window is cut while the basement is already open.

A raw concrete basement room with daylight falling down the stairs
What we hand back

A bare, level, drained concrete floor

Drainage in, sump running, inspections signed off. Nothing left for the next trade to guess at.

03 — Method

Why digging under a house does not drop the house

Existing foundation wall — carries the houseExisting footingUndisturbed soil at the new bearing level1231231231 — poured and cured2 — open right now3 — not yet touched
Fig. 1 — one wall, nine sections, three rounds1 is poured and cured. 2 is open right now. 3 has not been touched.
Underpinning

Keeps the whole room

  • New concrete below the existing footing
  • Floor area unchanged
  • Flat walls to the floor
  • Costs more, takes longer
Bench footing

Costs less, takes a strip

  • Nothing goes below the footing
  • A permanent ledge on every wall
  • Less floor in the finished room
  • Cheaper, faster on site

Full comparison

04 — Process

Four stages, in this order

  1. Step 01

    Measure

    Slab to joist in several places, the wall type, and how material gets in and out.

  2. Step 02

    Drawings and permit

    A designer prepares the structural drawings; the permit goes in with them.

  3. Step 03

    Underpin in sequence

    Numbered sections dug, formed and poured, with curing time between rounds.

  4. Step 04

    Drainage and slab

    Weeping tile to a sump pit, then the new floor — inspected and handed over.

All eight stages in detail

05 — Why homeowners call us

How the work is actually run

Drawn and permitted

Section widths, order and depth come off a stamped drawing, not off a shovel.

Never left unsupported

Only non-adjacent sections are open, so the footing always spans solid ground.

Drainage is part of the structure

Weeping tile, stone, vapour barrier and a sump pit go in before the slab.

Curing time in the schedule

Concrete gets the days it needs. A plan without them is not being followed.

Your house is protected

Dust separation and a protected route before anything is broken out.

One trade, one crew

Excavation, concrete, drainage and wall openings are the same job to us.

06 — Gallery

What the floor becomes

The structural work ends at bare concrete. This is what gets built on it.

07 — Reviews

What people in Mississauga say

5 out of 5 from 11 Google reviews

★★★★★

The thought of excavating beneath our home in Mississauga terrified me at first, but the team at Basement Underpinning put all our anxieties to rest immediately. Their senior estimator provided a transparent, itemized quote with zero hidden fees and walked us through the engineering physics behind how underpinning actually protects a home's foundation. The on-site crew was meticulous, setting up laser levels and shoring posts to ensure the house remained completely stable throughout the multi-week excavation. They poured solid concrete benches, installed a high-capacity sump pump, and left our basement completely clean. Our home is structurally sound, our ceilings are high, and the added living space has dramatically increased our property value.

escortcykaPosted on Google
★★★★★

Our 1960s split-level home in Mississauga had a portion of the basement that was dangerously low, making walking upright impossible for anyone over five feet tall. Basement Underpinning evaluated the unique multi-level foundation layout and crafted a brilliant underpinning and excavation strategy. They systematically lowered the sub-floor area, poured deep concrete underpinning pins, and integrated a complete perimeter weeping tile system to eliminate any historical moisture risks. The workers were courteous, worked tirelessly through long shifts, and ensured our structural stability was never compromised for a single second. We now have full ceiling height throughout the entire lower level, doubling our functional living space. Absolutely top-tier work!

Nazar MerchanskyiPosted on Google
★★★★★

Working with Basement Underpinning on our complex foundation lowering project in Mississauga was an absolute masterclass in professional contracting. Our home had unique soil conditions and a shallow original footing that required custom bench underpinning and structural steel reinforcement. Their crew showed up every morning ready to tackle heavy labor with positive attitudes and unmatched skill. They kept our property tidy, used heavy protective coverings over our pathways, and completed the structural phase ahead of schedule. The peace of mind that comes with knowing our house is resting on deep, reinforced concrete pins is priceless. An extraordinary team of experts who genuinely care about structural quality and customer satisfaction!

MattPosted on Google
★★★★★

Undertaking a basement underpinning project in a tightly packed Mississauga suburb requires incredible logistical skill, and Basement Underpinning executed our project with military precision. From the initial architectural drawing reviews to the final municipal inspection sign-off, their team managed every single detail seamlessly. They lowered our basement floor by two and a half feet, poured a brand-new reinforced concrete slab with radiant in-floor heating rough-ins, and installed a commercial-grade sump pump system. The crew leaders were communicative, friendly, and always available to answer questions about the structural phases. Our dark, unusable basement is now a gorgeous, bright family room. I cannot recommend their underpinning expertise enough to local homeowners.

MykolaPosted on Google
★★★★★

We had a vision of converting our unfinished Mississauga basement into a legal rental apartment, but the low ceiling height was a major legal roadblock. Basement Underpinning stepped in and provided a turnkey structural lowering solution that solved our problem completely. They used advanced underpinning methods to drop the floor level safely without compromising our home's foundation walls. Their team coordinated all the structural engineering permits, managed the soil disposal bins efficiently in our driveway, and completed the concrete pours on an aggressive timeline. The quality of the finished concrete floor is exceptionally smooth and level, ready for luxury vinyl flooring. Their professionalism, transparency with pricing, and structural knowledge are second to none.

xan 123Posted on Google
★★★★★

Our Mississauga home had a chronic dampness problem alongside very limited headroom, making the lower level little more than a dusty storage zone. We hired Basement Underpinning to perform a full bench underpinning and waterproofing project, and the results exceeded our wildest expectations. Their crew arrived equipped with heavy-duty machinery, laser levels, and industrial air scrubbers to keep concrete dust out of our living quarters. They excavated the perimeter systematically, poured solid concrete benches that doubled as structural stabilization, and installed a state-of-the-art interior drainage system. The transformation in structural safety and usable square footage is staggering. If you want a company that takes structural integrity seriously and delivers immaculate work, look no further.

Elina SkrybkaPosted on Google

Read all 11 reviews

08 — Areas

Where we work

Mississauga first, and the parts of the west GTA close enough that a crew is not sitting in traffic instead of in your basement. The older neighbourhoods are where most of this work is.

Neighbourhood by neighbourhood

  • Cooksville
  • Port Credit
  • Mineola
  • Lakeview
  • Applewood
  • Clarkson
  • Sheridan
  • Erindale
  • Streetsville
  • Lorne Park
  • Malton
  • Rathwood
  • Erin Mills
  • Churchill Meadows
  • Meadowvale
  • Dixie
  • Hurontario
  • City Centre
09 — FAQ

Questions we get every week

How does the house stay up while you dig underneath it?

The wall is divided into short numbered sections and only non-adjacent ones are ever open. The existing footing spans the gap, and each section is poured and cured before its neighbours are touched.

How long does it take?

Weeks rather than days. The curing time between rounds is a large part of that and it cannot be compressed.

What does it cost?

We do not publish a per-foot number. Access to the house and how much depth you are adding move the figure more than the length of the wall does — here are all nine factors.

Do I need a building permit?

Yes. Excavating below a footing is structural work, so it needs drawings from a qualified designer and a permit before anything starts. So does a bench footing.

Can we live in the house during the work?

Usually yes. It is loud and dusty, and the basement itself is unusable from the day the slab comes out until the new one is poured.

What state is the basement in when you finish?

Bare, level, drained concrete with the sump running — ready for the framing trade. Finishing is a separate trade and a separate budget.

All fifteen questions

10 — Reading

Before you sign anything

Start with a measurement, not a quote

Send the height from your floor to the underside of the joists, and what you want the room to become.

CallBook an assessment