Internal Waterproofing
Comprehensive sub-slab drainage systems and sump pumps that keep lowered basements dry permanently.
Internal Waterproofing
Comprehensive sub-slab drainage systems and sump pumps that keep lowered basements dry permanently.
Lowering a basement puts your finished floor deeper into the water table, so drainage is not an upgrade — it is part of the structure. Older Toronto homes with clay soil, original weeping tile, and 140-year-old masonry are particularly vulnerable to hydrostatic pressure once the slab drops.
We install the waterproofing system as part of the same excavation: dimpled membrane against the walls, new weeping tile bedded in clear gravel below the slab, and a sump system sized for the volume your lot actually produces. Every component is tied together before the new slab is poured, so nothing is retrofitted later.
How We Help
- Heavy-duty dimpled drainage membrane installation along basement walls
- Sub-slab interior weeping tile and gravel trench drainage
- High-capacity sump pump systems with dual battery backups
- Complete moisture barrier sealing to prevent dampness and mold
Our 4-Step Structural Process
We assess your foundation, soil, and load paths on site, then engage our structural engineer.
Stamped drawings and City of Toronto permits are handled end to end before a shovel moves.
Pin-by-pin excavation and reinforced concrete pours keep the structure fully supported throughout.
Engineer and municipal inspections, cleanup, and a written workmanship guarantee.
What Toronto Homeowners Say
Ken's crew lowered our 1890s Cabbagetown basement by three feet. Meticulous sequencing, permits handled, and our heritage brick came through untouched.
Reliable & Trusted Underpinning
Built Around Your Schedule
We protect the value of your property with full coverage, dedicated in-house crews, and guaranteed work.
WHY WORK WITH GTA UNDERPINNING:
- Dedicated In-House Crews
- Flexible Scheduling
- Heritage Home Experts (140+ Yrs)
- Fully Insured & Bonded
- WSIB Good Standing
- 200+ Jobs Completed
Trusted Across the Greater Toronto Area
Start With A Free Structural Consultation
Book a free, no-obligation on-site inspection today.