Diamond Home Services logo
Diamond Home ServicesServing Toronto & the GTA
24 HOUR RESPONSE GUARANTEED

Roof Waterproofing in Grandview, Markham

Professional roof waterproofing in Grandview, Markham — 24 hour response, licensed & insured.

Call (437) 475-2233
24 hour response
Licensed & insured
OEM parts on the truck

Flat and low-slope roofs in Grandview, Markham need real waterproofing, not shingles. We install and service modified-bitumen, EPDM, and TPO membrane systems, seal every seam and penetration, and pressure-test the finished surface.

Why roof waterproofing matters in Grandview, Markham

Flat Roofs Are Different

Shingles rely on gravity. Flat roofs rely on a continuous waterproof membrane — a totally different install skill set.

Seams Are Everything

80% of flat-roof failures are at seams. Torch-welded or heat-welded seams properly executed are what separates a 5-year roof from a 25-year roof.

Drainage Design

Ponding water on a flat roof accelerates membrane failure. We correct slope and drain sizing before laying new material.

Our roof waterproofing process

  1. 1

    On-Site Assessment

    We walk the exterior in Grandview, Markham, document current condition with photos, and identify every failure point before quoting.

  2. 2

    Written Quote

    You get an itemized estimate — parts, labour, timeline — before any work starts. No surprises.

  3. 3

    Professional Repair

    Our crews use manufacturer-approved materials and industry-standard techniques. Every job is fully insured.

  4. 4

    Cleanup & Verify

    We haul away debris, sweep the work area, and walk the finished job with you before signing off.

  5. 5

    Warranty

    Every job in Grandview, Markham carries a written labour warranty and full manufacturer coverage on materials.

Common findings in Grandview, Markham

  • Split modified-bitumen seams over time
  • Failed rubber boots at plumbing vents
  • Ponding water at scupper drains
  • UV-cracked coatings on older systems

What you get

Real Craftsmanship

Experienced tradespeople in Grandview, Markham — not day labour — on every job.

Fair, Upfront Pricing

Written quotes before we start. No day-of surprises.

Peace Of Mind

Licensed, insured, and warrantied. If something isn't right, we come back.

Roof Waterproofing reviews in Grandview, Markham

4.9 average from 743 verified customer reviews
Bundled two services, saved the trip fee
Had the chimney and the dryer vent done on the same visit. Cheaper and half the disruption.
Farah N. - Markham - 2025-12-27
Reliable across three jobs
Used them for a sweep, a dryer vent, and a fireplace service. Same standard every time and the same technician twice, which I appreciated.
Helena B. - Toronto - 2026-04-17
Documentation on everything
Photos, readings, and a written summary after every visit. Makes it easy to keep records for the house file.
Doug T. - Burlington - 2026-01-11
A real person answers the phone
No call centre, no chasing. Booked in two minutes and got a text when the truck was on the way.
Ryan K. - Mississauga - 2026-02-28

FAQ

How long do flat roofs last?

Modified bitumen 20–25 years; EPDM 25–30 years; TPO 20 years. Membrane thickness and seam quality drive longevity.

Can you coat over an existing membrane?

Sometimes — depends on age and condition. We evaluate before quoting.

Do you handle green roofs?

Not currently.

Book your roof waterproofing today

24 HOUR RESPONSE GUARANTEED — call now to lock in a slot in Grandview, Markham.

Call (437) 475-2233

More Markham services

Related pages

Roof Waterproofing in other Markham neighborhoods