Built on Diagnosis, Not Guesswork
MC&J Waterproofing Company Inc keeps water out of Bay Area buildings — foundations, basements, decks, planters, and floors — by finding the real source before specifying a single product.
A waterproofing crew that treats the cause
MC&J Waterproofing Company Inc installs waterproofing, deck coating, and epoxy floor systems for residential and commercial property across the San Francisco Bay Area & the Peninsula. We work on single-family basements and garage floors, on estate planters and subterranean garages, and on podium decks and parking structures for multi-family and mixed-use buildings.
A large share of our work begins as somebody else's repair that did not hold. The pattern is almost always the same: the coating was applied to the place the stain appeared rather than the place the water entered, or the surface was never prepared properly, or a membrane went on with no drainage behind it. Those are not product failures. They are process failures.
So we start with diagnosis every time — electronic leak detection, moisture mapping, controlled water testing — and only then specify a system matched to the substrate, the exposure, and the water pressure involved. Sometimes that means a smaller job than the customer expected. We would rather say so than sell the larger one.
Every project comes with a written scope, a realistic timeline, testing before close-out, and photo documentation of what we found and what we fixed. Estimates are free across our entire 60-mile service radius.
What we stand for
Six standards we hold ourselves to on every project, from a single crack injection to a full parking deck.
Diagnosis First
We establish where water is entering before we specify anything. Guessing is how repairs get repeated.
System Over Product
Membrane, drainage, and detailing work together. A membrane with nowhere for water to go is half a system.
Preparation Discipline
Grinding, profiling, moisture testing. The unglamorous half of the job decides how long the finished work lasts.
Plain Communication
Written scope, honest timelines, and a straight answer when the cheaper option is the right one.
Verified Work
Flood tests, electronic detection, and photo records — proof rather than assurance.
Responsive Service
Estimates answered the same business day, and crews that arrive when the schedule says they will.
A better service experience, by design
Generic promises are easy to make. These are the specific habits that change the outcome on a job site.
Four steps from first call to sign-off
A predictable process, so you always know what happens next.
Consultation
You describe the symptom. We ask when it appears, how fast, and what changed — the details that narrow the source.
Diagnosis
Inspection, moisture mapping, and controlled water testing where needed, to isolate the real entry point.
Installation
Surfaces prepared, system installed to spec thickness, detailing reinforced at every joint and penetration.
Verification
Tested under real conditions, documented with photos, and walked through with you before close-out.
Local crews across the Peninsula and South Bay
We cover twelve cities within a 60-mile radius, from San Francisco through to San Jose — with the same standards on every one.
Ready to work with a crew that finds the source?
Get a free, no-pressure estimate and see what a diagnosis-first process looks like.