1,200+ reviews · 4.8★ on Google Licensed & insured · CSLB #1030917
Serving Fresno, Clovis, Visalia, Sacramento and Bakersfield.
Free for homeowners. $299 for real estate transaction inspections.
- FreeLeak diagnosis
with video - Same dayEstimates on
most jobs - Roof + atticBoth sides of
the problem - $800+Most single-issue
repairs
- Moisture meters and thermal imaging, not guesswork
- Emergency temporary repairs if water is coming in now
Tell us where it’s leaking
Two minutes, three questions. We’ll route you to the nearest crew and come find it.
Free · No obligation · We route you to the nearest crew
One we diagnosed
A $100,000 stucco bid that turned out to be the gutters
A commercial building had water getting in. A stucco company looked at it, decided the wall system was the problem, and bid a hundred thousand dollars to tear into it.
We went out and inspected before anyone opened a wall. The gutters were the issue — water was pooling and backing up at that point instead of draining away, and it was getting in from there. Not the stucco. The drainage.
Nobody in that story was lying. The stucco company looked at a wall with water damage and diagnosed a wall. They just never asked where the water was coming from before it reached the wall.
That’s the whole difference between finding a leak and finding damage.
Why it’s hard
The stain is where it landed, not where it got in
Water comes in at a failure, then travels. It runs along the underside of the underlayment, down a rafter, across the top of a ceiling, and drops through wherever it finds a gap. That can be a long way from where it started, and it can be on a different part of the house entirely.
Which is why patching directly above a stain so often fails. It seals a spot that was never leaking, the homeowner pays, and it rains again in March.
Age tells you very little on its own. The sheathing in that photo is stamped 2013 — a roof barely a decade old with a soaked valley, because something was detailed wrong from the start rather than worn out.
It also means a leak that only shows up sometimes isn’t mysterious. Wind-driven rain gets in at angles that ordinary rain doesn’t. A blocked valley only overflows when there’s enough water. A pipe boot that’s split leaks in a downpour and not a drizzle.
How we find it
Both sides of the roof, then the instruments
The attic
Half the evidence is underneath, and you have never seen it. Staining on the sheathing, wet or matted insulation, rot, daylight where there shouldn’t be any, and the trail water leaves as it runs. This is the step most inspections skip.
The roof
Then we work the surface above wherever the evidence points — valleys, flashings, penetrations, and under the tile where the underlayment does the actual waterproofing.
Moisture meters
Wet materials read differently than dry ones. Meters let us map how far the water has traveled and work backwards to where it entered, rather than guessing from the stain.
Thermal imaging
Trapped moisture holds temperature differently from the material around it. A thermal camera shows the shape of a wet area through a surface that looks perfectly normal to the eye.
Experience
Thirty years of trade experience is the part no instrument replaces. Knowing that this era of tract home fails at the valleys, that solar mounts leak in a pattern, that a patio tie-in is where the last guy cut a corner.
Recorded, then shown to you
Everything we find is on video. You watch it with us before anyone talks about price, so the diagnosis isn’t something you have to take on faith.
Then what
Diagnosis is this page. Repair is the next one.
Once we know where the water is getting in, the fix is usually smaller than people expect. Most single-issue repairs — one flashing, one valley, one penetration — land at $800–$1,500. Larger work across several areas runs $2,000–$4,500.
What we don’t do is quote a repair before we know what’s wrong, and we don’t quote a replacement because it’s the easier sale.
What roof repair costs and what we actually fix →
Sometimes the honest answer after a diagnosis is that patching has stopped making sense — when there’s nothing sound left to seal against, or when the deck or framing has gone. Then it’s a replacement, or on a tile roof a lift and relay that keeps your tile. We’ll show you why on video before we say it.
Right now
If water is coming in today
Say so when you book. That moves you up the schedule, and we’ll do an emergency temporary repair to stop the damage while the real repair gets scheduled properly.
In the meantime: move what you can out of the way, put something under the drip, and if the ceiling is bulging with trapped water, a small hole in the low point drains it in a controlled way instead of letting the whole thing come down. Don’t go up on a wet roof to look.
We estimate same day on most jobs, and calls are answered around the clock in English and Spanish.
Verified reviews
What diagnosis looks like from the other side
1,000+ verified Google reviews across four California markets at 4.8 stars. Read them all →
“We had three different roofing companies visit… Two visited both the attic and the roof and one just looked at the roof. Eduardo visited the roof and attic and discovered issues that the other two did not… his video was proof of a wider problem.”
“After having repeat issues with the previous roofing contractor, we reached out to Grandmark… the diagnosis and solution were better.”
“Found out our slopes/valleys were compromised along with 25 other roofing tiles that were cracked or completely broken… They lifted tiles and found the compromised areas that were going to soon cause major problems and water damage.”
Related
Once you know what’s wrong
Straight answers
Frequently asked questions
Do you charge to find the leak?
Not for homeowners. The diagnostic inspection is free with no obligation, and you keep the video whether or not you hire us. The one exception is an inspection for a real estate transaction, which is $299.
My leak only happens sometimes. Can you still find it?
Usually, and an intermittent leak is often more informative than a constant one. If it only leaks in wind-driven rain, that points at a different failure than one that leaks in any downpour. Tell us exactly when it happens — that detail narrows it down before we’re on the roof.
Another roofer already patched it and it’s still leaking.
Common, and usually because the patch went above the stain rather than above the failure. We start over from the diagnosis rather than assuming the previous work was in the right place.
Do you go in the attic?
Yes, when there’s access. It’s where half the evidence lives, and skipping it is the single most common reason a leak gets misdiagnosed.
What if the leak isn’t the roof?
Then we tell you. Water gets in through walls, windows, siding and drainage as well as roofs — the gutter job above is exactly that. We’d rather send you to the right trade than sell you roofing you don’t need.
Find the leak first. Everything else follows from that.
Free diagnosis, video proof, and a written flat-rate price for the repair your roof actually needs.