How to Find a Roof Leak From Inside a Scottsdale House
The stain is never under the leak. On a tile roof the water gets through the underlayment, runs down the deck or along a batten, and drops at the first nail or seam it meets. On a foam roof it travels along the deck until it finds a seam in the drywall. By the time it shows on the ceiling in a bedroom in McCormick Ranch it may have entered the roof ten feet uphill. Here is how to narrow it down before a roofer arrives, and how far you should take it yourself.
Start with when it leaks
This tells you more than anything else in Scottsdale.
Only in monsoon storms, July to September. Wind-driven rain is getting under the tile from the side and the underlayment is not stopping it. That is a felt problem, and usually an age problem. If the roof is over 15 years old, expect the fix to be bigger than a patch.
Any rain, including gentle winter rain. Something is open to the sky: a cracked tile over a batten, a split pipe jack, a hole in a foam roof, stucco pulled away from a wall flashing. This is a specific defect and usually a $300–$1,500 repair.
Only after a long rain. Slow-path leak. Water is pooling somewhere — a blocked valley, a foam roof scupper that is half-choked, a cricket behind a chimney — and getting in once the level rises.
Right after someone was on the roof. AC service, satellite install, painting, a solar survey. Broken tile from foot traffic is a very common cause of a new leak on a Scottsdale roof that was fine last year.
Not raining at all. It is the AC. A condensate drain line from the air handler in the attic is clogged, or the secondary pan is overflowing. This is common in summer and it is the first thing to rule out.
Then read the stain
- A ring stain that grows with each storm: intermittent leak, the ring is the evaporation line. The source is uphill, on the roof slope above it.
- A stain along a straight line: water tracking a truss or rafter. Follow the line uphill.
- A stain at a wall-to-ceiling corner: wall flashing, or a parapet on a flat roof section.
- A stain around a ceiling fixture or vent: often a plumbing vent pipe jack directly above, or an attic fan.
- Water at a window head on an exterior wall: often not the roof at all, but the stucco above the window or the roof-to-wall flashing a few feet up.
Into the attic
Most Scottsdale homes have a hatch in a closet or the garage. Go up on a bright day with a flashlight, and take a photo of anything you find.
- Look for daylight at pipe penetrations, around the chimney and along the ridge. Daylight at a pipe means a failed jack.
- Look for dark streaks on the underside of the deck. Follow them uphill to the highest point of staining; that is close to the entry.
- Check the insulation for wet, compressed or discolored patches. The wet patch is where water dropped, which is downhill of where it entered.
- Check the AC. Air handler in the attic, drain pan, condensate line. If the pan has water in it, stop looking at the roof.
- Check the ductwork for sweating in summer; condensation off cold ducts drips onto drywall and looks exactly like a roof leak.
Do not walk on drywall. Stay on the joists or the catwalk. And in July and August, an attic in Scottsdale is 140°F or more — ten minutes, early morning, water in hand.
From the roof, or not
If you are comfortable on a ladder and the roof is a low-pitch tile or a flat foam roof, look from the eave without stepping on the tile:
- Cracked, slipped or missing tile, especially uphill from the stain
- Valleys full of palo verde and mesquite debris
- Pipe jacks with split lead or crumbled rubber
- Stucco cracked or gapped where a wall meets the roof
- On foam: scuppers blocked, ponding water, blisters, cracks at the parapet
- Rake and eave tile lifted or stacked by wind
Do not walk a tile roof to find a leak. You will make a second one. Foot traffic on concrete tile breaks it, and on clay it breaks it faster. Roofers walk tile a certain way, on the lower third of each tile where it is supported, and it still costs breakage. A drone or a pair of binoculars from the yard gets you most of what you need.
The hose test, for specific defects
On a dry day with a helper inside, run a garden hose (no nozzle, gentle flow) on the roof starting at the lowest point below the suspected entry and working uphill in stages of a few feet, waiting five minutes at each. When the helper sees water, the entry is within the last stage. This works well on shingle and foam roofs and on specific tile details like a pipe jack or a wall flashing. It does not reproduce a monsoon leak, because a hose does not blow rain sideways under the tile.
Mistakes that make a leak harder to find
- Caulking from below. Sealant on the ceiling side does nothing to the water path, and it hides the stain the roofer needs to read.
- Walking the roof to look. Covered above, but worth repeating: on tile, it makes a second leak.
- Painting over the stain right away. Wait until the source is fixed and the drywall has dried, or the stain bleeds back through and you lose track of whether it is old or new.
- Assuming it is the roof. AC condensate, a loose water heater flue cap and a cracked shower pan above a ceiling can all look like a roof leak.
- Waiting for the next storm. A small drip that dries out in a day still wets the deck, and the deck pays for every storm.
What to tell the roofer
When you request an estimate, give the date and time it leaked, what the weather was doing (wind, steady rain, or nothing at all), where the stain is in the room, and whether you found anything in the attic. Send the photos ahead if you can. A roofer who knows the leak only showed up in a southwest wind will lift tile on that slope first, which saves time on the roof and usually saves you money.
Common questions
Can a roof leak show up months after the storm?
Yes. Water can sit in insulation or run along the deck a long way before it reaches drywall, so a stain in October can come from an August storm. Check the attic for the full path.
Should I cut into the ceiling to find the leak?
Only a small drain hole into a bucket if the drywall is bulging with water. Otherwise leave the ceiling alone until the source is fixed, then have the wet section checked and repaired.
What you have when you are done
A photo of the stain, a note on when it leaks, and if you went into the attic, a photo of the highest staining and whether the AC pan is dry. That is enough for a roofer to arrive knowing where to lift tile. The repair page covers what the common causes cost, and if the answer turns out to be failed felt everywhere, repair vs. replacement is the next read. If the water is coming in now and it is still raining, catch it, punch a small hole in the bulging drywall so it drains into a bucket instead of spreading, and call a roofer. Say that water is coming in now, and ask how soon someone can come out.
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