Two hard tests: sun, then storms
Most of the year, an Arizona building’s enemy is heat. Roof surfaces in direct summer sun run far hotter than the air, and the daily swing from afternoon heat to night cooling makes materials expand and contract again and again. Ultraviolet light breaks down sealants, coatings, membranes, and plastics, so many materials age noticeably faster than they would in a milder climate.
Then come the storms. The National Weather Service treats June 15 through September 30 as Arizona’s monsoon season, and the storms within it can drop heavy, wind-driven rain in under an hour. A roof, window, or wall that has been dry for months is suddenly asked to shed a large volume of water sideways, often after heat has already opened small gaps.
This article explains, in general terms, how these conditions expose construction defects and what an investigation looks at. We take construction defect and expert witness matters anywhere in Arizona, and Gregg de Haan holds an Arizona KB-1 Dual Building Contractor license, ROC341972.
Roofs: tile, foam, and low-slope membranes
Concrete and clay tile roofs are common across Arizona. The tile sheds most of the water and shades the roof, but the underlayment beneath it is what keeps water out of the building. When underlayment is too light or under-specified, poorly lapped, or poorly flashed at valleys, walls, and penetrations, a tile roof can leak while the tile itself looks fine.
Many low-slope roofs use sprayed polyurethane foam, built-up membranes, or single-ply membranes. Foam depends on a protective coating to resist sun damage, and that coating needs periodic renewal. Low-slope roofs also depend on drainage: ponding water, undersized or blocked scuppers, and drains set too high all show up quickly in a monsoon downpour.
Parapet walls deserve particular attention. Their caps, corners, and the joint where the roof meets the wall are frequent leak paths, and water entering there can travel inside the wall a long way before it appears. Roofing and sheet metal is one of our investigative specialties.
- Underlayment beneath tile: laps, valleys, wall and penetration flashings
- Foam roof coatings, ponding, and blistering
- Scuppers, drains, and overflow capacity
- Parapet caps, corners, and roof-to-wall transitions
Stucco and the water behind it
Cement plaster, usually called stucco, over wood framing is one of the most common wall systems in Arizona. Fine cracks in stucco are common and are not always a defect. The more important questions are often behind the plaster: whether the water-resistive barrier was lapped correctly, whether window and door flashings were integrated with it, and whether water that gets behind the stucco can drain out at the weep screed.
When those details fail, water that enters during a monsoon storm can soak framing and sheathing with little sign on the surface. Staining below windows, efflorescence, cracking that follows framing lines, and soft or bulging plaster can all point to water behind the wall.
Our investigative specialties include cement plaster, wood siding, and composite siding, along with waterproofing and building paper installation and windows and doors. Those are the assemblies that decide whether a stucco wall stays dry.
Windows, doors, and wind-driven rain
Monsoon rain often arrives sideways. Windows and doors that perform in calm rain can leak when wind pushes water against them, especially at corners, sill pans, and the joints between the frame and the wall.
Separating a product failure from an installation failure matters, because it can point to different responsible parties and different repairs. Our investigative specialties include windows and doors, including product and installation water testing. Field water testing can simulate wind-driven rain under controlled conditions and help trace the path water takes.
Soils, slabs, and site drainage
Parts of Arizona have expansive clay soils, which swell when wet and shrink as they dry and can move slabs, footings, and flatwork. Others have caliche, a hardened calcium carbonate layer that can keep water from draining down, so water lingers near foundations. Both make grading and drainage more important.
Monsoon runoff tests that grading quickly. Water that is directed toward a foundation, trapped against a wall, or left to pond near a slab can cause damage that shows up as cracked slabs, heaved flatwork, or moisture at the base of walls. Not every crack is a defect, though: concrete shrinks as it dries, and an investigation separates expected cracking from movement that points to a problem. Site drainage and concrete are both among our investigative specialties.
The high country is a different climate
Flagstaff, Prescott, and Arizona’s other higher-elevation communities have real winters. Roofs and decks there face snow loads, ice at the eaves, and freeze-thaw cycles that desert construction does not.
We are snow country building specialists, and Gregg de Haan specializes in high alpine waterproofing, roofing, and general construction. A matter in the high country calls for the same attention to snow and ice that a mountain building anywhere does.
Codes and timing in Arizona
Arizona has no general statewide building code. Cities, towns, and counties adopt and amend their own, usually based on the International Code Council’s model codes, so the code that governed a building depends on where and when it was permitted. Identifying that code is an early step in any code compliance review.
Arizona’s statute of repose generally bars contract and implied warranty actions against those who designed or built an improvement to real property more than eight years after substantial completion, with up to nine years when the property is injured or a latent defect is discovered in the eighth year (A.R.S. § 12-552). For homes, the Purchaser Dwelling Actions statutes require written notice of the claimed defects to the seller, by certified mail, before a suit is filed; the seller may inspect and has 60 days to respond (A.R.S. § 12-1363).
Both rules turn on dates and documented conditions, so early documentation matters. Shorter statutes of limitations can end a claim sooner. This is general information, not legal advice; counsel determines how these rules apply to a particular matter.
What an investigation looks at
An investigation starts in the field. Our field personnel identify and document defects promptly, and we use camera and video documentation techniques to provide trial-ready exhibits. Water testing traces leaks to their source, and we take field samples to store at our office in case they are needed at trial.
Where a material appears to have a manufacturing defect, we are aligned with several laboratories that test and analyze product failure. Findings are organized into comprehensive field reports, photo documentation, conceptual repair scopes, and cost estimates, and we provide expert witness services for settlement conferences, mediations, arbitrations, depositions, and trial.