Mark Matcho

Callbacks and construction defects have made the national news again. A recent Nightline segment detailed shoddy construction in production homes around the country. The program, replete with teary homeowners, searched out only the most dramatic errors, including one home with melted siding and another with more than 800 drywall nail pops. The intended message was clear: builders are doing low-quality work. Of course, such problems are rare among pros who are serious about great work and great service.

Smart builders will use such reports as an opportunity to differentiate themselves. With homeowner scrutiny on the rise, it’s a good idea to take a second look at what can go wrong on a job. It’s a chance to up your game.

With this in mind, BUILDER asked industry pros around the U.S.—contractors, engineers, consultants, and home inspectors—to share the most common callbacks and defects they see in their markets. Their responses ranged from visible, often minor issues to serious problems that can remain hidden for years before leading to catastrophic failure. What follows are the most cited problems.

Aesthetic Issues

Not surprisingly, most everyone mentioned drywall cracks and nail pops. “These are cosmetic issues, but some people come unglued over them,” says San Bruno, Calif.–based builder Skip Walker. Avoiding them is a matter of paying for good work. “We tried a less expensive drywaller on a few jobs, but those jobs had problems,” Walker adds, noting that the bargain drywaller took shortcuts like skipping coats, not leaving sufficient drying time between coats (mud needs about three days to dry in his area in winter), and using fast-drying “hot mud” that becomes brittle and more prone to cracking.

Pre-drying the framing also helps. “If the house will eventually reach an equilibrium moisture content of 10% but the unconditioned lumber is at 14%, you will get cracks and nail pops as it dries and shrinks,” says Matt Risinger, owner of Austin, Texas–­based Risinger Homes.

Before hanging drywall, he lowers the framing’s moisture content to 12% or so by using fans, dehumidifiers, or the home’s space conditioning system. Then he leaves the heat and air conditioning on while finishing the interior. The approach seems to be catching on in the industry: “The top three or four builders around here are already doing it, and other companies are starting to follow suit,” he says.

Annoying Squeaks

“Subflooring is a big source of callbacks,” says Risinger, noting that the use of commodity OSB makes squeaks inevitable. His advice is to upgrade to 1 ⅛ subfloor like Huber Engineered Wood’s AdvanTech or Georgia-Pacific’s Plytanium Sturd-I-Floor. Should you need further convincing, Risinger says that in 10 years of using engineered subflooring he has had no callbacks regarding that area of construction.

Since these products are polyurethane-based, it’s crucial to use a high-quality polyurethane adhesive, he adds. “Old school glues don’t stick to these products,” he says.

Roof and Sidewall Ripples

Another common problem is sheathing that swells and buckles, telegraphing waves through the cladding. The fix is a simple: leave a ⅛-inch gap between the sheets. A 16d nail will make the proper space over rafters, though you may want to use H-clips over rafter bays.

Some framers seem unaware of this advice. “I hired two guys to help me frame an addition, and neither one had heard of gapping sheathing panels,” notes Chip Kiper, a Leavenworth, Kan.–based builder and remodeler. He now inspects the sheathing before it’s covered. “If any sheets aren’t gapped, I use a saw to make a kerf between them.”

Swelling can also be a problem with fiber cement, where joints between horizontal runs need to be gapped and filled with sealant. “If you ignore this advice, the board will soak up water and swell at the edges,” says Bill Robinson of

Sagging Floors

“I see a lot of framing errors that lead to uneven floors,” says Atlanta structural engineer Chris DeBlois, noting that the problem has to do with the way today’s homes are designed. “In an older Colonial you know the rooms will be stacked with a central bearing wall. No more.”

DeBlois says with today’s open floor plans, some designers forget to account for the loads the floor will likely bear. For instance, he was called in to look at a large kitchen with no bearing wall under the joists (there was a media room directly below it), and an 8x12 island topped with a granite slab. “Whoever did the framing layout didn’t take the weight of that granite into account, so the kitchen floor ended up settling and sloping toward the island, like a little bowl,” he says. The builder had to go back, jack the floor up, and triple the joists. DeBlois has also seen settling in rooms with thickset tile or stone floors.

Hot and Cold Spots

Comfort complaints are rampant, according to our sources, and the fault often lies with the ductwork.

“A lot of residential ducts have excessively high static pressures,” says Jose de la Portilla, technical training manger with HVAC Learning Solutions in the Dallas-Fort Worth area in Texas. “The mechanical equipment has to run longer and has to start and stop more often, making it more prone to breakdown and premature failure.”

The causes behind excessive pressures range from undersized ducts to excessive bends to sagging flex duct. Some installers suggest using rigid fittings for elbows and other directional changes, then stretching runs of flex duct taut between them. Many homes also have inadequate return paths that rely on door undercuts, leaving some rooms too hot and others too cold. The best way to avoid these problems is to consult with the mechanical contractor during the design phase.

Another comfort killer is ducts in unconditioned spaces that aren’t properly insulated or sealed. While this issue has gotten attention, many installers still haven’t gotten the memo. An unsealed supply duct in an unconditioned space can waste as much as 500 cubic feet of air per minute, and leaky return ducts can pull hot or cold outside air into the system.

Damp Basements

“A leaky foundation is the worst callback because it costs so much money to fix,” Risinger says, adding that many homes in his market have water seepage at the slab-to-wall connection. Even without visible water, a damp basement or crawlspace can turn into a mold generator. “Stepping up your game when it comes to foundation waterproofing makes a huge difference,”he says.

He advises against fluid-applied waterproofing membranes because they depend on near-perfect application. “They have to be installed at the right thickness with the right number of coats, and you need to make sure all the conditions for proper

adhesion have been met.” Instead, he uses a peel-and-stick membrane that’s covered with a dimple mat to relieve hydraulic pressure against the foundation, and backfilled with something that encourages drainage to a perimeter drain.

Kiper prefers to put rigid foam insulation against the concrete, covering it with fiberglass resin panels to protect the foam from damage. He caps the assembly with sheet metal to keep termites out of the house.

Kiper also points out that the basement is more likely to stay dry with a sound structure. “Even a hairline crack can let moisture into the wall,” he says. He recommends wide footings with plenty of steel reinforcing over thoroughly compacted soil. After pouring the footing, he also embeds a tapered 2x4 in the concrete to create a key joint, then removes it before pouring the wall. “I know the key joint works because I haven’t had any leaks there,” he says.

Stucco Failures

Getting stucco right seems to be a challenge on a lot of jobs. “It’s the most common problem we see,” according to Richard Baker, builder solutions program manager at IBACOS. Baker and his team perform regular quality control assessments on product jobsites around the country. One problem with stucco is the same as many of the other callbacks in this article: the industry has lost its best craftsmen. “We don’t see the skilled labor that we used to,” Baker says.

Stucco errors fall into three categories, the first being missing joints. The ASTM standards that govern stucco specify control joints every 144 square feet. Ambiguity in how some stucco systems implement these standards and the fact that some builders don’t like the look of control joints means they often get left out. Some installers also forget to put a flexible sealant where the stucco meets another material, such as around a window. The result is the same in both cases: the stucco cracks when it expands, letting water into the structure.

The second big stucco error is the wrong mix: Too much sand can make the mix weak and prone to cracking; too little sand leaves it brittle, so cracking tends to be dramatic. When brittle stucco cracks, “it can sound like a gunshot,” says Baker. He has even seen it shear the metal lath beneath the stucco. The solution to both problems is to use pre-mixed stucco.

The third error stems from poor hydration. Stucco needs to be kept hydrated for a few days after it’s applied. Some installers skip this step, causing the pH to stay too high and making the stucco less able to hold paint. “Some builders compensate by using pH-resistant paints, but this is not a silver bullet,” Baker says. “They really need to hydrate the stucco.”

Mistakes like these aren’t confined to stucco. Contractors also see them with adhered masonry products. “The adhered masonry veneer on every house I see is wrong,” says Cary, N.C.–based home inspector Bruce Barker. “The biggest problems have to do with transitions: missing backer rod or sealant around window jambs, as well as missing weep screeds.”

To avoid such mistakes, builders need to take care when hiring siding subs. They also need tighter specs and to ensure the job superintendent or lead carpenter is on site. “We advise more site supervision on the days stucco is being installed,” says Baker.

Leaky Transitions

With exterior flashings the most problematic spots are where brick veneer meets another type of siding, and where a roof dies into a sidewall.

“At least in my market, a lot of them don’t understand how their trade relates to the other trades,” says Jim Schneider, a custom builder in Norfolk, Va. He has responded with scopes of work that detail exactly how the flashings have to be done, and he makes sure his job supervisor is on site to check the work.

Where a roof meets a wall, the roofer often will neglect to install kickout flashing. The kickout is a bent piece of metal at the base of a step-flashing run that directs water into the gutter. When it’s missing, water can run down the wall below the gutter, finding its way behind the siding and rotting the sheathing.

Some architects and homeowners don’t like the look of kickouts. An alternative (suggested by Bill Rose, author of Water in Buildings: An Architect’s Guide to Moisture and Mold) is to nail a pressure-­treated 2x4 at the roof-wall intersection before installing roofing or siding. Then bend the step flashing over the 2x and down onto the roof. This puts the flashing outboard from the cladding and directs water straight into the gutter.

Penetration Detailing

Installers have gotten better in recent years when it comes to window flashing. The one exception is the sill pan. “All exterior doors and windows need a sill pan, but contractors in general aren’t using them,” says Train2Build’s Robinson. “That’s fine if everything else is perfect, but it rarely is.”

Barker says that aluminum windows especially need a pan because installers can rack them during installation, breaking the seal at the bottom corners. “The IRC doesn’t require pan flashing on windows unless the window manufacturer does, and window manufacturers often don’t,” he explains. By the time the homeowner sees a stain on the wall there is already rot in the structure.

We also heard about leaky pipe and vent penetrations. When someone cuts a hole for a gas line or dryer vent, they need to flash it to the water-resistant barrier. But they seldom do. “I see this done incorrectly all the time,” says Robinson. He says the problem won’t be fixed until installers start taking wall penetrations as seriously as roof penetrations. He also recommends prefabricated boots like those made by QuickFlash.

Robinson adds that the only caulks and sealants used around penetrations should be those with a high solid content like silicone or polyurethane. “Otherwise it will shrink down to its solid content, leaving gaps,” he says.

Flat Roof Leaks

Modern architecture is quite popular in some parts of the country, and modern architecture means flat roofs. “Flat roof problems are common in my market,” says Risinger. “We have to go to crazy extremes to make sure they don’t leak.”

While today’s roofing membranes are durable, it can be hard to integrate the roof and wall flashings. Even the smallest defect can cause a leak. Risinger learned this the hard way after a scupper in a parapet wall at the edge of a flat roof let water into the structure, causing several thousand dollars in damage.

He now uses peel-and-stick or fluid-applied membranes on walls and parapets, and he brings the roofer in early to integrate the membrane with the roof flashing. Following these steps, he hasn’t had a problem since.

Custom Showers

Upgraded master baths with custom showers that feature built-in seats and multiple showerheads are a popular option among well-heeled homeowners. They tend to be on the second floor above a living space, so leak proofing is crucial. But if, as is often the case, the seat is built into a corner or the shower has an L-shape, the waterproofing membrane can be hard to detail correctly.

Baker is seeing more installations with pinhole leaks that are hard to detect, but that let mold and rot slowly build up in framing cavities. “Complex showers need a higher level of waterproofing,” he cautions. For instance, while the membranes beneath most showers aren’t sloped, it’s worth the effort to slope the underlayment in the shower toward the drain before applying the membrane.

Callbacks can be costly. When it comes to serious issues like waterproofing and framing, getting it right the first time is crucial. When it comes to minor annoyances, however, the easiest course for builders may be to schedule a callback ahead of time.

When he closes out a job, Mark Scott, a builder and remodeler in Cabin John, Md., schedules two follow-up quality inspections: one in six months and the other in 12 months.

“During the six-month inspection we look for anything unusual like abnormal settling, and we address those issues within two weeks,” he says. At the 12-month inspection he takes care of all the cosmetic stuff. “We tell the customers that the home needs to go through a heating and cooling cycle in order to reach equilibrium, then we can fix nail pops and such and they will stay fixed.”

Not only has this reduced the number of calls Scott gets in the interim, but it’s also improved his company’s reputation for customer service. “No one else around here proactively does follow-up quality-­control inspections, so it really sets us apart.”