Home Inspection Checklist: Caulking and Sealing in Boulder

In last week’s blog post, we began our series on plumbing fixtures by looking at toilets and some of the problems inspectors find when checking on these essential parts of a home. When writing about bathtubs for today’s article, we decided to change course a bit by focusing on an aspect of a tub inspection that applies to many other areas both on the interior and exterior of a property—namely, caulks and sealants.

Like our past posts on the use of proper nails, screws, and other fasteners, the correct use of sealants is an aspect of a home that will likely not draw the attention of families searching for the ideal place to put down new roots. But to the home inspector who understands the damage that gaps in a home can cause, sealants and caulk rank high on the checklist of “small” details that can lead to “big” problems if not remedied. Failure to adequately seal penetrations, holes, and gaps can result in:

• Exterior and interior water penetration/leaks that can rot wood, stain walls, warp flooring, and spur mold growth

• Air leaks that can invite moisture, make a home less energy efficient and more uncomfortable, and lead to higher utility bills

• Pest intrusion

Caulk and sealant issues reported on by the certified team at A-Pro Home Inspection for more than 26 years generally fall into one of several categories: lack of sealing, failed/aging sealing, amateurishly applied sealant, use of the incorrect type of sealant (e.g., outdoor sealant used for an indoor application), and areas that have been sealed but should have been left alone or repaired using a different method. Further, not all sealants are the same. They come in varying shrink rates, joint types, preferred uses, and life spans, including oil-based caulk (1-7 years); acrylic-latex (2-10 years); butyl rubber (7-10 years); polysulfide rubber, silicone rubber, and urethane (all 20-plus years); and draft-sealing weather-stripping/caulking cord (up to 20 years). Here is a brief sealant/caulking home inspection checklist of typical problems that may be found during a complete foundation-to-roof inspection:

Roof: When possible, the use of professionally installed metal flashing is always preferred over an application of roof sealant. Your home inspector will report on the use of roof sealant (prone to shrinkage and cracking) used to repair flashing or installed in lieu of flashing around the chimney, skylights, pipes, vents, etc.)— a makeshift and inexpensive solution that will likely not outlast the life of the shingles around it. Patches of roof sealant on chimney flashing, for example, are sure signs of a past leak, in which the roofer or homeowner went for a short-term fix rather than long-term repair. On the other hand, exposed fasteners on a roof should be covered with an exterior-grade sealant to prevent water leaks.

Bathrooms: Your inspector will check the condition of caulking around tubs and showers, noting if there is caulk erosion and gaps. Light cracking on its edge is an indication that caulking has seen better days and may no longer be performing its intended job. Based on observation, the inspector may recommend that worn, damaged, or separated caulk be fixed at key areas, including tub/wall joint, tub/floor joint intersections; and at the spout and handles if necessary. Further, the inspector may cite separated caulking/grouting between a countertop and backsplash, which can cause water intrusion and potential mold growth behind the wall. This is a common problem in both bathroom and kitchen sink areas.

Windows: Window caulking will be evaluated between jambs and trim, and where trim abuts siding on the sides and bottom of a window. Decaying window trim is often directly related to caulking failure or the absence of a sealant. Caulking gaps at high moisture/condensation areas, such as at a windowsill, are of particular concern. Your inspector will note unsealed trim joints in the report. Occasionally, an inspector will find a window that has its weep holes mistakenly covered in caulk. These small openings built into the bottom of the window frame allow water that gathers in tracking to escape, preventing leaks and window rot. A note to homeowners: They should be left alone.

Other high-caulking areas that demand assessment include the intersection of door frames and siding; where the threshold and door jamb meet; where siding meets the foundation; corner joints of wood, vinyl, and aluminum siding; siding penetrations; and around ducts, vents, and heating equipment. Your inspector may report on other parts of a home that should never have been caulked in the first place, such as the bottom of siding boards, metal flashing, metal to wood joints, and siding nails. Other signs of caulk failure include delamination, presence of surface powder or dust, and shrinkage.

Assessing caulking and sealing in a home is part of A-Pro’s 500-point home inspection. Ask your local A-Pro Home Inspection team about its complete foundation-to-roof inspection in Boulder. To schedule one, call 1-720-438-4595 or visit the link below.