When to Recaulk a Commercial Building, Joint by Joint

There is no single recaulking interval for a commercial building. Washroom and kitchen beads in busy facilities usually need redoing every one to three years, interior window and door trim every five years or so, and good exterior perimeter sealant can last ten to twenty years. The better rule is to inspect every joint once a year, ideally in early fall before the cold sets in, and replace any bead that has split, pulled away, discoloured or grown mould.

Why the interval varies so much

A caulk joint fails for three reasons: the sealant itself ages, the joint moves more than the sealant can stretch, or the surface it was stuck to was never clean and dry. The product matters too. Acrylic latex caulk is cheap, paintable and easy to tool, but it is stiff and has a short life in wet or moving joints. Silicone handles water and movement very well and resists UV, but most silicones cannot be painted. Polyurethane and hybrid (silyl-modified polymer) sealants sit in between and are common on exterior concrete and masonry.

For exterior work, look for sealants that meet ASTM C920, the standard for elastomeric joint sealants, and check the movement class on the data sheet. A sealant rated for plus or minus 25 percent movement in a joint that moves more than that will crack no matter how well it was applied.

Typical intervals by location

These are typical ranges for commercial buildings with normal use. Heavy traffic, harsh cleaning chemicals and big seasonal temperature swings all shorten them.

Washrooms (sinks, vanities, toilet bases, tub and shower surrounds) One to three years. Daily wet cleaning, disinfectants and constant splashing break down even mould-resistant silicone. In high-traffic public washrooms, plan on an annual look and expect to redo the vanity and toilet-base beads every couple of years.

Commercial kitchens and break rooms One to two years around sinks, backsplashes and food prep counters, especially where hot water, degreasers and steam cleaners are in daily use. Food-safe areas may call for sealant listed for that use, so the product choice belongs in the scope.

Interior window stools, door frames and trim Five years or more for painted acrylic, often longer. These joints mostly fail cosmetically: hairline cracks along the trim as the building dries out in winter. A patch-and-paint visit is a good time to catch them.

Exterior window and door perimeters Ten to twenty years for a quality silicone or polyurethane installed with proper backer rod and a clean, primed surface. Cheaper products or poor prep can fail in three to five. South- and west-facing elevations age faster because of sun exposure.

Exterior penetrations (vents, conduit, hose bibs, sign mounts) Check every year. These small joints get disturbed when other trades work on the building, and a gap around a dryer vent or conduit is a common path for water and pests.

Expansion and control joints in concrete or masonry Seven to fifteen years depending on movement, traffic and product. Joints in sidewalks and loading areas take a beating from plows, de-icing salt and forklifts, so they usually go first.

Signs a bead has already failed

You do not need a schedule to spot a failed joint. Walk the building and look for:

• Splits down the middle of the bead (cohesive failure, usually too much movement or the wrong sealant)
• The bead peeling away from one side (adhesive failure, usually poor surface prep or no primer)
• Black or pink staining that does not wipe off, a sign of mould growing in or behind the sealant
• Hardened, chalky or shrunken caulk that has lost its flexibility
• Water stains on drywall or ceiling tiles below windows, a draft at a door frame, or daylight visible through a gap
• Gaps between a vanity top and the wall where someone has re-caulked over old caulk more than once

That last point matters. Running a new bead over a failed one hides the problem for a few months. The old sealant has to come out, the joint has to be cleaned and dried, and the new bead goes onto bare, sound material.

Fall is the window for exterior joints

Most sealant manufacturers set a minimum application temperature, often around 4°C (40°F), and require the surface to be dry and above the dew point. In much of Canada and the northern US that window closes in November. Interior washrooms and kitchens can be done all winter, but exterior perimeters and penetrations should be inspected and repaired while daytime temperatures still allow it. If an exterior joint fails mid-winter, a temporary cold-weather sealant can stop the water until spring, when the joint should be properly redone.

The commercial building winterization checklist covers caulking alongside the rest of the cold-season prep, including weatherstripping and door sweeps.

What a handyman visit covers, and what it does not

Recaulking washrooms, kitchens, counters, interior trim, window and door perimeters reachable from the ground or a stepladder, and small exterior penetrations is routine handyman work. It batches well with other small items on a monthly or quarterly visit, and the cost per joint drops when several are done in the same trip.

Some joints belong with a specialist:

• Firestop sealant at fire-rated walls and floors, where cables and pipes pass through. These are tested and listed systems, and fire codes expect them to be installed and repaired to the listing. A handyman should flag damaged firestop, not patch it with ordinary caulk.
• Curtain wall and storefront glazing seals, which are part of the glazing system and usually need a glazing contractor and a lift or swing stage.
• High exterior joints that need scaffolding, a boom lift or rope access.
• Large expansion joints in parking structures, roofs or plazas, where the joint design and backer system matter as much as the sealant.

A good scope names each joint by location, says what product goes in, and lists the specialist items separately so nothing gets quietly skipped.

Frequently asked questions

How often should caulking be replaced in a commercial washroom?

In most commercial washrooms, the beads around vanities, sinks and toilet bases need replacing every one to three years. High-traffic public washrooms and those cleaned with strong disinfectants sit at the short end. An annual inspection catches mould and peeling before water gets behind the fixture.

Can you caulk over old caulk?

It is not a good idea. New sealant does not bond well to old, failing caulk, so the fresh bead tends to peel within months and can trap moisture underneath. The old material should be cut and scraped out, the joint cleaned and dried, and a new bead applied to the bare surface.

Can exterior caulking be done in winter?

Most sealants need surface and air temperatures above roughly 4°C (40°F) and a dry, frost-free surface, so exterior caulking is best done before late fall. Some products are rated for colder application, and a temporary repair can stop a leak, but a proper replacement usually waits for spring.

Is silicone or acrylic caulk better for commercial buildings?

It depends on the joint. Silicone is the better choice for wet areas and joints that move, while acrylic latex suits painted interior trim where flexibility demands are low. Exterior joints usually call for a silicone, polyurethane or hybrid sealant that meets ASTM C920.

Get a recaulking scope for your building

Send the list of washrooms, kitchens, windows and exterior joints that need attention through the quote form, and we will return a written, itemized scope with specialist items flagged separately. Recaulking can also be folded into a scheduled preventive visit for buildings in Montréal, Toronto and other cities we serve.