Water is coming in after every storm. Is it the caulking?
It is the caulking if the water shows up below a joint you can see daylight or a knife blade behind, and it stops when that joint is temporarily sealed. It is something else if the wet spot sits in the field of a panel, inside a window unit, or below a parapet. Sealant on a Front Range building is realistic for 10 to 15 years, and a tilt-up warehouse from the early 2000s or a precast office tower from the 1980s is past that either way, so the smart first step is a walk of the sunny elevations with a putty knife, not a purchase order.
Failed sealant almost always announces itself on the south and west faces first. Altitude UV and 40 degree daily temperature swings work the bead thousands of cycles a year, which is why joint design matters more than cartridge brand. The industry reference on that is ASTM C1193, the standard guide for use of joint sealants, and the Whole Building Design Guide’s building envelope section covers why joints, not wall panels, are where most water gets in.
What failed sealant looks like, by failure type
Five patterns cover nearly every failed joint we survey on commercial buildings in Aurora. Each one points to a different cause and a different fix.
| Failure | What you see | What it means |
|---|---|---|
| Adhesive failure | The bead pulled cleanly away from one side of the joint. A putty knife slides behind it. | Poor prep or no primer on the last job, or the joint moves more than the sealant class allows. Most common failure we see on tilt-up and precast. |
| Cohesive failure | The bead split down its own middle and both halves are still stuck to the walls. | Sealant installed too thin or with no backer rod, so it stretched from the back instead of the middle. Full removal and a rebuilt joint. |
| Weathering | Surface is chalky, crazed like dried mud, or hard like an old eraser. | Age plus altitude UV. The joint may still be tight today, but it is at end of life and the sunny elevations go first. |
| Reversion | The bead went soft, gummy or sticky and picks up dirt. | Chemistry problem, usually a urethane that was never right for the exposure. Comes out entirely, never topped over. |
| Substrate failure | Sealant is intact but the panel edge behind it spalled or the EIFS is soft. | Not a caulking job yet. The edge gets repaired first, then the joint is rebuilt. Priced per location at the survey. |
Which leaks are not a caulking problem
Roughly one leak in three that we are called for is not a sealant leak at all. These are the five we see most, and what they usually turn out to be.
Water shows at the head of a window on a lower floor, joints above look fine
Failed or missing head flashing, or a leak higher up traveling inside the wall. We hose test from the top down before anyone recaulks the wrong joint.
Wet spot in the middle of a tilt-up panel, nowhere near a joint
A shrinkage crack through the panel or a lift insert pocket that was never sealed. Crack injection or pocket patch, not a sealant reseal.
Water in the glazing pocket or between the panes
Glazing gasket or setting block problem inside the window system. A wet seal helps only if the gasket is the leak.
Staining that starts at the parapet and runs down
Coping cap joints or roof edge, a roofing trade item. Wall sealant below it is a symptom.
Damp at the slab line after snowmelt
Grade and drainage, sometimes a slab joint. The vertical wall joints above are usually innocent.
Can I just spot repair the bad sections, or does the whole building need resealing?
Spot repair makes sense when less than about a fifth of the footage on an elevation has failed and the rest still passes a knife test. Past that point, a full elevation reseal costs less per foot and stops the call backs, because the joints that look fine today were installed the same week as the ones that failed. The rule we use at the survey:
1.Under 20 percent failed on the elevation, joints otherwise sound
Spot repair the failed runs. Expect the $2,200 minimum mobilization to dominate a small scope.
2.20 to 50 percent failed, or failures on every elevation
Reseal the sun exposed elevations in full this season, hold pricing on the shaded ones for next year.
3.Over 50 percent failed, or any reversion or cohesive failure
Full building reseal. Topping or patching this joint just buys a second failure. Budget from the cost guide: $4 to $9 per foot at ground reach, $9 to $18 from a lift.
4.Sealant intact but panel edges spalled
Concrete edge repair first, per location, then a rebuilt joint. Get that scope itemized before comparing bids.
Full worked examples for a tilt-up warehouse, an EIFS strip center and a three story office are on the cost guide. If the building is tilt-up or precast, the panel joint page covers the removal and backer rod detail that decides how long the new seal lasts.
Red flags when you are getting caulking bids
The spread between caulking quotes on the same building is usually explained by what the low bidder left out. Six things to check before you sign.
1.The quote has no linear footage
A lump sum with no footage cannot be compared to anything, and it hides what is being skipped. Every quote should list feet by joint type and elevation, the way our cost guide is laid out.
2.Nobody mentions removing the old sealant
Topping new sealant over old is the single most common shortcut. It fails in two or three winters because nothing bonds to weathered sealant. Ask directly whether the old bead is cut out to clean substrate.
3.No backer rod on the scope
Without backer rod the bead cures at the wrong depth and tears from the back. If the bidder cannot explain joint depth to width ratio, keep looking.
4.The product is not named
You should know whether you are getting a silicone or a urethane and which one, because that decides the warranty length and how it ages. The quote should name the product.
5.No adhesion test before the price
A pull test on your actual substrate takes ten minutes and prevents a whole elevation failing. Skipping it means the price is a guess.
6.No certificate of insurance
Colorado has no state license for this trade, so insurance is the paperwork that matters. If a certificate is not offered with the quote, that tells you something.
Who we are not the right fit for
We are a commercial exterior sealant contractor, and there are jobs we will tell you to call someone else for. Single family homes and townhome interiors: a handyman or painter will do window and tub caulking for a fraction of our mobilization. One leaking window on an otherwise sound building: a glazier is the right call. Roof and parapet cap leaks: a roofer, and we will say so at the survey rather than recaulk the wall below it. Interior fire caulking and firestopping: a firestop contractor with the listings. What we do is panel joints, EIFS and stucco, window and curtain wall perimeters and parking garage expansion joints, on buildings from a strip center up to a tower, anywhere from Aurora and Denver out to Parker and Lakewood.