Commercial · St. Louis, MO
Cracked caulk lines, staining, or a split control joint usually means your stucco expansion joint has failed and water is getting behind the wall. Superior Stucco St. Louis repairs and replaces stucco expansion joints so your system can move safely, stay watertight, and match the surrounding finish.
We start by confirming the joint type and what is actually moving: true expansion joint, control joint, or a failed sealant joint at a dissimilar material like brick, windows, doors, or a deck ledger. Next we protect landscaping, set dust control, and remove loose stucco, failed sealant, and rusted metal lath around the joint line until we reach sound material. The base gets cleaned, dried, and evaluated for sheathing damage, then we install or repair the weather-resistive barrier (WRB) and flashing details as needed. For cement stucco we reattach lath with corrosion-resistant fasteners, then rebuild the base coat with polymer-modified cement plaster and embed alkali-resistant fiberglass mesh where cracking risk is high.
St. Louis freeze-thaw swings and humid summers are hard on sealants and joint accessories, so we choose materials that stay flexible and bond to cementitious stucco. We install the correct backer rod depth, then apply a high-performance polyurethane or silyl-terminated polyether (STPE) sealant with proper tooling for a consistent hourglass profile. If the joint needs a physical break, we install new PVC expansion joint or casing bead accessories and tie them into the surrounding coats so movement happens at the right plane. After cure, we blend the finish to match existing texture, including sand-float, lace, dash, or smooth finishes, and we can color-match with acrylic finish coats or breathable masonry coatings when appropriate.
Customers choose us because we fix the cause, not just the crack line. We understand three-coat stucco, one-coat assemblies, and repairs around EIFS transitions, and we pay attention to WRB laps, kick-out and head flashing, weep screeds, and termination details that prevent repeat leaks. Our crews use the right equipment for clean work, including grinders with HEPA vacs, mixing paddles for consistent batches, and moisture meters to verify the substrate is ready before we close it up. You get clear options, straightforward pricing, and a repair that is built around movement and drainage, not cosmetic patching.
At the end, we walk the joint line with you and explain what was replaced, what was sealed, and where movement was designed to occur. You receive a written scope, material selections (joint accessory type, backer rod size, sealant class), and care guidance so the joint lasts longer, including when to re-inspect and how to keep sprinklers and downspouts from soaking the wall. We clean up thoroughly, remove masking, and leave the finish blended so the repair does not draw the eye. If we find related issues like missing weep screed, failed flashing, or soft sheathing, we document it and provide a plan before small problems become major stucco failure.
Yes. We provide a free written estimate that outlines the scope, materials, and the recommended repair or replacement approach.
Yes. We repair and install traditional cement stucco and EIFS systems, using compatible base coats, mesh, accessories, and finish coats for the existing assembly.
Temperature and moisture matter for curing and adhesion. We schedule work around conditions and use appropriate protection so base coats and finishes cure correctly and avoid washout or freezing.
Frequent causes include missing or incorrect flashings, poor WRB laps, buried weep screeds, inadequate lath fastening, lack of control joints, and sealant failure around penetrations and openings.
Small patches may take 1-2 days plus cure time, while larger remediation or full replacements take longer due to demo, substrate repairs, multiple coats, and drying time between steps.
A stucco expansion joint is a planned break that lets cement plaster move with temperature changes, framing shrinkage, and structural movement. When that joint is bridged with stucco, installed incorrectly, or sealed with the wrong product, you will often see straight-line cracking, separation at corners, staining, and water intrusion around windows or transitions. Superior Stucco St. Louis repairs stucco expansion joints by restoring the movement gap, rebuilding the base correctly, and sealing it with durable, compatible materials.
Expansion joints are not just caulk lines. In traditional three-coat stucco, joints are created with accessories like PVC expansion joint, casing bead, and control joint products that separate plaster panels. When those accessories are missing, buried, or damaged, stress concentrates and cracks return quickly. Our process focuses on sound edges, proper lath termination, reinforced base coats with alkali-resistant mesh where needed, and a continuous drainage plane behind the repair.
Sealant choice and installation matter as much as plaster work. We size the joint, set the right backer rod, and use high-performance polyurethane or STPE sealants that adhere to cementitious substrates and stay flexible through seasonal cycles. Too much sealant depth, poor surface prep, or painting too soon can cause adhesion loss and tearing, so we follow manufacturer cure times and prep requirements.
If your stucco expansion joint is opening up, leaking, or repeatedly cracking, it is usually telling you the wall is moving or shedding water incorrectly. We inspect adjacent flashings, penetrations, and transitions and recommend targeted corrections so the repair holds. Schedule a free written estimate and get a joint repair that is built for movement, drainage, and a clean finish match.
Call now or send a request and we will reach out within one business day to schedule your free, no-obligation estimate in St. Louis. We assess the project, review the details, and give you a written quote before any work starts, so you know exactly what to expect.
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