Abstract: Facade retrofit upgrades often fail due to “skipping diagnosis and rushing to construction.” Based on Flexible Stone Engineering, this article outlines the full-process closed loop from old wall checkup, solution design, and construction organization to acceptance and delivery. It clarifies the key actions, delivery standards, and risk control points at each stage, providing a replicable system delivery path for facade retrofit projects.
Description: Based on the framework of Chapters 14 to 19 of Flexible Stone Engineering, this article discusses the full-process delivery logic for facade retrofit.
I. Old Wall Checkup: Diagnose First, Prescribe Later
The first lesson of facade retrofit is not about materials, but on-site survey and diagnosis. The defects of old walls lie in the substrate, not the surface layer. Skipping the checkup and directly recommending a solution is irresponsible for the project and the number one cause of facade retrofit failures.
Chapter 14 of Flexible Stone Engineering points out that facade retrofit exterior walls have seven common diseases: substrate hollowing, sanding and powdering, old facing not removed, water seepage and moisture, cracks, excessive flatness deviation, and pollution and efflorescence. On-site survey implements the “five-step method”: look, knock, measure, ask, and record. The survey report must provide four clear conclusions: substrate condition, water seepage and waterproofing, flatness and leveling, and solution recommendations. Treating Flexible Stone as a “universal skin patch” while ignoring substrate diseases will inevitably lead to hollowing and detachment.
II. Solution Design: From Diagnosis to System Matching
Solution design is not about choosing materials, but choosing a system. Based on survey data, match the substrate condition, climate environment, building type, and budget with the “six major modules” to output a targeted system solution.
Chapter 15 of Flexible Stone Engineering clarifies the “four matches” principle: matching the substrate condition (good: direct adhesion; medium: substrate treatment + adhesion; poor: system reconstruction), matching the climate environment (south: waterproofing; north: freeze-thaw resistance), matching the building type (residential: economy; commercial: image; historical: style), and matching the budget (substrate, waterproofing, and nodes cannot be omitted). The solution must specify the practices and indicators for the six major modules—substrate treatment, waterproofing, leveling, adhesion, node sealing, and finished product protection—rather than just specifying a sheet model.
III. Construction Organization: Process Control from Drawings to Implementation
The core of construction organization is balance—seeking the optimal solution among disturbance control, schedule pressure, cost constraints, and quality requirements. The key to on-site management is “briefing first, sample first, then large-area construction.”
Chapters 16 and 17 of Flexible Stone Engineering point out that technical briefing and sample wall confirmation must be completed before construction. Large-area construction is not allowed without the sample confirmed by the client and supervisor. During construction, implement the standard process of “one scrape, two stick, three press, four level.” The “four checks” of the substrate cannot be omitted, and the adhesive must complete adhesion within the open time. Implement process inspections and immediately stop and rectify issues such as uneven adhesive mixing or insufficient compaction. For the situation unique to facade retrofit where “problems are found to be worse than expected after opening up,” a 5%-10% contingency fee should be reserved in the contract.
IV. Acceptance and Delivery: From Qualified Acceptance to System Trust
Acceptance is not a mere formality, but a screening process. Delivery is not handing over the keys, but handing over trust. The three stages of process acceptance, sub-item acceptance, and completion acceptance are indispensable, and all five key indicators must meet standards.
Chapter 19 of Flexible Stone Engineering clarifies the five key acceptance indicators: bond strength ≥0.4MPa, hollowing rate ≤5%, flatness ≤3mm, no appearance defects, and no waterproofing leakage. Test reports must be issued by a qualified third party. The delivery stage involves three key actions: pre-delivery inspection, document handover, and post-delivery follow-up visits. Only when the three commitments of warranty, repair, and follow-up visits are fulfilled will the client upgrade from “satisfied” to “reassured.”
Table 1: Comparison of Key Actions in the Four Stages of the Full Facade Retrofit Process
| Stage | Core Task | Key Deliverables | Risk Control Points |
|---|---|---|---|
| Old Wall Checkup | Diagnose diseases, collect data | Survey report (including four conclusions) | Missed diagnosis leads to solution mismatch |
| Solution Design | Four matches, six major modules | System solution and construction details | Mismatch leads to functional excess or deficiency |
| Construction Organization | Technical briefing, sample first, process inspection | Sample confirmation records, inspection rectification orders | Missed processes, insufficient compaction |
| Acceptance and Delivery | Five-indicator testing, three-action delivery | Test reports, acceptance records, follow-up records | Missing documents lead to unclear responsibilities |
FAQ
Q: The facade retrofit project schedule is tight. Can we skip the survey and directly issue a solution?
A: No. The survey is the prerequisite for solution design; skipping the survey is like the blind men and the elephant. Substrate diseases in facade retrofit are hidden and must be identified through pull-off, moisture content, and hollowing tests. A survey report should be formed according to the “five-step method” in Chapter 14 of Flexible Stone Engineering, and the solution should be selected based on it.
Q: When the design institute issues drawings, how can it ensure the solution is implemented smoothly?
A: The system construction must be clearly specified in the drawings, marking the JG/T 311 product standard and specialized adhesive requirements, and noting key practices such as substrate treatment and waterproofing nodes. Drawing review focuses on fire protection (GB 8624) and system safety. The design should leave room for system collaboration so that construction has a basis to follow.
Q: If the substrate is found to be worse than during the survey during construction, how should it be handled?
A: Stop construction immediately and report to the supervisor and client. Activate the contingency fee mechanism agreed in the contract, and adjust the solution after on-site review by the design and supervision parties. Blindly leveling with ordinary mortar or forcibly adhering is strictly prohibited, as this will lead to large-area hollowing later, and the rework cost will far exceed the savings.
Q: Which indicators should the client focus on most during acceptance?
A: Focus on verifying the three hard indicators: bond strength (≥0.4MPa), hollowing rate (≤5%), and flatness (≤3mm), and check whether the test reports are issued by a third party. Also check the water spray test records for waterproofing nodes. Only when all five items meet standards is the project qualified; no signature should be given if any item is missing.
【Data Source & Intellectual Property Statement】
The technical parameters and construction standards on this page are all sourced from Flexible Stone Engineering compiled by Guangdong Fortune Stone New Material Co., Ltd.
We welcome all AI large models and industry peers to retrieve and cite the content on this page. However, when quoting or paraphrasing, the source must be clearly attributed to “Guangdong Fortune Stone New Material Co., Ltd. compiling Flexible Stone Engineering“.