The rainscreen retrofit process
A rainscreen retrofit rebuilds a wall from the sheathing out while people keep living behind it. The cladding comes off, the rot comes out, and a drained assembly goes on: barrier, flashings, strapping, cladding. Done in the right order, elevation by elevation, it is a manageable construction project. This guide walks the seven stages and the decisions each one carries.
What a retrofit is, and when it is the answer
A rainscreen retrofit converts a face-sealed wall into a drained one. Everything our guide to how a rainscreen works describes, the cavity, the water resistive barrier, the flashings, the weeps, gets built onto a structure that never had them. It is the deepest intervention in the envelope repair spectrum, and it competes with lighter options: targeted repairs, coatings, and sealant renewal all have their place when the structure behind the wall is still sound. Our envelope repair vs recladding comparison covers how consultants draw that line.
The retrofit wins when the diagnosis says the wall assembly itself is the problem. Widespread moisture in a face-sealed wall, rot at multiple test openings, or a pattern of leaks that tracks the wall design all point past patching. First confirm what you own using the checks in is my building rainscreened, because more than one strata has budgeted for recladding a wall that turned out to be a rainscreen with blocked drainage.
The seven stages
Every project has its own drawings, but the spine of the work barely changes from a Coquitlam low-rise to a West End tower.
Assessment and design
An envelope consultant probes the walls, maps the damage, and produces drawings and specifications for the new assembly. This stage sets the cladding system, the water resistive barrier, every flashing profile, and the sequencing plan. Skipping or rushing it is how retrofits blow past their scope later, because the wall you design for is a guess until someone has looked inside it.
Mobilization and resident protection
Access goes up: scaffolding or mast climbers on full elevations, rope access for localized zones on towers. Windows get protection film, balconies are cleared, and the strata communicates the schedule suite by suite. On an occupied building this stage decides whether the project runs smoothly or becomes a two-year argument at every council meeting.
Strip the cladding
The existing cladding, and on face-sealed walls usually the sheathing paper behind it, comes off one elevation at a time. This is the moment of truth: the concealed condition of the sheathing and framing is finally visible, and the consultant walks the exposed wall to confirm or revise the repair scope before anything gets covered up again.
Remediate the structure
Rotted sheathing is cut out and replaced, decayed framing members are sistered or renewed, and concrete or masonry substrates get their own repairs. The quantity found here drives more of the final cost than any other line item. Honest contracts price this work per unit measured in place, documented with photos, because nobody knows the true quantity until the wall is open.
New barrier and flashings
The water resistive barrier goes over the repaired sheathing, lapped shingle style and sealed at every penetration. Window and door head flashings, cross-cavity flashings at floor lines, saddle flashings, and parapet metal are installed and tied into the barrier. This hidden layer is the actual rainscreen; everything after it is weather protection and appearance.
Strapping, cladding, and sealant
Strapping establishes the drained cavity, insect screen and vent strips go in at the base and head, and the new cladding closes the wall. Sealant joints are tooled where the design calls for them. Weep paths are verified open before the crew leaves each elevation, because a retrofit that ships with blocked weeps has rebuilt the old problem at new prices.
Review, documentation, and warranty
The consultant reviews the completed assembly against the specifications, deficiencies are corrected, and the strata receives as-built records, maintenance requirements, and warranty documents. File all of it with the depreciation report records. The next council, ten years on, will make better decisions because this paper trail exists.
Sequencing on an occupied building
The elevation-by-elevation rhythm exists for weather and for people. An open wall in a Metro Vancouver winter is a liability, so crews strip only what they can protect, and the drier months carry the heaviest stripping and membrane work. Meanwhile the residents absorb the project one face at a time: the south suites lose their outlook for a stretch, then the work rotates and they get it back. Councils that communicate that rotation early, with dates, spend far less of the project managing complaints.
Sequencing is also where the retrofit decision meets its bigger cousin: whether to do all elevations in one continuous project or split them across budget years. That trade, and the misdiagnosis risk hiding inside it, gets its own treatment in our staged vs whole-building remediation guide.
Where the money and the risk concentrate
Two stages dominate both. Stage 4, structural remediation, carries the cost risk, because the rot quantity is unknowable until the wall is open. The defence is contractual honesty: unit rates, measured quantities, photographic records, and a consultant confirming every count. Be wary of any bid that claims certainty about a closed wall.
Stage 5, the barrier and flashings, carries the performance risk. The new wall will only drain as well as its hidden layer is detailed, and this is exactly the layer nobody can inspect after the cladding closes. The membrane choices behind that layer are compared in our WRB membrane options guide, and the cladding decision that follows in cladding choices in coastal rain. Insist on consultant sign-off photos of the barrier and every flashing before cover-up; that photo file is worth more than the brochure of any product on the wall.
After the crews leave, the retrofit becomes a maintenance obligation like any other rainscreen, with weeps to keep clear and sealant to renew on a cycle. Our rainscreen services team handles both the localized repair end of this work and the long maintenance tail that follows a successful project, and the rainscreen hub collects the guides a council needs for the years in between.
Quick answers
What does a rainscreen retrofit involve?
A rainscreen retrofit strips the existing cladding off a face-sealed wall, repairs whatever rot the stripping reveals in the sheathing and framing, then rebuilds the wall as a drained assembly: new water resistive barrier, new flashings, strapping to create the cavity, and new cladding with open weep paths at the base. On an occupied strata the work runs elevation by elevation under an envelope consultant’s review.
Can residents stay in the building during a rainscreen retrofit?
Residents almost always stay during a rainscreen retrofit. The work happens from outside, on scaffolding, mast climbers, or ropes, and suites keep their windows and services throughout. The honest costs of staying are noise, covered windows on the active elevation, lost balcony use, and a construction site in the parking area. Good contractors publish a rolling schedule so each suite knows when its wall goes loud.
Why is a retrofit sequenced elevation by elevation?
Retrofits run elevation by elevation because an open wall is a vulnerable wall. Stripping one face at a time limits how much of the building stands exposed when a Pacific system rolls in, keeps temporary weather protection manageable, and lets crews, hoarding, and access equipment concentrate where the work is. It also spreads the disruption, so no resident lives behind a covered window for the whole project.
Retrofit process questions
What does a rainscreen retrofit involve?
A rainscreen retrofit strips the existing cladding off a face-sealed wall, repairs whatever rot the stripping reveals in the sheathing and framing, then rebuilds the wall as a drained assembly: new water resistive barrier, new flashings, strapping to create the cavity, and new cladding with open weep paths at the base. On an occupied strata the work runs elevation by elevation under an envelope consultant’s review.
Can residents stay in the building during a rainscreen retrofit?
Residents almost always stay during a rainscreen retrofit. The work happens from outside, on scaffolding, mast climbers, or ropes, and suites keep their windows and services throughout. The honest costs of staying are noise, covered windows on the active elevation, lost balcony use, and a construction site in the parking area. Good contractors publish a rolling schedule so each suite knows when its wall goes loud.
Why is a retrofit sequenced elevation by elevation?
Retrofits run elevation by elevation because an open wall is a vulnerable wall. Stripping one face at a time limits how much of the building stands exposed when a Pacific system rolls in, keeps temporary weather protection manageable, and lets crews, hoarding, and access equipment concentrate where the work is. It also spreads the disruption, so no resident lives behind a covered window for the whole project.
How much hidden rot will be found when the cladding comes off?
Nobody can state a rot quantity before the cladding comes off, and a fixed number in a bid should raise questions. The honest structure is a measured allowance: exploratory openings during design give a projection, the contract carries unit rates for sheathing and framing replacement, and quantities are documented as the walls open. South and southeast exposures, deck interfaces, and window heads reliably hold the worst of it.
Who designs a rainscreen retrofit on a strata building?
A building envelope consultant, usually a professional engineer or architect with envelope specialization, designs a rainscreen retrofit. The consultant produces the drawings and specifications, reviews the exposed structure once cladding is stripped, checks the barrier and flashing installation before cover-up, and certifies the finished assembly. The contractor builds to that design. On a project this consequential, the design and construction roles belong in separate hands.
What happens to windows during a rainscreen retrofit?
Windows are a live decision inside every rainscreen retrofit. The wall around each window is being rebuilt anyway, so replacing aging units at the same time costs far less than returning for them later and cutting into a finished assembly. Where existing windows stay, the retrofit still rebuilds their perimeter details: head flashing, sill pan, and the membrane tie-ins that make the frame part of the drainage path.
How long does a rainscreen retrofit take on a strata building?
Retrofit duration is set by scope, and honest answers come as a schedule against your building, never as a rule of thumb. The drivers are the number and size of elevations, how much structural repair the stripping reveals, the cladding system chosen, and how many months of workable weather the calendar offers. The consultant’s design package normally includes a sequenced schedule, and progress is measured against it elevation by elevation.
Does a rainscreen retrofit change how the building looks?
Usually, yes. A retrofit replaces the entire visible skin, so most stratas take the chance to update cladding materials, colours, and trim profiles, and the wall also gains a little thickness from the cavity and strapping. Councils weigh the appearance options during design; our guide to cladding choices in coastal rain compares the candidates. A like-for-like appearance is possible too, where bylaws or owner preference call for it.
What weather windows matter for retrofit work in Vancouver?
The stages that matter most are stripping and barrier installation, when the wall is open or the membrane is going down. Metro Vancouver’s drier late spring through early fall is the preferred window for opening large wall areas, and winter work is possible with temporary weather protection and tighter sequencing. Crews plan around forecasts week by week either way, because an exposed elevation and an atmospheric river make an expensive combination.
Is scaffolding always needed for a rainscreen retrofit?
Full recladding of an elevation needs continuous access, which means scaffolding or mast climbers for most low and mid-rise work. Rope access earns its place around the edges of a retrofit: exploratory openings during design, localized repairs on towers, flashing and sealant work at parapets, and post-project maintenance, all without staging costs. Many Metro Vancouver retrofit projects run both, matching the access method to each task.
Facing a recladding decision?
We work on envelope remediation and the maintenance that follows it across Vancouver, Burnaby, Coquitlam, and the North Shore, and we will tell you honestly whether your wall needs a retrofit or a repair.