Temporary Weatherproofing During Recladding

Stripping the external envelope of a high-rise building is a significant undertaking that leaves the internal structure vulnerable to the unpredictable British climate. Temporary weatherproofing during recladding refers to the strategic implementation of barriers, membranes, and structural seals designed to prevent water ingress and wind damage while the primary façade is missing. Without a robust strategy for temporary facade protection recladding, even a brief period of exposure can lead to extensive internal damage, mould growth, and project delays.

For building owners and managing agents, the transition between removing non-compliant materials and installing new systems is a period of high risk. This is particularly true for occupied buildings, where residents remain in situ during remediation. Ensuring the building remains watertight is not just a matter of convenience; it is a critical requirement for maintaining the structural integrity of the substrate and the safety of the living environment.

Effective weatherproofing requires a multi-layered approach. It involves coordinating the cladding strip out weatherproofing phase with the immediate application of temporary breathable membranes or liquid-applied barriers. This ensures that the building "breathes" to prevent condensation while remaining impervious to driving rain and gale-force winds common across the UK.

Key Takeaways#

• Preventative Strategy: Weatherproofing must be planned prior to the first panel being removed to avoid emergency reactive measures.
• System Compatibility: The temporary protection must not interfere with the fire performance or fixings of the new, permanent cladding system.
• Resident Comfort: Effective moisture control prevents internal damp and maintains thermal performance for occupants during the works.
• Substrate Protection: Keeping the inner leaf (SFS, masonry, or timber frame) dry is essential to prevent long-term structural decay.
• Regulatory Compliance: All temporary materials must meet stringent UK fire safety standards, especially on buildings over 11 or 18 metres.

The Fundamentals of Weatherproofing During Façade Remediation#

When a building undergoes cladding testing and is found to require remediation, the focus often shifts immediately to the new materials. However, the period between the "strip-out" and the "re-install" is where the most acute physical risks to the building fabric occur. Temporary weather protection cladding removal is the discipline of managing this gap.

The primary goal is to maintain the "line of the envelope." Once the rainscreen is removed, the secondary line of defence—usually a breather membrane and insulation—is often either non-existent or damaged. The strategy must involve sealing windows, door openings, and floor slab interfaces to ensure no water travels behind the internal finishes.

Why Exposure is a Critical Risk#

Unprotected substrates, such as Steel Flick Frame (SFS) with cement particles or gypsum-based sheathing boards, can degrade rapidly when saturated. If these boards absorb water, they lose structural integrity, potentially requiring a full replacement of the inner leaf—massively increasing project costs and timelines. Weatherproofing during cladding replacement is therefore a form of insurance against secondary damage.

Furthermore, in the UK, wind loads on high-rise buildings can be substantial. Temporary membranes must be mechanically fixed or bonded securely to ensure they do not detach during a storm, which could create a safety hazard for the public and leave the building completely exposed.

Essential Components of a Weatherproofing Strategy#

A comprehensive strategy for temporary weatherproofing during recladding is not a one-size-fits-all solution. It must be tailored to the specific construction of the building and the type of cladding being replaced. At CladdingTesting.com, we advocate for a phased approach that keeps the building sealed at all times.

1. Breathable Membranes (WRB)#

Water Resistive Barriers (WRBs) are the most common form of protection. These membranes allow water vapour to escape from the inside, preventing interstitial condensation, while blocking liquid water from entering. In the context of recladding, these must be Class A1 or A2-s1, d0 rated to comply with the Building Safety Act and fire regulations for high-rise residential buildings.

2. Liquid-Applied Weather Barriers#

For complex geometries or interfaces where traditional membranes are difficult to seal, liquid-applied barriers offer a seamless solution. These are rolled or sprayed onto the sheathing board. They are particularly effective for cladding strip out weatherproofing because they can be applied quickly to the exposed substrate, providing an airtight and watertight seal that bonds directly to the surface.

3. Window and Aperture Encapsulation#

Windows are the most vulnerable points during recladding. The junctions between the window frame and the wall often rely on the cladding for final weather-tightness. During remediation, these junctions must be sealed with specialist flashing tapes or EPDM (Ethylene Propylene Diene Monomer) membranes to ensure rain does not bypass the frame and enter the apartments.

Managing Sequential Strip-Outs#

To minimise the need for extensive temporary facade protection recladding, many specialists use a "progressive" methodology. This involves stripping only as much cladding as can be re-covered or weatherproofed within a single shift. This "just-in-time" approach reduces the surface area of the building that is vulnerable at any given moment.

However, on large-scale projects, this is not always possible. Structural inspections or the need for extensive cavity barrier remediation might require large elevations to be exposed. In these instances, a full-height independent scaffold with debris netting or, in extreme cases, a full plastic "shrink-wrap" encapsulation may be required to keep the building dry.

Technical Challenges in High-Rise Weatherproofing#

High-rise buildings present unique aerodynamic challenges. The higher the building, the greater the wind pressure. Any temporary weatherproofing during recladding must be engineered to withstand these pressures. If a membrane is poorly secured, the "bellows effect"—where wind pressure fluctuates—can cause the material to tear or pull fixings through the sheathing board.

Fire Safety and Temporary Materials#

Following the Grenfell Tower tragedy, the UK has implemented strict rules regarding the combustibility of materials used on external walls. This applies to temporary materials as well. It is a common mistake to use flammable polythene sheeting for weatherproofing. We ensure that all temporary protection measures are non-combustible or of limited combustibility, maintaining the building's fire integrity even during the construction phase.

Thermal Performance and Resident Comfort#

For occupied residential blocks, removing cladding also means removing a layer of thermal insulation. Weatherproofing during cladding replacement must account for the sudden drop in the building’s U-value. If a building is left "naked" for months, heating bills for residents will soar, and the risk of internal surface condensation and black mould increases significantly. Temporary insulation or high-performance reflective membranes may be necessary to mitigate these effects.

Phases of Implementation: A Step-by-Step Guide#

Managing the weatherproofing process requires meticulous coordination between the façade engineers, the site manager, and the specialist contractors. The following steps outline the typical workflow for maintaining building integrity.

1. Pre-Commencement Survey: Assessing the condition of the existing substrate and identifying critical junctions (e.g., balconies, parapets, and vents).
2. Pilot Removal: Stripping a small area to confirm the substrate condition and test the adhesion of temporary membranes or tapes.
3. Zone-by-Zone Strip Out: Removing the old cladding system in manageable sections, ensuring each section is sealed before the end of the working day.
4. Application of Temporary WRB: Installing the breathable membrane or liquid barrier to the exposed sheathing.
5. Interface Sealing: Applying EPDM or specialist flashing to window perimeters and floor slab junctions.
6. Regular Inspection: Weekly checks of the temporary seals, especially after high-wind events or heavy rainfall, to ensure no breaches have occurred.

Integration with Cavity Barriers#

One of the most complex aspects of temporary facade protection recladding is working around cavity barriers. Cavity barriers are designed to stop the spread of fire within the wall cavity. Temporary weatherproofing must not obstruct the correct installation of these barriers. Often, the weatherproofing membrane is installed behind the cavity barrier, ensuring a continuous vertical seal that does not compromise fire safety protocols.

Common Pitfalls and How to Avoid Them#

Even with the best intentions, temporary weatherproofing during recladding can fail if technical details are overlooked. Property managers should be aware of these common issues:

• Incorrect Taping: Using standard duct tape instead of UV-stable, high-adhesion construction tapes leads to failure within weeks of exposure to sunlight and rain.
• Inadequate Lapping: Membranes must be lapped "shingle-style" (the upper layer over the lower layer) to shed water. Inverting this allows water to be directed into the building.
• Blocked Drainage: Temporary measures must not block the building's permanent drainage paths or "weep holes," which can cause water to pool in unexpected areas.
• Ignoring Vapour Permeability: Using non-breathable plastic sheets can trap moisture inside the wall, leading to rot in timber frames or corrosion in metal studs.

The Impact of Delay#

Façade remediation projects often face delays due to material supply chains or weather conditions. If the cladding strip out weatherproofing was only designed to last two weeks but the project is delayed by two months, the materials may degrade. Selecting high-quality, UV-resistant temporary products ensures that the building remains protected even if the project timeline extends beyond the original forecast.

Commercial and Financial Considerations#

While temporary weatherproofing during recladding adds to the initial project cost, it is significantly cheaper than the alternative. The cost of remediating water-damaged internal apartments—including replacing carpets, plasterboard, and furniture—can easily reach tens of thousands of pounds per unit. Furthermore, insurance claims for water ingress during construction can lead to spiralling premiums for building owners.

Professional managing agents should look for detailed weatherproofing specifications in any tender for recladding works. A quote that seems "too cheap" often omits the rigorous protection required to keep a building dry during the strip-out phase. At CladdingTesting.com, we provide comprehensive assessments to ensure that the remediation strategy accounts for all environmental risks.

Protecting the Investment#

Recladding is a major capital expenditure. The goal is to return the building to a safe, compliant, and high-performing state. Allowing water to ingress during the process undermines this goal. By prioritising weatherproofing during cladding replacement, building owners protect the long-term value of their asset and the well-being of their tenants.

Specialist Access and Logistics#

The method of access—whether it be mast climbers, cradles, or traditional scaffolding—will influence the weatherproofing strategy. For instance, mast climbers provide excellent access to specific areas but may limit the ability to install large-scale temporary sheeting across an entire elevation. Conversely, independent scaffolding allows for full-height debris netting, which provides a secondary layer of wind-driven rain protection.

In high-density urban areas like London, Manchester, or Birmingham, the logistics of temporary facade protection recladding are even more complex. Dust and water runoff must be managed to avoid affecting neighbouring properties or public footpaths. The weatherproofing system helps contain the site, ensuring that the "strip-out" remains a controlled environment.

Case Study: High-Rise Residential Remediation#

Consider a 20-storey residential tower requiring the removal of ACM (Aluminium Composite Material) cladding. The building is located in a coastal area with high wind speeds. A standard "strip and replace" approach would be too risky due to the weather.

The solution involved a phased strip-out using mast climbers. As each vertical "drop" of cladding was removed, a Class A2 fire-rated liquid weather barrier was immediately applied to the sheathing board. This provided an instant, airtight seal. Window perimeters were treated with a high-performance EPDM system. Despite a particularly wet winter, the building remained entirely watertight, and internal apartments suffered zero moisture ingress. This demonstrates the effectiveness of temporary facade protection recladding when planned correctly.

Frequently Asked Questions#

Is temporary weatherproofing mandatory during recladding?#

While there isn't a single law titled "Weatherproofing Act," building regulations and health and safety legislation require contractors to protect the building and its occupants. Failing to provide temporary weatherproofing during recladding would likely constitute a breach of the "duty of care" and could lead to significant legal and financial liabilities if damage occurs.

How long can a building stay in a "stripped" state?#

This depends on the quality of the cladding strip out weatherproofing. High-quality breathable membranes are typically rated for 3 to 6 months of UV exposure. Beyond this, they may begin to break down. If delays occur, these materials may need to be inspected and potentially reinforced or replaced to maintain protection.

Does the temporary protection affect the new cladding's fire rating?#

It can. If flammable materials are used for temporary protection and not removed, they could compromise the fire safety of the new system. It is vital that temporary facade protection recladding uses materials that are either removed entirely before the new cladding is installed or are themselves compliant with non-combustibility requirements.

Can residents stay in their flats during the weatherproofing process?#

Yes, most recladding projects on residential blocks are carried out while the building is occupied. Effective weatherproofing during cladding replacement is actually essential for resident retention, as it prevents the flats from becoming cold, damp, and uninhabitable during the works.

What happens if water gets behind the temporary protection?#

If water ingress is detected, it usually indicates a failure in the lapping or the taping of the membranes. The source must be identified immediately. This often requires a specialist inspection to check the seals around window heads and cills, which are the most common points of failure.

How does weatherproofing handle wind?#

On tall buildings, wind can create suction that pulls membranes away from the wall. To combat this, temporary weatherproofing during recladding involves using mechanical fixings (such as battening) or high-strength adhesives specifically designed for high-wind loads. The goal is to ensure the barrier remains static and does not flutter, which causes material fatigue.

Is insurance coverage affected by weatherproofing?#

Absolutely. Most "Contractors All Risks" (CAR) insurance policies require that the building be kept watertight. If a claim is made for water damage and it is found that temporary facade protection recladding was inadequate or missing, the insurer may refuse to pay out, leaving the building owner or contractor liable for the costs.

For any building owner facing the complexities of façade remediation, the importance of a dry, secure structure cannot be overstated. If you are concerned about the integrity of your building during an upcoming project, contact CladdingTesting.com for a professional assessment of your temporary weatherproofing during recladding requirements.