Exterior Cladding in March - What to Do While You Wait (and What to Leave Alone)

Expert Exterior Cladding
in March

What Exterior Cladding Is and What Can Go Wrong

Exterior cladding is the protective outer layer fitted over the walls of your home to keep rain, frost and wind from reaching the underlying structure. Systems fitted to residential properties include uPVC panels, fibre cement boards and timber boarding. When a cladding system fails, it is rarely the boards alone that are the problem. Moisture gets behind the panels, battens rot, membranes fail, and sealant at junctions breaks down. These failures tend to develop gradually, often invisibly, until a visible symptom appears.

We work on homes across March and the surrounding Fenland area, including Ely, Soham and Littleport. If you have spotted a problem with your cladding and are waiting for a contractor to survey or carry out the work, this page explains what you can sensibly do in the meantime, and what you should leave alone.

What to Do First When You Spot a Problem

The most useful thing to do immediately is document what you can see. Take clear photographs of the affected area from ground level. Note when you first noticed the problem and whether it followed a specific weather event such as a storm, sustained rain or a hard frost. This information helps any contractor understand the likely cause and the timeline of the damage, which in turn helps them assess how far the problem may have spread beyond what is visible.

Check internally in the room nearest to the affected area of cladding. Look at the wall surface, the skirting boards and, if you can, any insulation or cavity around that area. Internal damp patches, discolouration or a musty smell can indicate that moisture has already reached the wall structure. Make a note of anything you find. If you have a basic moisture meter, a reading on the internal wall surface in the affected area is useful to record and share with the contractor.

Temporary Protection: What Actually Helps

If a board has cracked or pulled away and is leaving the membrane or substrate exposed, and rain is forecast before a contractor can attend, some limited temporary protection is reasonable. A heavy-duty polyethylene sheet, secured carefully so it covers the exposed area and does not trap standing water against the wall, can reduce further ingress in the short term. The sheet needs to be fixed without causing additional damage: tape to sound boards rather than nailing or screwing into the wall, and check that the sheet will not catch the wind and pull away from the fixings.

This is a holding measure only. Sheeting does not fix the underlying problem, and covering an area with plastic reduces ventilation and can create conditions where condensation builds up behind the covering. Do not leave temporary sheeting in place for more than a few days before the proper work is arranged.

If sealant has failed around a window or door junction, a bead of exterior-grade sealant applied carefully to the joint will reduce water ingress until the full repair is carried out. Clear the joint of any loose or crumbling existing sealant first with a blunt tool, dry the area as well as you can, and apply the new bead in one continuous run. This is not a permanent repair but it is a safe, useful temporary measure that does not create further problems.

What Not to Do Yourself

There are a number of interventions that appear helpful but create additional problems or safety risks. Avoid these while you wait for professional work:

• Do not attempt to re-fix detached boards at height. Working on a ladder to nail or screw boards back in place is a significant risk of injury. It also risks damaging the membrane behind the board if you drive fixings through the wrong point, turning a repair job into a more complex one.
• Do not use expanding foam to fill gaps behind or between boards. Expanding foam is not a substitute for a correctly installed membrane and will prevent ventilation behind the boards. It also makes the area far harder to properly repair later, because the foam must be entirely removed before new material can be correctly installed.
• Do not apply exterior paint or coating over cladding that is showing signs of moisture damage. Painting over damp boards traps moisture inside and accelerates the deterioration. Surface coatings cannot fix structural problems, and they can obscure the extent of the damage from the contractor who comes to assess the job.
• Do not strip back cladding boards to see what is behind them unless you are prepared to cover the exposed wall immediately. Removing boards without having the materials and skills to seal the wall properly exposes the substrate to direct weather and can cause significant damage in a single rainy day.
• Do not pressure-wash the affected area. High-pressure water forces moisture into every crack, joint and gap in the system. In an area where the cladding is already compromised, this will drive water further behind the boards and into the substrate, worsening the damage before the repair has even started.

Understanding What the Repair or Replacement Will Involve

While you wait, it is worth understanding what the job ahead is likely to entail. This helps you ask the right questions when the contractor arrives and make sense of the quote you receive.

For a localised repair, the process typically involves removing the damaged boards, inspecting and drying the substrate behind them, repairing or patching any membrane damage, and fitting new boards with correct fixings and sealant at all junctions. Even a repair job requires the surrounding area to be inspected, because moisture rarely stays confined to the visibly damaged boards alone.

For a full replacement, the existing system is stripped to the wall, the substrate is inspected and prepared, a new breather membrane is fitted and correctly lapped, new battens are installed where needed, and the new boards are fitted from the bottom course upward with the correct overlaps, fixings and trim details. All junctions at windows, doors, soffits and roof lines are sealed before the work is considered complete.

Typical costs for exterior cladding work vary considerably. A targeted repair on a small area might cost a few hundred pounds. A full replacement on one elevation of a semi-detached house commonly falls in the range of £4,000 to £12,000 depending on the material, the size of the wall, access requirements and the substrate condition found once the old system is stripped. These figures are a general guide; a survey of your specific property is needed for an accurate quote.

Questions to Ask When the Contractor Arrives

You will have a limited window during the survey visit to gather the information you need. Use it. Useful questions include: what is the cause of the failure, not just what the symptom is; how far has any moisture ingress extended beyond the visible damage; what will be done to the substrate before new boards go on; and whether a repair or a full replacement is more appropriate given what they have found. Ask for these answers to be included in the written quote so that what you are agreeing to is clearly specified.

When to Treat It as Urgent

Most cladding failures develop slowly enough that a few days wait for a contractor is not critical. However, some situations do need faster attention. If a large section of boarding is loose and at risk of falling, particularly at any height above ground level, this is a safety issue that should not wait. If there is evidence of significant internal damp that is getting worse with each rainfall, this should be raised with any contractor as a priority when you call.

Get Your Cladding in March Properly Assessed

If you have spotted a problem with your exterior cladding and want an honest assessment of what it will take to put it right, call us to arrange a survey. We cover March and the surrounding area from our base in Ely, and we will give you a clear picture of what has failed, why, and what the proper fix involves before you commit to anything.