What Causes Skirting Boards to Rot?

Rotten skirting boards in Preston homes are almost always a sign of an underlying moisture problem. While skirtings themselves are simple to replace, the real issue is what’s happening behind them. If the moisture source isn’t fixed, the rot will return — and can eventually affect floor timbers, plaster and the wall base itself.

At Weather Wise Solutions Limited, we help homeowners in Preston identify the true cause of skirting board decay and provide long-term, reliable repairs.

💧 Why Do Skirting Boards Rot?

Skirting rot is never the problem — it is always the symptom.

Here are the most common causes we find in Preston properties:

1️⃣ Moisture at the Base of the Wall

If moisture is rising or tracking along the wall base, the skirting board absorbs it first.

Causes include:

damp masonry
defective pointing
porous brickwork
blocked cavities
leaking downpipes

Once the wall is wet, the timber begins to soften and rot.

2️⃣ Subfloor Dampness

Suspended floors rely on airflow beneath the boards.

When the subfloor becomes damp due to:

high external ground levels
poor ventilation
ruptured DPM
water ingress
internal leaks

…the moisture sits directly against the joists, floorboards and skirtings.
Wet rot can quickly develop in these conditions.

3️⃣ Bridging of the Damp Proof Course

One of the most overlooked causes of skirting decay.

Common examples include:

plaster touching the floor
debris or mortar in the cavity
dot-and-dab touching the floor
raised ground levels externally

If the wall is bridging, moisture bypasses the original DPC and soaks the internal skirting.

4️⃣ Incorrect or Inaccurate Damp Diagnosis

Many Preston homeowners replace skirtings, only to see the rot return months later.
This happens when the moisture source is not properly diagnosed.

Examples include:

treating salt staining as rising damp
assuming mould is the cause (it isn’t)
replastering without addressing the underlying defect
installing vents without moisture mapping

Only a full inspection reveals the true reason for decay.

5️⃣ Wet Rot in Adjacent Floor Timbers

If the skirting is decayed, floorboards or joists nearby may also be affected.

Wet rot thrives in damp, poorly ventilated conditions and spreads through timber in contact with the source.

🧰 How Weather Wise Fixes Skirting Rot in Preston

We take a structured approach to ensure the issue doesn’t return.

✔ Moisture Mapping & Diagnosis

Using calibrated equipment, we assess:

moisture levels in the wall base
humidity and vapour pressure
subfloor conditions
cavity bridging
salt contamination

✔ External Investigation

Checking:

pointing
brick condition
render
gutters and downpipes
ground level and drainage

✔ Subfloor Ventilation Improvements

If airflow is poor, we may recommend:

air bricks
telescopic vents
crossflow ventilation restoration

✔ Wet Rot & Timber Repairs

Replacing affected skirtings, floorboards or joists where required.

✔ Salt-Resistant or Renovation Plaster

Using specialist products from:

PAM Ties: https://www.pamties.co.uk/
Wycamol: https://wykamol.com/
Builders Super Store

✔ Long-Term Preventative Measures

Such as:

correcting ground levels
clearing cavities
removing bridging plaster
installing ventilation systems (PIV / DMEV)

We follow industry standards as members of:

Federation of Damp – https://federationofdamp.co.uk/
Damp Proofing Association – https://www.dampproofingassociation.co.uk/

Eligible works come with insurance-backed guarantees.

🏡 Why Preston Homeowners Trust Weather Wise

Weather Wise Solutions Limited is a family-run damp and timber specialist covering Preston and Lancashire.
We focus on accurate diagnosis, transparent advice and long-lasting repairs, never unnecessary treatments.

We are trusted on: