Closeup of wet rot damaged timber beams

Wet rot found in a church in Lancashire

13 June 2019

Built in the late 17th century, this timber frame church was built to serve the growing population of Lancashire. Once a physical representation of the thriving industry and prosperity of the area, the church had recently fallen on to hard times and fell into disrepair.

With the recent storms sweeping across the North of England, the church was left open and vulnerable to the elements. Concerned over the future of the church’s structural integrity, the parish called upon Timberwise to identify, and treat, a possible wet rot outbreak.

Did you know?

As well as wet rot there is one more common form of fungal decay – dry rot. Although both can cause structural damage to buildings wet rot, however, tends to grow on porous surfaces such as timber with a moisture content of around 30% while dry rot can grow with as little as 20%.

What is wet rot?

Wet rot is a generic term given to the natural decay found in timber due to the high presence of moisture. There are many types of fungal species; these fungi draw their food from the walls of wood cells. Wet rot can only grow where timber is present and is commonly found in joist ends, skirting boards and external joinery.

How do I identify wet rot?

Wet rot can be identified with a few common tell-tale signs. The timber will have a brittle texture and will start to breakdown and crack, the floorboards will be weakened and a damp musty smell will be present. The fungi found in the church can be divided into two types, brown rots and white rots.

Brown Rot (Paxillus panuoides)

This brown rot targets very wet softwoods and spreads over damp timbers. The rot destroys the cellulose in the timber causing it to darken in colour. The photos show the brown rot in situ and the fruiting body in greater detail.

Brown rot type Paxillus panuoides - fruiting body











White Rot (Donkioporia expansa)

This rot feeds on hardwoods such as oak and digests cellulose and lignin within the timber. This results in a lightening of the decayed timber.

CLose up of Paxillus panuoides fruiting body











How do I treat wet rot?

The first step in wet rot treatment is to identify the source of moisture and remove it. In this case, the leak was due to defective rainwater goods along with a combination of high rainfall.

The timber then needed to be dried out, Timberwise Technicians cleaned and dried out the timber infected with wet rot from the heavy rainfall. Timberwise Technician’s then removed timber that was structurally unsound. These weakened timbers were identified due to the cracked (cuboidal) crumbling appearance. By completely replacing the timber this prevents further spread of the rot. It’s crucial that the wet rot is identified as early as possible, the longer the problem is left the worse it can become.

What should I do if I discover wet rot?

This ensures the structural integrity of the building. Specialist wet rot treatment is then required to finish off the process.  This generally involves eradication through the chemical spray and other wet rot treatments. To arrange a survey for identifying the signs of wet rot call our team on 0800 288 8660 or complete our on-line wet rot survey request form.

Originally published 1st March 2012, updated 13th June 2019.