Walls Dry and Wet Rot Proofing

Treating dry and wet rot

Instruct a competent contractor, for example from the Property Care Association (formerly the British Wood Preserving and British Chemical Damp Proofing Association) to carry out a detailed diagnostic inspection of the property to identify all the areas affected by the dry and wet rot. The inspection should:

Carefully inspect all timbers, removing skirting’s, floorboards, masonry, etc to determine the extent of the infection. Test for fungal decay by prodding timbers with a screwdriver or similar instrument and carefully examine to assess depth of decay in any large dimension timbers.

Inspect plasterwork adjacent to decay for signs of fungal strands/mycelium. The extent of growth can be determined by removal of plaster samples. Strip off any plaster containing or suspected to contain the fungus; also examine the mortar courses for fungal growths. Flaking, bulging and damp patches and plaster should also be investigated.

Inspect cavity wall for spread of fungus by removal of random bricks to provide access.

Check ventilation to timber suspended floors and improve if necessary.

This inspection shall be followed by the submission of a report that details both the cause of the decay and the proposed remedial action. Forward a copy of this report to the case officer at the Council. Undertake the remedial action outlined in the report. In particular the following shall be undertaken:

Identify and locate sources of moisture ingress and carry out measures to prevent this water ingress. The property must be dried rapidly through the provision of heating and ventilation, introduce space heaters if necessary.

Cut out and remove from site all decayed timbers together with a margin of up to 600mm beyond the last evidence of fungal decay; the actual amount removed will depend upon the extent of decay and the site conditions.

Replace rotten timbers with treated timber, and treat all remaining timbers with an effective fungicide.

Contain the fungus within the masonry away from potential food sources as follows: a. Physical containment: joinery lining around adjacent timbers; b. Fungicidal renderings and paints: these effectively form chemical barriers. c. Masonry sterilization: This involves the application of a special water based fungicide to the masonry.