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Lignum Masonry Biocide ProM50 1L

100% of 100
£18.50 Ex VAT
£22.20 Inc VAT

A high strength fungicidal microemulsion concentrate for the treatment and control of dry rot and fungal growth in masonry.

Dry Rot Treatment for Masonry & Brickwork - Concentrate

Dry rot in masonry can be a serious problem. With rapid absorption and excellent penetration, this masonry biocide stops the spread of dry rot in all types of masonry and brickwork.

Treating Dry Rot in Masonry

As a high strength fungicidal microemulsion concentrate, it is designed for deep and even penetration into the substrate. This ensures longer lasting protection against dry rot and fungal growth in masonry.

Dilutable with water, this concentrated masonry biocide is specially designed for professional use. It is suitable for spray application or injection into the masonry. It can also be used as a subfloor over site steriliser where necessary in areas of dry rot out-breaks. It can also be used in gauging water for the re-rendering of treated masonry or brickwork. 

How Masonry Biocide Treats Dry Rot

Microemulsion technology enables the biocide to penetrate deep into the masonry or brickwork, delivering the active ingredient IPBC (3-Iodo-2-Propynyl Butyl Carbamate) with rapid rates of absorption. The biocide then targets the fungus, stopping it from spreading.

How to use Masonry Biocide

Follow these steps to eradicate dry rot from masonry and brickwork:

  1. The first step is to identify and rectify the cause of dampness associated with the dry rot outbreak. There are a number of reasons for dry rot including leaking gutters, poor ventilation, and rising damp.
  2. Determine the extent of the dry rot outbreak. You will need to open up the affected area to identify the infected timbers.
  3. Once you have identified the infected timbers, it is recommended that you cutback the timbers in-situ to 500mm beyond the last signs of fungal growth or strands.
  4. Remove plaster and render in all directions.
  5. Clean the wall area to remove surface growth and strands. A stiff brush can be used on the walls if required.
  6. You are now in a position to spray, brush or inject the masonry biocide. For surface sterilisation, saturate surface of wall using a course spray.
  7. Where fungal growth is extensive i.e. penetrated the wall structure, then irrigate the wall through holes drilled two thirds of the wall depth at staggered 230mm centres and at a downward angle into the mortar beds so as to ensure full penetration.

Coverage :

Dilutution: 1L + 24L water to give 25L of ready to use Masonry Biocide

Coverage may vary with the properties of the substrate but these are guidelines:

Surface Spray: (1 - 2 coats) 1 litre of diluted product per 5m² of surface

Irrigation: 10 litres of diluted product per 1m3


Further Reading: Read our How to Get Rid of Damp Guide to find out the cause of the dampness and find out ways to improve ventilation.




  • Specially formulated for the eradication of dry rot in masonry & brickwork
  • Provides deep and even penetration ensuring long term protection
  • Microemulsion water based formulation
  • Zero VOC’s
  • Quick drying
  • Non-flammable
  • BS EN Standards
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