Rising damp

How to Install Dryrod® Damp-Proofing Rods


Required: SDS Drill, 12mm Drill bit, Tape Measure, Nitrile Gloves

Other useful tools: Dryrod® Hole Clearing Tool, Dryrod® Cutters


Dryrod® preparation.

Mark your drill bit to the appropriate depth for the wall you wish to treat. A Dryzone 12mm Drill Bit is recommended for enhanced debris removal. Set your SDS drill to rotary hammer mode and attach the suitably marked drill bit.


Dryrod® drilling guide.

Identify the lowest horizontal mortar course that is accessible and continuous. Drill holes to the full recommended depth, at regular 120mm spacing along the wall. As the drill bit approaches the final 40mm of the intended hole depth, make sure to reduce the pressure you are putting on the drill. Excessive drilling pressure on the rotary hammer setting can result in damage to the far side of the wall

Where the mortar is fully saturated, it may have begun to degrade, meaning that drilling dust can clump together and not clear the hole properly.

If this debris obstructs the insertion of the damp-proofing rods, re-drill the holes twice to remove any excess material.

If debris continues to obstruct the full rod insertion, the Dryzone Hole Clearing Tool can be used to ensure the hole is completely clear.

Recommended Drilling Patterns

Stretcher bond drilling pattern.

Stretcher Bond

In stretcher bond construction the mortar joints fall at approximately 12cm intervals and can be used to quickly locate your drilling points.

Flemish bond drilling pattern.

Flemish Bond

In flemish bond construction the vertical mortar joints either side of the smaller bricks and rthe mid point of the larger bricks lie at approximately 12cm intervals and can be used to locate your drilling points.

Irregular stone drilling pattern.

Irregular Stone

In irregular stone construction drilling points must be measured and care must be taken to make sure the line of the rods follow and unbroken line through the mortar at 12 cm intervals.

Damp-Proofing Rod Insertion

Dryrod® damp-proofing rod insertion.

Wearing suitable gloves, remove the rods one by one from the packet and fully insert them into each hole. Ensure the rods are recessed approximately 5mm from the brick face, taking care not to compress the rod.

When installing internally, the performance of the rod will not be affected if the rods protrude slightly from the mortar, as a result of it being eroded at the surface. As long as the rod is inserted to the correct depth at the far side of the wall, full treatment will be accomplished and any protruding rods will be covered during redecoration.

Cutting & Combining for Walls Thicker or Thinner than 9”

A standard Dryrod® Damp-Proofing Rod is 180mm in length, which is the exact length required to treat a standard 9” wall.

Dryrod® length for 9 inch walls.


If the wall is thinner than 9” then cut the rods down until they are 10mm shorter than the length of the hole.

Dryrod® length for 4 and a half inch walls.


Dryrod® length for 4 and a half inch walls.

If the wall is thicker than 9”, cut a second rod down till its length is 10mm less than the excess left after inserting one whole rod.

Dryrod® length for thirteen inch walls.



Number of rods required per 10m stretch of wall

Wall depth 4½" (110 mm) 9" (220 mm) 13½" (330 mm) 18" (440 mm)
Rods per 10m 42 83 125 166

Further Technical Advice

If you have any further technical enquiries or have further questions about the installation process, feel free to call our technical team on 01403 220110.