1940s Concrete Pillbox, West Sussex — High-Performance Waterproofing with Stormdry Masonry Protection Cream

A lone concrete box has stood on Ferring seafront for over 80 years, slowly succumbing to the endless onslaught of seawater, wind and rain. Still, it’s been an easier life than the one it was built for — to hold back an invasion during World War II.

8000 guard-post pillboxes were built across the British coastline in the late 1930s-early 40s. Worthing Rural District Council removed 27 pillboxes from Sussex following the end of the war in 1945. The Lancing pillbox was later buried, leaving the Ferring example as the last one standing.

Built in Summer 1940, the Type 26 pillbox is a 6 ft by 6 ft cube just big enough to house 4 soldiers and their guns. The 1 m thick concrete walls were built to withstand a direct hit from a naval warship. 98 tons of concrete went into creating the pillbox. In the 1980s, the whole exterior was covered in a pebbledash (sometimes known as roughcast) finish that was applied in the 1980s to preserve the structure.

The pillbox lacked a door, so the original tiny entrance was first sealed up with brick, then replaced with a metal door in the early 1980s. The open gun embrasures were also concreted over. Although these measures modified the original appearance of the site, they were necessary —  many surviving open pillboxes have since been vandalised.

The Problem

In direct view of the sea, the area is susceptible to wind-driven rain at speeds of up to 70 mph. The pillbox is only 25m away from the water’s edge and stands on a concrete podium deck. Exposure to saltwater spray left salt deposits on the exposed sea-facing side of the rendered surface.

The Ferring History Group and Ferring Conservation Group project team gained access to the pillbox in July 2023. A team effort saw 9 inches of rainwater returned to the sea, and soon after the south-side gun embrasures were opened up to accelerate the interior’s drying out process. 

The restoration team removed the concrete from the sea-facing gun embrasure and metal gates were installed to allow the original opening to be displayed during open days. To keep the pillbox secure, the east and west embrasures will remain sealed.

Inside, our investigation found evidence of condensation on the ceiling. The internal timber steps were also damp and rotten. For the Safeguard technical team, stopping future water ingress and preventing any further moisture-related damage to the exterior of the pillbox was the goal. Because of this project’s historical importance, any waterproofing treatment would have to be completely invisible once cured.

The render finish was in fair condition for its age. However, there were several signs of cracking across its structure, especially on the land-facing side. These cracks were mostly under 0.6 mm in width, but needed to be bridged to prevent water ingress. Some pebbledash had fallen off over time to expose bare concrete.

The Solution

The exact composition of the pillbox’s concrete render was not officially recorded, so the Safeguard R&D Laboratory first carried out in-depth analysis to identify the right waterproofing treatment for the job.

In the Lab, a small sample of render taken from the bottom of the pillbox was split into two. Both pieces were cleaned with SoluGuard Multi-Surface Biocide, then left to dry for 24 hours.

The Safeguard R&D team removed biological growth with a brush, then applied Stormdry Masonry Protection Cream to one of the samples. The samples were left for 5 days to cure, then placed on a sponge and submerged in water.

Stormdry Masonry Protection Cream successfully stopped water absorption, when compared to the untreated sample. It was approved for the Pillbox application due to its unbeatable waterproofing performance and invisible finish.

First things first: 84 years of grime and biological growth had accumulated on the surface of the pillbox. The team applied SoluGuard Multi-Surface Biocide to the pillbox walls and roof with a pump-action sprayer to remove algae and fungi growth.

In October 2023, the restoration team applied small squares of Stormdry Cream to the south and west elevations, as well as the flat roof. Stormdry Gauge testing in April 2024 confirmed that Stormdry Cream successfully waterproofed it throughout the harsh winter.

The team also undertook a full check to ensure that Stormdry Cream had successfully absorbed into the substrate. 

A repair mortar was used to fix the bigger cracks in the render, while Stormdry Cream took care of the smaller ones. Stormdry Cream penetrates to a crack-bridging depth of up to 12 mm to seal small defects. 

On a rare sunny day in July 2024, the volunteer team, armed with wide painter’s brushes, arrived at the pillbox. It took the team of four less than two hours to cover the entire 48.5m² structure in the one necessary coat of Stormdry Masonry Protection Cream. Now that the exterior of the Ferring Pillbox is fully waterproofed and protected from penetrating damp for 25 years, people can come and visit this piece of history for years to come.

For more information about Ferring History Group, visit: https://www.ferringhistorygroup.co.uk/