Wanstone Rediscovered, White Cliffs of Dover - Protecting Heritage Structures with Stormdry Masonry Protection Cream

In the early 1940s, two 15-inch naval guns, No 1. code-named Jane and No. 2 named Clem, jutted out into the sky over the White Cliffs of Dover. The Wanstone gun battery was capable of striking Axis targets across the Dover Strait and even to mainland France. Four brick-built, earth-covered ammunition magazines (ECMs) fed massive shells into each 15-inch, 100 ton gun and housed the ammo stockpile.

After the war, the guns were decommissioned and the structures were left to the elements. Decades of unprotected exposure caused weather damage to the four buttress walls that supplied ‘Jane’ with ammunition. Volunteer teams from the National Trust’s Wanstone Rediscovered project, funded by the National Lottery Heritage Fund, got to work after the National Trust acquired the land in 2017.

They stripped vegetation, rebuilt damaged sections and prepared the various structures of the Wanstone gun emplacements for long-term protection. Wanstone Rediscovered Project Manager Jon Barker and his team aimed to stop further moisture damage as part of a larger effort to restore the site with a view to eventually opening it to the public.

A salt-laden sea breeze races across the Dover Strait, driving rain straight into the exposed brickwork magazine entrances. Repeated wetting, freeze-thaw cycles and invasive plant growth had caused the brick faces to spall. In spring 2023, specialist brick experts were tasked with replacing the destroyed yellow stock and fletton bricks. After carefully matching replacements, they painstakingly got to work restoring the walls back to their former glory. Among other works, ties and additional water drainage measures were also installed.

The coastal location required careful consideration of the possibilities of crypto efflorescence, which occurs when soluble salts migrate to the surface and crystallise, causing delamination of the brickwork. With the site just a stone’s throw away from the Strait of Dover, salt exposure was potentially a risk here.

In June 2025, the Safeguard Technical team visited Dover with over 80 litres of Stormdry Masonry Protection Cream. Thanks to the combined effort between Safeguard and the National Trust volunteer team, Stormdry Cream was applied to all four buttress walls on Jane’s two magazines in a single day.

Prior to that day, the volunteer team treated each magazine buttress wall with SoluGuard Multi-Surface Biocide, a ready-to-use, water-based treatment formulated to remove algae and fungal growth.

The treated surface as cleaned after 72 hours with a low-pressure water spray then allowed to dry before Stormdry Cream application. On application day, the team used long-handled block brushes to remove any mortar debris and dust, then it was time for Stormdry Cream. The team used thick-pile masonry brushes to apply a single layer of Stormdry Cream to each magazine buttress. The unique protective formulation absorbed into the yellow stock and fletton brick wall to form a breathable siloxane network that repels rain and water while allowing vapour to escape; this attribute is essential for the preservation of heritage structures. The treated surfaces were shower-proof one hour after application and now enjoy a full 25-year service life - BBA certified. Stormdry Cream’s invisible finish ensured that the magazine walls retained their original wartime character while protecting them comprehensively from water ingress.

Stormdry’s one-coat, cream-based formulation proved ideal for a volunteer-led heritage site: no specialist equipment is needed and the application process is straightforward and relatively fast.

The Jane gun’s magazines at Wanstone are now one step closer to being ready to greet visitors, where they will hopefully be as dry, stable and formidable as the day they fired those first shots across the Channel.

But this is a massive project, and there’s still work to be done…

Now that Jane has been protected, it’s Clem’s turn. Over the coming months, the team will apply Stormdry Masonry Protection Cream to the four buttress walls of each of the two Clem magazines. This will complete the magazine restoration part of the overall project, protecting both structures for many years to come, giving the team a chance to rejuvenate other elements of these incredible structures.

Want to see the Jane and Clem in person? Keep an eye on news of the next open days and follow the latest developments from Wanstone Rediscovered here