Concrete posts and gravel boards are what saves a Deal fence line long-term. A timber-post boundary on the Kent coast has a ground-line rot-clock that starts the day it goes in, and every winter easterly accelerates it. A concrete-post retrofit - pull the rotten timber posts, drop in concrete morticed replacements, add a concrete gravel board along the base - buys the fence line another twenty years without touching the panels or boards above.
When retrofit makes sense
Retrofit makes sense when the panels or closeboard above are still sound but the posts have started to move. The tell-tale is a fence line where the panels are fine but every third or fourth post is now leaning under wind load, or where you can wobble a post at the base with a hand-push. On a run of 12 panels with 6 to 8 failed posts, a concrete-post retrofit is roughly 40 to 50 per cent of the cost of a full fence replacement and gets you the same forward life.
Chalk substrate on Kingsdown
Kingsdown and Ringwould post-holes hit chalk at 200mm to 300mm. Standard hand-digging is not practical. Post-holes are augered with a petrol auger - a slower operation than digging into loam, and the reason Kingsdown post-set jobs quote higher per-post than the same job in Sholden. Post depth is 750mm minimum on any Kingsdown clifftop plot.
Concrete gravel boards
A concrete gravel board along the base of the fence line keeps the timber above the wet-ground zone. On coastal boundaries this is the single most important detail against ground-line rot - the featheredge boards or panels above sit on top of the gravel board, not in the wet grass, and the whole boundary lasts significantly longer.
How pricing works
Per-post retrofit installed, and concrete gravel boards supplied and fitted, both quoted from photos. Full concrete-post-and-gravel-board conversion on an existing fence line typically comes in at 40 to 50 per cent of the cost of a new fence, and gets you the equivalent forward-life.
Quote from photos. Send a couple of photos and a postcode to WhatsApp on 07763 100 477 or use the quote form. Fixed price on straightforward runs.