--- title: "Composite Decking Replacement in Whetstone N20 | CLEO M Gardening" description: "Composite decking replacement on a glass-balustrade terrace in Whetstone N20. Rotted timber stripped, sound joist sub-frame retained, light composite boards re-laid with concealed fixings. Project budget around £5,000. Photos and detail from CLEO M Gardening." url: https://cleomgardening.co.uk/projects/composite-decking-whetstone-n20/ --- [Home](/) › [Projects](/projects/) › Composite Decking, Whetstone N20 # Composite Decking Replacement in Whetstone N20 Rotted timber stripped and replaced with light composite on a glass-balustrade terrace Location **Whetstone, N20, London** Completed **March 2026** Service **Decking** Budget **Up to £5,000** ## The Brief A first-floor terrace in Whetstone N20, framed by a clean glass balustrade and accessed off the rear bi-fold doors, had a timber deck that had rotted out over the years. Several boards had cupped, a few were soft, and the moss in the grooves was permanent. The homeowner wanted a like-for-like replacement that would hold up properly outside and not need re-treating every spring. ## What We Did * **Stripped the old timber boards** from the full terrace and pulled the last of the rotted fixings. * **Inspected the existing joist sub-frame.** Most of it had stayed sound under the failing boards, so we kept the structure in place and only replaced a small number of timber bearers where the moisture had got into the end-grain. * **Re-laid the terrace in light composite boards**, set with concealed fixings so the finished surface reads as a single uninterrupted run. * **Trimmed cleanly around the glass-balustrade posts and the threshold** at the bi-fold doors so the finished line sat flush with the existing detailing. * **Removed all debris** and left the terrace ready to use. ## The Result A clean, low-maintenance terrace surface that will outlast any timber alternative without the annual oiling cycle. Composite holds its colour, doesn't splinter, doesn't host moss in the grooves, and is comfortable underfoot in bare feet through the summer. The homeowner gets back their main outdoor space at the back of the house, finished to a standard that matches the modern glass-balustrade architecture it sits with. **Job duration:** Roughly one working week on site, including the strip-out and the new lay. **Budget:** Up to £5,000 for the full terrace, materials and labour included. ## Gallery ![After: light composite decking on a glass-balustrade terrace, replacing the old timber](/pictures/projects/composite-decking-whetstone-n20/whetstone-01-after-hero.webp) ![After: finished composite decking, alternative angle showing the full terrace](/pictures/projects/composite-decking-whetstone-n20/whetstone-02-after-wide.webp) ![During: stripping the old rotted timber decking boards](/pictures/projects/composite-decking-whetstone-n20/whetstone-03-during-strip.webp) ![During: exposed timber joists after removing the old deck](/pictures/projects/composite-decking-whetstone-n20/whetstone-04-during-joists.webp) ![During: laying the new composite boards onto the cleaned joist sub-frame](/pictures/projects/composite-decking-whetstone-n20/whetstone-05-during-lay.webp) ![During: composite boards partway through install, with the remaining old section visible](/pictures/projects/composite-decking-whetstone-n20/whetstone-06-during-partial.webp) ![Detail of the finished composite boards and concealed fixings](/pictures/projects/composite-decking-whetstone-n20/whetstone-07-detail.webp) ![Before: rotted timber decking with moss and missing boards on a glass-balustrade terrace](/pictures/projects/composite-decking-whetstone-n20/whetstone-08-before.webp) × ❮ ❯ 1 / 1 ## Replacing Tired Decking? Message Clement on WhatsApp or call 07958 330070 for a free quote on composite decking across Whetstone, Barnet and North London. [Get a Free Quote](https://wa.me/447958330070?text=Hi%20Clement%2C%20I%27d%20like%20a%20free%20quote%20for%20a%20composite%20decking%20replacement.)