by neil-the-handyman »
Tue Sep 27, 2016 12:13 am
Hi,
I have been laying decking for years and can't for the life of me understand why I see it laid groove side up. The grooves, rather than is mistakenly assumed will provide grip, capture biomass, as part of the groove is always in shade it always remains damp and thus you have the perfect environment for algae/moss etc to thrive. If you think about it you also have less surface area so its bound to be slippier and its harder to clean. Aesthetically it just looks over-powering and unnatural. The moisture trapped by the grooves also upon freezing expands and becomes hazardous.
I always lay my deck with a 1:40 fall in whatever direction leads to sunlight (or away from linking pathways, ideally a flower bed). Thus any rain etc flows off and dries up naturally in the shortest possible time.
Sand can be used to provide additional traction. I recommend treating the surface on a hot spell with a decking oil. This allows the oil to be soaked into the wood and provide a permeable barrier promoting the water to run off thus reducing any issue.
The grooves underneath also acts as a drip tray thus preventing osmosis drawing the water between the decking boards and the carcass and trapping it. This reduces the biological attack and prolongs the life of the structure.