Browse Forums Outdoor Living 1 Aug 04, 2011 7:39 pm I have always been amazed at the differing responses to this question. There are 2 schools of thought. 1. Some people feel that the reeded side (the one with the grooves) goes up to provide a slip free decking. Fair enough school of thought ! I used to do it this way on all my decking projects. 2. Others feel that the reeded side goes down to provide the least surface area between the deck boards and the joists. This is meant to stop moisture build up and the boards rotting through at this spot. A neighbour of mine had decking on his balcony and after 10 years the timber had rotted through at that junction between deck board and joist (his timber was reeding up). He was pretty jacked off at the time and a builder told him the reasons outlined here. I can understand this thought process completely, but what do you think ? Re: Poll - Grooves up or down on decking ? 2Aug 04, 2011 7:58 pm I'm pretty sure they are suppose to go on faced down however my dad installed his face up (covered deck area) and I have to admit it looks good and also feels good underfoot Re: Poll - Grooves up or down on decking ? 3Aug 04, 2011 8:08 pm It's definitely reeds down. Face up you get more than a few issues: - The reeds will hold water for longer than the flat side, leaving the boards wetter for longer, potentially causing mould, distortion and cracking. - Nailing the reeded side is more likely to cause the boards to crack. - The reeded side only provides anti-slip properties when the force is perpendicular to the reeds. For force parallel to the reeds, you actually have less grip than the flat side. Re: Poll - Grooves up or down on decking ? 4Aug 04, 2011 8:11 pm I think down,how would you sand timber Re: Poll - Grooves up or down on decking ? 6Aug 04, 2011 10:43 pm Down down down, I seen One done like this today (upside down) it did look good tho. Re: Poll - Grooves up or down on decking ? 7Aug 05, 2011 12:56 am I went the reeded side up when installing my jarrah decking (105x30 for the enthusiasts ). Its sitting under a bullnose verandah and i have a fall of about 20mm over the 2400mm length. Its well protected from the south westerly rains but it certainly gets wet throughout the year. been down 8 years now and still looks good, no rotting, just apply some oil each year and still going good. Re: Poll - Grooves up or down on decking ? 9Sep 22, 2011 1:53 pm Good! I don't like the look of the grooves at all and imagine how the water ater rain would pool in the grooves and weather much more easily. Thank goodness for this site! Our deck is getting done ATM! Re: Poll - Grooves up or down on decking ? 11Sep 22, 2011 2:05 pm I'm going to check before they got laid and get them laying face down. Thanks Libby. Re: Poll - Grooves up or down on decking ? 12Sep 22, 2011 8:28 pm I laid my decking reed-face UP on an arched bridge over a feature pond to avoid it becoming slippery when wet from the fountain, but I have seen it laid both ways on a flat deck Arfur Re: Poll - Grooves up or down on decking ? 13Sep 23, 2011 9:53 am grooves down! Our previous house had grooves up merbau, what a waste. Not only did everything underneath rot through but it was painful to walk on after a while. The boards also had cracks from the nails as well. Definitely go grooves down from now on. Re: Poll - Grooves up or down on decking ? 14Sep 24, 2011 9:46 am There was some guy on the ABC radio this morning talking about decking/pergolas etc... this was one of the questions.... and they guy (not sure who he was) said the grooves should go down. HHCIB Re: Poll - Grooves up or down on decking ? 17Sep 26, 2011 9:00 am Huggy_B buy decking boards with no grooves - problem solved. Not quite. The grooves are there to stop the decking rotting out where they rest on the joists. So you would be creating a problem, not solving one. Re: Poll - Grooves up or down on decking ? 18Sep 26, 2011 9:51 am eyspy Huggy_B buy decking boards with no grooves - problem solved. Not quite. The grooves are there to stop the decking rotting out where they rest on the joists. So you would be creating a problem, not solving one. No offense, but what a load of codswallop. This whole airflow thing is a load of crap - how much air is gonna flow through those piddly little grooves? And how likely is that to stop rot? Not likely at all. If you are that concerned about your joists or boards rotting, then put a primer on the joists or put a physical barrier bewteen the joists and decking boards. Re: Poll - Grooves up or down on decking ? 19Sep 26, 2011 8:22 pm Have had both (grooves up where on house previous to us buying and we add grooves down) And there was a huge difference between the two!!! The grooves up ended up a big eye sore and rotted not to mention that previous owners had painted it and it was really hard to repaint into all those gooves again (not a good look) not to mention all the dog hair that got caught in there Yukko. The gooves down still, to this day looks great, easy to restain, and has nice clean lines. Re: Poll - Grooves up or down on decking ? 20Sep 26, 2011 9:20 pm Huggy_B eyspy Huggy_B buy decking boards with no grooves - problem solved. Not quite. The grooves are there to stop the decking rotting out where they rest on the joists. So you would be creating a problem, not solving one. No offense, but what a load of codswallop. This whole airflow thing is a load of crap - how much air is gonna flow through those piddly little grooves? And how likely is that to stop rot? Not likely at all. If you are that concerned about your joists or boards rotting, then put a primer on the joists or put a physical barrier bewteen the joists and decking boards. Not codswallop. When you have ripped up as many decks as I have you see the difference. Putting a primer or physical barrier between the joist and the decking board ONLY protects the joist, moisture will still be on the underside of the decking board. Those "piddly little reeds" do make a massive difference. Hi, as per the subject. Does anyone have any recommendations for the best value decking oil (Bunning is close to where I live) for a treated pine deck? Thanks 0 10971 Use a product like Equisol's Vitalise to clean the deck then coat with a penetrating timber oil. It will look 10 years younger and add value to your home. Visit for… 1 15774 Hi, Really struggling to find some consistency amongst Span Tables, can anyone help… 0 2658 |