Browse Forums Landscape & Garden Design 1 Oct 08, 2011 1:35 pm Hi all, We're almost at the point of finalising our plans and aren't sure what do about our alfresco and verandah. We want both to be decked which needs to be post-handover with our builder. We want the decking to be a really firm surface. Every time we've asked about display home decking we've liked, we've been told it was built on top of concrete, so we planned to get our builder to concrete the alfresco and verandah in preparation for decking (plans in signature link). Yesterday I asked advice from a decking company to ensure we've got the concrete levels right, but they said not to concrete it as it will reduce the lifespan of the decking due to lack of drainage and ventilation. Now I know you *can* build decking over concrete because I've found a number of threads here saying as much (and Stormy's beautiful pictures). What we want to know is whether it's actually advisable? - and if so: what's the optimum amount of space to leave for decking (i.e. how much lower should the concrete be than the final decking floor level)? - but if not: how else do you get a super-firm decking floor? Thanks in advance Anise Build thread: /viewtopic.php?f=31&t=49109 Blog: http://thelofthouse.wordpress.com/ Re: Best ground for firm decking - to concrete or not? 2Oct 12, 2011 12:23 pm We decked over concrete on our front porch. We still used 'joists' that we dynabolted into the concrete spacing them about 450mm apart and I think they are about 180mm high (they are rectangular shaped wood and we ran them on their side to give us the height) We made sure that there was a thin gap along the front between the bottom decking board and the concrete to allow any moisture to run out, and there are small gaps between the decking boards (which we didn't space apart but being pine they have shrunk slightly to give about a 1mm gap). As long as there is correct slope on the concrete underneath you should be right. I don't see how this set up would be any worse than having piers into the ground, as the ground would likely be damp underneath anyway. The main reason we decked it was because the concrete porch was part of the house slab, so it was already done, and didn't match the exposed agg of the driveway and path. We also considered the same for our back patio and settled on using concrete because a) we can use the concrete in the mean time until we get around to the decking, and b) where we live doesn't require a council permit ($400) to deck if it is on a concrete foundation, but we do if it's over 10m2 with bearers and joists (which also cost more than the concrete). As mentioned we used treated pine for our decking, and there is a little give in it, but I would think using merbau or another kiln dried hardwood would create a firmer walking surface. All the best with your decision. Second Time 'Round Re: Best ground for firm decking - to concrete or not? 3Oct 12, 2011 3:46 pm Our deck is on steel stirrups off concrete piers at 1200mm centers. After five years its still rock solid. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Best ground for firm decking - to concrete or not? 4Oct 18, 2011 11:29 pm thanks for the feedback I think we've decided to leave the concrete off the build for now. They were going to do it afterwards at the same time as the garage so not part of the engineered slab or owt anyways, so this way we can change our minds down the track when we're ready to do the decking and decide then how to approach it. Build thread: /viewtopic.php?f=31&t=49109 Blog: http://thelofthouse.wordpress.com/ 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 Hi everyone, Looking for some advise. We are about to build an above ground pool in our backyard. There is a private sewer line running under the pool at 1.6m… 0 11759 Hi, I'm new to this forum so I hope I'm doing this post correctly. Please advise if it's not. I've just bought my place. The inground pool has a marble lining that has… 0 13663 |