Browse Forums Outdoor Living 1 Apr 08, 2015 3:55 pm We are just preparing to build a 25sqm Deck and due to conflicting advice are unsure what size boards to use as we want to avoid the chance of cupping. The deck/verandah will be about 1 meter off the ground and we intended to use 140mm Kiln Dry Merbau. We can get 140mm x 22mm at Bunnings but another supplier has said that to avoid cupping I would have to buy 140mm X 25mm which of course they supply. The last supplier said that only a minimum 25mm would stop cupping. The reason we are going with 140mm inlieu of say 90mm is that the deck/verandah is straight off a 1904 Federation home that has the old fashioned wide floor boards. Any and all advice would be appreciated. Also has anyone had any problems with Merbau. We live at Maitland (NSW). Also any recommendation for an alternate material ?? Re: Deck Cupping 2Apr 08, 2015 5:43 pm I would think cupping has less to do with the size of the timber and more to do with h how it is installed and more importantly protected. The reason it cups is related to moisture so I think keeping moisture out is the key. Sent from an elegant mobile device using Tapatalk. The Blog for my new house build is http://customaussie.blogspot.com.au and my forum thread is at viewtopic.php?t=74944 Re: Deck Cupping 3Apr 09, 2015 9:59 pm Keep width of board no more than 4x the thickness Ensure good ventilation below deck as cupping is a moisture difference between the top and underside of board. Australian hardwood like spotted gum or iron bark would we best choice Re: Deck Cupping 4Apr 14, 2015 3:26 pm Another major factor on top of moisture is the fasteners used to install the decking. Using nails is a big no no considering it'll rip it right up. No nail decking is in the iffy category considering a single screw is trying to prevent two boards from prying up at the most prone of areas. Using 8g screws on a board will do the same. Therefore, 10g screws provides a pretty good hold. Once again, screwing into pine will also increases the chances of prying up where as screwing into hardwood would make it pretty solid. Food for thought. I've just built 3 stairs off a landing out the back and been told by the private certifier I need hand rails sorry tried to attach a pic but couldn't mine don't have sides… 5 5835 So I'm just reading up on this ecosystem of lights. I'm planning on putting deck lights along the outside edge of a large deck. Will need about 3 packs (18 lights) plus… 0 23195 Hi, does anyone have any experience with using Trex rain escape or EPDM rubber to waterproof a deck so you have dry space underneath. Popular in the US and realize that… 0 3511 |