Browse Forums Building Standards; Getting It Right! 1 Jan 08, 2020 1:10 pm Hi Our decking which was installed about 6 months ago has issues with the joists splitting. This has caused some screws to pop up as the screws won't stay down. Nearly all the joists have split, some from where the decking screws were off center from the joists and some are centered but split. I assume the wrong size holes were drilled. The joists also don't have a rubber joist protector which has likely made this worse. The contractors have agreed to change some of the joists (outer decking), but not all. They say the others are just surface splits and they aren't an issue. I assume they are trying to avoid taking the whole length of the decking up. I can't find any standards in regards to screws having to be centered in joists, and how wide a split has to be to be covered by AS. Any help much appreciated. Cheers Re: Decking joists splitting 2Jan 08, 2020 9:24 pm alexf40 Hi Our decking which was installed about 6 months ago has issues with the joists splitting. This has caused some screws to pop up as the screws won't stay down. Nearly all the joists have split, some from where the decking screws were off center from the joists and some are centered but split. I assume the wrong size holes were drilled. The joists also don't have a rubber joist protector which has likely made this worse. The contractors have agreed to change some of the joists (outer decking), but not all. They say the others are just surface splits and they aren't an issue. I assume they are trying to avoid taking the whole length of the decking up. I can't find any standards in regards to screws having to be centered in joists, and how wide a split has to be to be covered by AS. Any help much appreciated. Cheers The decking protector isn't a must have, I'm not a fan of it because it captures water under the boards. The timber can have some splitting but it shouldn't mean the screws are popping out. Can you upload some pics for reference?? MC Registered Building - Always happy to help where I can and simply loves the game. DM me if you need help in VIC. Re: Decking joists splitting 3Jan 08, 2020 10:14 pm MClark Thanks for the response. Please see examples. I’ve got the rubber joist protector on my other deck which has been down a few years. I had to take a few strips up to run an electric cable and it all looked like brand new underneath. No issues with water. What issues have you seen? I can’t see how it can trap water. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Decking joists splitting 4Jan 09, 2020 6:41 pm Yeh I can see what the issue is now, It doesn't look to be tradesman fault it is actually good he is coming back to do some parts. This is unfortunate that it has done this due to timber simply splitting, its a rather big job to pull the entire deck up to laminate a new joist. For the springing screws I would simple remove the ones currently in there and screw some new ones into the meat of the timber next to them to keep it down. Also hard to when you have big boards they move a lot! Especially when near water, they have at leasted used the correct screws for the job. MC Registered Building - Always happy to help where I can and simply loves the game. DM me if you need help in VIC. Re: Decking joists splitting 5Jan 10, 2020 8:50 am The joists have split as the screws are off center. Some of the joists have the screws 10mm from the edge of the joist. If it was just on the odd board it wouldn’t be an issue. But since it’s the entire way along the joist this is what has caused it to split. Do you know that the Australian Standards are? I can only find references to nails having to be centered and no mentions of screws. Also what are the standards around preventing wood from splitting and how big can a split be? Cheers Decking joists splitting 6Jan 10, 2020 10:28 pm Off centre screws has not caused this, it is probably due to a number of factors. Screws are best staggered as in not lined up as it is least likely to split the joist, it just looks worse. There is no standard but agree should be fixed, maybe the holes were underdrilled , hard to pin point exact cause. It looks much older than 6 months the coating looks like it is failing and the hoist has silvered, was the timber new when installed? Re: Decking joists splitting 7Jan 25, 2020 1:13 pm Sorry that was a typo. It’s almost a year and a half since installation. The problems started within a year of it being installed. Just having issues with the landscapers coming out to rectify. I took up one of the boards and the issue is worse than I thought. I’ve been trying to read the standards but there’s a few so not entirely sure which ones are specific. But it seems that screws have to be a minimum of 12.5mm from edge of boards, assuming this would be the same for joists, spacing has to be 8mm for wide boards. The average board spacing is about 4mm. Which is probably why they cupped so much pulling up the screws. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ 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 All, about to commence a bathroom renovation and need some advice on subfloor works. Current subfloor is hardwood T&G floorboards on 90x45 joists, but intention is to… 0 5834 Thanks for all replies. I just noticed now the pictures I added to post right on top of page were wrong. I attached pictures showing "current" and my "suggested" floor… 9 14635 |