Browse Forums Building A New House 1 Jun 29, 2017 7:11 pm Hi Homeone contributors I need some advice on our build. Our engineering team have come back with this.... "You’ll be pleased to hear that the engineer was able to design a steel beam over the Family/Meals/Kitchen that spans the entire distance, allowing for the wall at the end of the Kitchen bench to be removed but I need to make you aware that the engineer has estimated it will have 13mm of deflection once loaded, which means the centre of the beam will be approx 13mm lower than the ends but over the distance of the ceiling we believe you would not see this with the naked eye. " What do others think? Across a span of 9.5 metres is this reasonable and will it be noticeable? Thanks in advance Re: deflection in a ceiling beam.... how much is too much? 2Jun 29, 2017 7:34 pm I'd be surprised if anyone here can answer better that your engineer who has done the calculations - after all, that's what engineering is. For what it's worth though, I doubt you'll notice 13mm over 9500mm. Of course, you can always ask for a bigger beam, which will cost more. Re: deflection in a ceiling beam.... how much is too much? 3Jun 30, 2017 7:34 am Thanks - I trust the engineering, I just don't trust my fussy eye not to get annoyed at the deflection. I think however over that span I shouldn't notice it. Though it is always good to ask what others have experienced on the forum. Re: deflection in a ceiling beam.... how much is too much? 4Jun 30, 2017 8:52 am to see if you/d notice, get a sting line 9.5m long hung at approximately the same height as your ceiling then measure the drop in the centre so it's 13mm below the ceiling height and see if you notice. It's not a scientific method but should let you visualise the issue if you can get the line tight enough. Re: deflection in a ceiling beam.... how much is too much? 5Jun 30, 2017 9:44 am You 100% won't notice it. 13mm over 9.5m with such a large flat surface area will be impossible to see with the naked eye. Instagram blog: https://www.instagram.com/ourforevertonhome/ Re: deflection in a ceiling beam.... how much is too much? 6Jun 30, 2017 10:31 am pauldab to see if you/d notice, get a sting line 9.5m long hung at approximately the same height as your ceiling then measure the drop in the centre so it's 13mm below the ceiling height and see if you notice. It's not a scientific method but should let you visualise the issue if you can get the line tight enough. That is a very good suggestion. Re: deflection in a ceiling beam.... how much is too much? 7Jun 30, 2017 11:21 am arcadelt pauldab to see if you/d notice, get a sting line 9.5m long hung at approximately the same height as your ceiling then measure the drop in the centre so it's 13mm below the ceiling height and see if you notice. It's not a scientific method but should let you visualise the issue if you can get the line tight enough. That is a very good suggestion. It's actually a terrible suggestion, but I didn't want to be rude when I replied before. A single piece of string line will definitely be noticeable. We are talking about a ceiling here, a large flat surface area, which will be painted in a single colour not viewed at eye level. You will struggle to find a house build anywhere that has completely level ceilings. Load bearing supports, whether they are timber/LVL or steel, will always have flex. 13mm over 9.5m, will be impossible to notice. Instagram blog: https://www.instagram.com/ourforevertonhome/ Re: deflection in a ceiling beam.... how much is too much? 8Jun 30, 2017 6:21 pm pauldab to see if you/d notice, get a sting line 9.5m long hung at approximately the same height as your ceiling then measure the drop in the centre so it's 13mm below the ceiling height and see if you notice. It's not a scientific method but should let you visualise the issue if you can get the line tight enough. Re: deflection in a ceiling beam.... how much is too much? 9Jun 30, 2017 6:21 pm thanks pauldab I will do this - great suggestion Re: deflection in a ceiling beam.... how much is too much? 10Jun 30, 2017 6:27 pm lilbza - I really am thinking that I will not notice it over such a big span. However I appreciate all comment and advice that the good people of Homeone have taken the time to give. In our current 70 year old home the ceiling levels are all over the place and it troubles me a little so quite likely in the new place with minimal deflection I will not even notice. Re: deflection in a ceiling beam.... how much is too much? 13Jun 30, 2017 10:09 pm If you know it's there you will probably be conscious about it, however you can avoid it. Your beam can be prefabricated with a slight camber so when its fully loaded becomes perfectly straight. Alternatively, if your beams boxed in it will hide the deflection. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: deflection in a ceiling beam.... how much is too much? 14Jul 01, 2017 8:52 am aaaah that is a very interesting idea! I will talk to them about the prefabricated camber. thanks building expert. Re: deflection in a ceiling beam.... how much is too much? 15Aug 10, 2017 8:29 am WifeofHunza Your bedroom ceiling probably deflects that much & you don't even see it.. don't bother anything around span/500 is acceptable alternatives for decreasing deflection are too costly Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Hello everyone, After some suggestions and ideas about how to put a concrete path around the drop edge beam area on our new build. We are required to have a concrete path… 0 11041 The distance between my DEBs varies from 4.1m at the narrowest to 8.1m at the widest. 5 25922 |