Browse Forums Building A New House 1 Dec 21, 2019 9:08 am As per title, just wondering what major difference are there between the two. Is 300mm able to support more load Re: 240 vs 300mm joist 2Dec 22, 2019 7:51 am What are you supporting 3mm plywood? and what load does 3mm plywood carry other than self load? More info required Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: 240 vs 300mm joist 3Dec 22, 2019 12:22 pm StructuralBIMGuy What are you supporting 3mm plywood? and what load does 3mm plywood carry other than self load? More info required Tbh im not too sure. Its just with our house plans they are installing 240 joist, but im concerned it may not be strong enough if we decided to put heavier items upstairs. Then i saw another builder who was putting in 300mm and wondered if that would have been a stronger floor. Ive included a pic of our joist diagram Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: 240 vs 300mm joist 4Dec 22, 2019 1:01 pm Thanks for the info You will need more than a comment " Joist to framers Details?" for Construction/Building Certification I suggest you get copies of the certified engineering Beam & Joist Floor Plans before you commit 300mm spacing's may not be necessary, you may require deeper joists, what about deflection,etc,etc You don't want cost blow out surprises (re $ticker $hock) later on in the process when the engineering is submitted Hyspan Span Guide hth Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: 240 vs 300mm joist 5Dec 22, 2019 1:45 pm StructuralBIMGuy Thanks for the info You will need more than a comment " Joist to framers Details?" for Construction/Building Certification I suggest you get copies of the certified engineering Beam & Joist Floor Plans before you commit 300mm spacing's may not be necessary, you may require deeper joists, what about deflection,etc,etc You don't want cost blow out surprises (re $ticker $hock) later on in the process when the engineering is submitted Hyspan Span Guide hth Hi. Thanks for the reply Unfortunately at this stage the plans have already been submitted to council so its very unlikely i will make changes. Im more interested in learning the differences for when i build again. Stiffness, strength and load bearing capacity etc. Re: 240 vs 300mm joist 6Dec 22, 2019 7:29 pm They should have submitted proper certified engineering Plans to the Council along with the Building Applications (BA) the engineering also forms part of the contract documents do you not have copies? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Assuming you've modelled the TB8, TB10, TB12, TB2 & J1 joists/LVLs there, it appears as per drawing to me. There maybe should be an additional J1 between TB10 and T12 if… 3 31755 Seconded; we just used these last weekend to build a small deck. They worked perfectly as we have bluestone in the area where we wanted to build so digging down was not… 8 9053 1 10119 |