Browse Forums General Discussion 1 Feb 28, 2014 8:27 am hey, my name is mathew, just have a question regarding the roof on an old dairy shed I am converting into a house. first off, half the roof has been taken off to change the pitch of the roof as it is too low at the lowest point. the issue i am having is, the original roof uses 70x45 hardwood timber at roughly 700 centres these are the rafters or joists, not 100% sure on the right word for it the battens? are 75x30 (height is 30) these are hardwood too the new half of the roof needs to be done in the same size wood so that i dont have different heights but in treated pine, the distance from the pitch is roughly 5metres and 10metres wide .The roof is being done in colourbond. will treated pine at 70x45 + 30 for the batten be strong enough to hold the roof if i do 350 centres? p.s I have put in a large beam 400 high x65 wide if this helps the situation thanks Re: questions regarding roof joists? 2Feb 28, 2014 9:25 am APPROXIMATE SPAN DETAILS (F7 Treated Pine) Pergola Beam (F7) Lightweight Sheet roofing only To support F7 Kiln Dried Treated Pine Rafters @ 600mm spacing Maximum Roof / Rafter length 3.0mtrs Timber size (mm) Span (mtrs) 70 x 45 1.4 90 x 45 1.5 140 x 45 2.3 190 x 45 2.9 240 x 45 3.5 290 x 45 n/a so i just came across this table, it sort of answers my question, except that i need to go roughly 5 metres, so if i go 200 centres would this be getting close or is there a minimum spacing you can go? example: a 70x45 treated pine with 600 mm spacing can go 1.4 metres, if i go 300mm spacing ill get 2.8, if i go 150mm spacing ill get 5.6metres? is that the right theory or not? 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 5820 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 14627 Houses have been framed on floor joists since settlement, chipboard flooring is only around for 50 years or so, so why would it not be satisfactory? However exercise skill… 3 16815 |