Browse Forums General Discussion 1 May 10, 2022 11:40 pm Hi everyone, Thanks for having me in your forum. I am currently 10m diameter hardwood octagon with a floating top hat. The main roof pitch is 20* The build is going well and the rafters are now fitted, and the next step is ceilings, purlins and roofing. We are hoping to expose the hardwood rafters so they are seen from below, One method i thought might work well would be to use an A grade plywood fixed to the top of the rafters, and then fix the battens (purlins) over the top of this. Constructing the roof in this fashion would be much faster, avoid the need for beading the join between the plywood and joists if it were fitted from the underside, and would allow for generous expansion joins over the rafters. My one concern is whether plywood is up the being sandwiched between a hardwood rafter and a hardwood purlin by a batten screw. I have tried to find numbers on the perpendicular compression strength of ply but i have not had much luck. I have seen this done on small cabins before but i am not sure if it is an 'approved' technique. Can anyone support of reject this construction method?? Thanks for your thoughts! Re: Exposed Joists and Plywood Ceiling Construction methods 3May 13, 2022 2:03 pm Looking at doing this too. My concern us the laying of the ply first over a greater distance before being supported by rafters. How do you overcome that? Provide temporary supports? At 3m this is a challenge. BTW your ply Willem easily handle the compression. Re: Exposed Joists and Plywood Ceiling Construction methods 4May 13, 2022 3:18 pm Ardo Looking at doing this too. My concern us the laying of the ply first over a greater distance before being supported by rafters. How do you overcome that? Provide temporary supports? At 3m this is a challenge. BTW your ply Willem easily handle the compression. Block of two storey townhouses requires painting on the roof. A brick parapet wall separates each unit and extends above the tiled roof. The parapet walls require sealing… 0 2818 Jimbo73 I would use heaps of adhesive on each sheet and screw rather than nail. use as many as you like cheers Simeon 1 3310 |