Jason L Posted June 3, 2021 Share Posted June 3, 2021 Hi all, i been busy get my build underway, which has been a bit stressful. I have a question about battens, the construction - Timber frame, 9mm OSB vertical battens to create a ventilated cavity, 12mm render carrier board, and render on the outside. I had in my head all the time the battens to form the cavity are 38mm deep, but i have drawn all the drawings with them 25mm deep,... the question is, is a 25mm deep ventilated cavity ok behind the render carrier board, or does it have to be 38mm ? Thanks J Link to comment Share on other sites More sharing options...
Bitpipe Posted June 3, 2021 Share Posted June 3, 2021 25mm should be ok, how are you venting at the top? Ensure that the battens are fixed back to the structural members of the timber frame and not just pinned to the OSB. Your render company should have a detail that you can follow, even better is to get them to design the system and warranty it. Be very careful with your choice of renderboard - should be Knauf Aquapanel or similar. 1 Link to comment Share on other sites More sharing options...
Jason L Posted June 3, 2021 Author Share Posted June 3, 2021 3 minutes ago, Bitpipe said: 25mm should be ok, how are you venting at the top? Ensure that the battens are fixed back to the structural members of the timber frame and not just pinned to the OSB. Your render company should have a detail that you can follow, even better is to get them to design the system and warranty it. Be very careful with your choice of renderboard - should be Knauf Aquapanel or similar. thank you, its important as I'm butting up to an existing building and it needs to line through with it. Im planning on using STS construction board, and leave a gap at the top to ventilate it, and i guess it needs a gap anyway to allow the timber frame to shrink. ta Link to comment Share on other sites More sharing options...
nod Posted June 3, 2021 Share Posted June 3, 2021 If you are fixing your cement board to 25 mil Batons You will have to double up at the edges 25 will split You should always use 38 Link to comment Share on other sites More sharing options...
Jason L Posted June 3, 2021 Author Share Posted June 3, 2021 2 minutes ago, nod said: If you are fixing your cement board to 25 mil Batons You will have to double up at the edges 25 will split You should always use 38 i was thinking of using 50mm wide x 25 is that ok ? Link to comment Share on other sites More sharing options...
nod Posted June 3, 2021 Share Posted June 3, 2021 (edited) 8 minutes ago, Jason L said: i was thinking of using 50mm wide x 25 is that ok ? You can see what your render company says We are currently plasterboarding a TF site The spec is for 30 mil of the 45 to be in the timber and they are only holding Pb Cement board is very heavy 25 mil is asking a lot Edited June 3, 2021 by nod 1 Link to comment Share on other sites More sharing options...
Mr Punter Posted June 3, 2021 Share Posted June 3, 2021 25mm x 50mm battens is fairly standard. Stop them short at the top and bottom of openings to allow air to fully circulate. You will normally go round the outside of the openings with the same. 1 Link to comment Share on other sites More sharing options...
Jason L Posted June 3, 2021 Author Share Posted June 3, 2021 15 minutes ago, Mr Punter said: 25mm x 50mm battens is fairly standard. Stop them short at the top and bottom of openings to allow air to fully circulate. You will normally go round the outside of the openings with the same. thank you, ill have to get some start of the build pics up Link to comment Share on other sites More sharing options...
SuperJohnG Posted July 30, 2021 Share Posted July 30, 2021 I'm just about to buy battens for this for my SIPS with Knauf aquapanel. are C16 45x45mm battens ok for this? I thougth it woudl be 50 x 50 treated battens, but thinking it needs to be pressure treated wood and not just treated rough sawn? @nod can you help please as you seem to do it a lot. Link to comment Share on other sites More sharing options...
nod Posted July 30, 2021 Share Posted July 30, 2021 Yep John The 45s are fine 1 Link to comment Share on other sites More sharing options...
SuperJohnG Posted July 30, 2021 Share Posted July 30, 2021 2 hours ago, nod said: Yep John The 45s are fine Thanks for that. Link to comment Share on other sites More sharing options...
SuperJohnG Posted August 2, 2021 Share Posted August 2, 2021 On 30/07/2021 at 14:18, nod said: Yep John The 45s are fine In a strange turn, the Jewson rep told me the 45 x 45 C16 was suitable for outside, albeit wasn't sure as it was behind render board. Does anyone definitively know where I can find the answer if it can be normal 45 x 45 as above, or does it need to be 47 x 50mm treated (green) timber?. Any help appreciated. it's go tme going round in circles. Joiner reckons the green treated varies in thickness too much. Link to comment Share on other sites More sharing options...
nod Posted August 2, 2021 Share Posted August 2, 2021 They are better treated But it’s unlikely any moister will ever get past the R board and render Link to comment Share on other sites More sharing options...
SuperJohnG Posted August 2, 2021 Share Posted August 2, 2021 36 minutes ago, nod said: They are better treated But it’s unlikely any moister will ever get past the R board and render sorry that should have read 'unsuitable' above in my first sentence. I believe they are treated whitewood as per normal C16, but not like green treated. However I believe that the 47 x 50mm is so inconsistent that it's not worth using. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now