1554.1 2011 backing material Home › Forums › General › AS1554 Questions › 1554.1 2011 backing material This topic contains 1 reply, has 1,106 voices, and was last updated by DG 2 months, 1 week ago. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts February 6, 2018 at 5:55 am #1534 BallbearingMember DG,Code is correct as written.Fit-ups are not always perfect so that is why the code has tolerances.If you are using backing material it is quite easy to weld a 10.5 mm gap – it is not ideal but the code allows you to if required.Regards,BB February 6, 2018 at 9:59 am #1535 DGMember Can anyone confirm if tempory ceramic tiles are used as backing strip, does this mean that you use ( Table 5.2.2 allowable joint tolerances )Root gap with backing +6, – 1.5 mm. Our WPS has root opening 3.0mm to 4.5mm. If the above table is used in conjuction with the WPS the root gap can be up to 10.5mm. Our weld procedure is FCAW using 1.2mm wire. Big question is how do you complete your root run with 10.5mm gap? Or should the code be read as: Root gap without backing strip. (Table 5.2.2 allowable joint tolerances ) Root gap without backing strip + or – 1.5mm therefore max root gap would be 6mm,, this gap is ok. Any thoughts on which one is the correct interpretation Author Posts Viewing 2 posts - 1 through 2 (of 2 total) You must be logged in to reply to this topic.