Ratlines

[gill]

I'm installing RIgger's Apprentice ratlines between 1/4" stainless shrouds and have a bit of slippage when jumping down onto the wooden rungs. The shroud twists, unscrewing on the lashing, as the rung moves down. Is there an intermediate solution between lashing tight and serving the entire shroud? Tar on the end of the rung? Friction tape under the end of the rung? Another way to put additional tension on the tarred nylon? I used teak for the rungs and the endgrain provides no bite.