will this damage waterproof coating on rug?

I wash all my lightweight waterproof things (well everything I can get in my machine) in the washing machine with a little non bio detergent I have found (and read somewhere else on where too) that bio washing powerand fabric softener damage the waterproofing more quickly. I tend to then only reproof mine very occasionally and use a tent reproofing product and that works for me and saves a fortune in rug washing and reproofing.
 
I have washed my lightweight numerous times with normal excel gel and it hasn't lost any of it's waterproofing (as far as I can tell, I still have a dry coblet every night lol!) and that was before I even realised I shouldn't. So I think you'll be fine :) That was on 40 degress too as that's the lowest my old machine goes hehe.
 
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