K-Rend Staining

[Sir Render]

Hi folks - any advice on how to get tannin stains from untreated timber out of K-Rend?

The K-Rend was applied in the last week onto the sides of planters and built-in benches. The benches have a cedar seat top and the tops of the planters have a cedar edging. The cedar is now starting to leach tannin where it comes into contact with the K-Rend. Not helped by the recent very wet weather.

The contractor plans to treat the timber when it has dried out, but in the meantime, we have staining and streaks on the render.

All I have been recommended so far is to try a very mild detergent with a soft brush or very low jet wash setting. I don't think this will shift it. Has anyone tried anything else with success?

 

[Jimbob9]

Rendit do some gear that you can coat it with that should help.

I've just used it on the advice of someone here to fix some rain damage and it worked a treat. Someone from Rendit used to post here but not seen them for a bit.

 

[Sir Render]

Rendit do some gear that you can coat it with that should help.

I've just used it on the advice of someone here to fix some rain damage and it worked a treat. Someone from Rendit used to post here but not seen them for a bit.

Thanks Jimbob9, yes I spoke to the advice line at Rendit yesterday and they were very helpful. Their MendRend Penetrating Acrylic sounds hopeful. My client is extremely particular and won't be happy with anything that changes the look of the render so I was just hoping there might be a way of getting the staining out of the K-Rend before resorting to the MendRend. Mind you, the Rendit guys seem confident that their product penetrates rather than sits on the surface, so this is probably the best option.

 

[Jgreenplastering]

Your more than like going to get staining in the near future if you've used it on the front of walls that have earth behind them and if you've taken it to floor and not put a drip bead in place with no render below.
Just a thought for you.

 

[Sir Render]

Your more than like going to get staining in the near future if you've used it on the front of walls that have earth behind them and if you've taken it to floor and not put a drip bead in place with no render below.
Just a thought for you.

That's a very good point. The planter is fibreglass lined, so hope we're OK on that one, but there's no drip bead at the base. They are on a timber deck on a roof terrace, set on bearers and there is a small gap between the rendered face and the decking. However, there is one area where the deck has been cut around the base of a planter and I can see some discolouration where there has been rain. Elsewhere we have full boards so am hoping this will be less of a problem. Would definitely spec a drip bead in the future. Thanks.