Liquid Dpm Retrospectively Applied To A Concrete Balcony

I’m Andy Parkin Managing Director of the Multi-Award Winning Speed Screed. Thank you very much for your question, Catherine.

Your question is:

“I need to retrospectively apply a liquid DPM to a concrete balcony deck which has screed and paving installed. Can the liquid DPM be applied to the screed, or does it need to be applied to the concrete base?”

Watch Andy’s video to find out his answer:

Certainly, what you can do is apply it directly to the screed. In the original process, you could have used it on the concrete base and then put the screed on top.  I think it is just checking that the liquid DPM you are looking at is sufficient for the relative humidity of the screed that you are putting it onto. What you will find is that different liquid DPM’s perform at different relative humidities.

It is just making sure that it is going to be adequate to cover that with it being a balcony, as the relative humidity is likely to be quite high.  It is just checking definitely on that.

Another vital thing would be all about preparing to put the liquid DPM down. It has to get a key into the screed. That means that it needs to be free from contaminants, dirt, dust, etc.

With it being a screed, it may need some surface preparation, perhaps some grinding. If there is adhesive, etc on the surface, it may need some mechanical preparation. It is just making it ready to receive the liquid DPM so you get a good bond, and it doesn’t end up delaminating.

So long as you do the above, it should be fairly straightforward.

A typical liquid DPM, two-part epoxy resin, just make sure that the relative humidity capabilities of the liquid DPM match your individual circumstances.

Sometimes, if you’re looking at high relative humidity,  a two-coat liquid DPM system is often recommended.

If you need any other further help or assistance, we would be glad to help you with this.

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