Romex in the wet

[richie_jones]

I`m still waiting for a spell of dry weather (at least 48hrs) which has to be on my days off(i work shifts), so that i can finish my patio by jointing with 4 tins of Romex easy.

I`ve just read with interest on the news page on this site, that the germans say its better to use the easy type in the wet. I`d like to know if anybody else has tried this and what results they had.
Or am I gonna have to be the guinea pig!!!

[worldofpaving]

Hi Rich,

I was interested by this so I had a look at the Romex TDS in German and they do indeed say that pre-wetting is good but they say clearly that no standing water should be in the joints to be filled.

I know from experience with resins and words used in TDS (not with Romex or this type of product) that it's such a bloody difficult area - how wet is wet, is your damp the same as my damp?

There are all sorts of acronyms like SSD (saturated, surface dry) to describe the actual amount of water around, my guess is that this is what they mean, wetted but without any standing water.

Usually in the UK the reason behind the question about being able to use a product on a wet surface is because it can be hard getting it dry and finding a dry day to apply so technically it can all become a bit of a minefield.

In your place I would want something a bit more definitive before speculating my time and money, I'm sure Romex would be delighted to advise.

Best,
WOP

[Tony McC]

The situation at the moment is that the UK/RoI licensee is carrying out tests to determine just how practical it is to use Romex Easy in the wet. I've seen no technical reports from Germany, only anecdotal evidence, and so I've advised the licensee to have the product tested, and preferably by an independent lab.

A colleague in the resins industry has told me that, if used with water, the resin used with Easy is likely to achieve comparatively lower compressive strengths, but this has not been proved by any independent testing.

However, the Spanish licensee is delighted with the results obtained by using the Romex Easy in the wet and has had no comebacks from the client or the client's customer. Bear in mind that Easy is targeted at patios, so there are no heavy dynamic loads that could compromise the product, so high compressive strength or high adhesion may not always be necessary.

[Davesmate]

You may be interested to know that almost any of the 'polymeric sand' based products that apply 'out of the vacuum sealed bag' will work in the wet or to be correct 'on a damp substrate with no standing water'. However there will be a drop in their compressive stregth - to somewhre between 2 and 8N/mm2 probably -dependent on the amount of water (it removes some of the polymer). This may or may not be an issue on a patio?
Tony will also probably remember a particulalry wet and windy day in January 2007 near Cologne when we saw the vdw 850 mortar from gftK demonstrated in a thunderstorm - with no problems! More expensive and much higher performance than a 'polymeric' but it works in the damp whatever the weather and with no loss of strength!.
There is also a new type of Polymeric resin being tested now that seems to be able to retain its stregth in the wet as well -- will let everybody know the results from NCC Streetscape in due course

[msh paving]

when gary from NCC came to demo gtfk he told me to use in the wet no problems and to dampen the surface first, he had a water sprayer with him MSH

[Davesmate]

Exactly it was the same vdw 850 mortar that Gary applied with you, which is an extremely cohesive 2 part epoxy resin bound mortar that 'flows' over or through the water into the joints and displaces any excess. The single pack polymeric sand products are much more sensitive and stregth reductions do occur - dependent on the amount of water. It is this problem that may well be overcome shortly by NCC Streetscape with a new formulation of their vdw 840 polymeric sand material - We will post the information in the Brew cabin as soon as testing is complete - hopefully next month!

[richie_jones]

Thanks for the input just looked at weather again and it gives rain till thursday so i`ll just keep waiting. I`m not happy with risking compromising the strengh of the finished joint as i`m allready struggling to achieve the recommended 30mm joint depth. Mostly 20 - 25mm .