Jointex or romex?

[Victoria]

Hello,
I'm hoping for some advice as I think I have a tricky one!

I need to re-joint a large patio (for my mum), consisting of v large irregular shaped slabs of slate. It was very overgrown with some serious 'weeds' (buddleia's, etc) which have now been cleared. The previous sand and cement jointing had failed and I suspect won't ever be tough enough.

The gaps range from practically nothing (i.e. <5mm) to around 10cm! Most stones are very large and heavy so won't move, but the odd ones are small and not fixed. They are all placed on earth, not a 'proper' base.

So...my questions!

- Will either Romex or Jointex do the job? Will they work on gaps filled with soil/some old mortar?
- Any other products recommended? Travis Perkins stock something called Pavetuf?
- What to do about moving smaller stones?
- What to do about v small gaps? (just accept won't work in those bits?)

It's been a nightmare to clear the weeds and I really want to get this right/not do again for a very long time! I suspect I won't be able to find a perfect solution, but something that will work for most of it would be great and I can cope with the odd patch that will need wedding, etc.

All advice appreciated.
Cheers
Victoria

[Victoria]

...should add it's a v low traffic area, definitely no vehicles!

I was also looking at Dansand no weed polymeric in Wickes - thoughts?

Thanks!

[Tony McC]

Dansand... should be re-named Don'tsand. It works for a few weeks/months and then turns into.....err....sand and comes out with surface scour and/or a power washer.

Regarding the other products, you need to understand the difference between 1-part and 2-part resin mortars. Jointex is a 1-part, and although it's a better-than-average 1-part, it's still not anywhere nears as tough or weed-resistant or power-washer-resistant as a good 2-part, such as Romex D1 (Romex do a 1-part by the name of 'Easy', just to confuse you).

A few years ago, 1-part products were seemingly miraculous and we all loved them, myself included, but the advances made with 2-part mortars means that I, at least, am now in a position where I only recommend 2-part products. They cost a few quid more, but, boy! Do you get value for money from that few extra quid! They are so bloody tough and resilient.

That's not to say there isn't a place for 1-part resin mortars. For low traffic, pedestrian areas, subject only to non-aggressive cleaning (nowt stronger than swilling down with soapy water and stiff brush) they represent an acceptable and lower-cost alternative.

Your project prsents two problems, though: Exceptionally narrow joints and then exceptionally wide joints. Straightaway, the 1-part products are highly unlikely to be suitable for wide joints (100mm or so) becuase they remain soft-ish and pliable even when cured, so they'll fail in time. And, apart from a couple of products I've seen in Germany, the 1-part products need a minimum 5mm joint width to stand any chance of surviving. There *are* 2-part narrow-joint resin mortars, which would work at 2mm joint width, but if you use these to fill 100mm wide gaps, it will be scarily expensive.

So: a compromise. I'd strongly suggest filling any joints in excess of, say, 25-30mm, with either a strong-ish (4:1) sand/cement mortar, or a grano mortar to keep costs realistic, and then a narrow joint 2-part resin mortar such as, say, VDW 815, for the <25mm joints. If you use a buff coloured resin mortar and silver sand for the sand/cement mortar, you'll get not-too-bad a colour match.....sort of. One that doesn't obviously clash, anyway!

[Victoria]

Hi Tony, thanks very much for your reply and the explanation of 1 part and 2 part resin mortars. It sounds like there's no perfect solution for this job but as long as I can get most of the joints successfully filled then I'll be happy. Good idea to fill in the larger gaps to keep costs down - I think I spotted a bag of Slablayer (or something like that?) in my mum's shed! Will that suffice to fill gaps and hold some of the loose stones in place before I use the final mortar?

I absolutely appreciate what you're saying about the 2 part mortar's being better. However cost may be prohibitive! It is a very low use area so I may just have to go with 1 part and cross fingers!

Thanks again

[matt_north]

Hi Victoria

Just to re-enforce Tony's point. There really is not much difference in price between Rompox Easy (1-part) and Rompox D1 (2-part). Because the slabs are laid straight on soil those weeds will be wanting to get through so the super tough 2-part would be a better bet.

Regards
Matt

[Victoria]

Hi Matt
Thanks for your message. Would you be able to recommend a supplier? I found Rompox 1 part and D1 on this site but the D1 is twice the price - https://lsd.co.uk/romex-r....ar-25kg I don't think my mum's budget will go that far as we're going to need at least 3 tubs.

Many thanks
Victoria

[Tony McC]

Try asking Cowley Stone - they are the main importer and distributor for Britain (Natural Stone Yard in Ireland).

I know the 2-part is more expensive, but it is *so* much better and, installed properly, will give years of troublefree service. I've seen streets in Germany where the original 2-part mortars were used over 20 years ago, and they're still working perfectly.

And that was the "old" formulation: the latest formulation is even better!

[Azpects]

Dansand... should be re-named Don'tsand. It works for a few weeks/months and then turns into.....err....sand and comes out with surface scour and/or a power washer.

Regarding the other products, you need to understand the difference between 1-part and 2-part resin mortars. Jointex is a 1-part, and although it's a better-than-average 1-part, it's still not anywhere nears as tough or weed-resistant or power-washer-resistant as a good 2-part, such as Romex D1 (Romex do a 1-part by the name of 'Easy', just to confuse you).

A few years ago, 1-part products were seemingly miraculous and we all loved them, myself included, but the advances made with 2-part mortars means that I, at least, am now in a position where I only recommend 2-part products. They cost a few quid more, but, boy! Do you get value for money from that few extra quid! They are so bloody tough and resilient.

That's not to say there isn't a place for 1-part resin mortars. For low traffic, pedestrian areas, subject only to non-aggressive cleaning (nowt stronger than swilling down with soapy water and stiff brush) they represent an acceptable and lower-cost alternative.

Your project prsents two problems, though: Exceptionally narrow joints and then exceptionally wide joints. Straightaway, the 1-part products are highly unlikely to be suitable for wide joints (100mm or so) becuase they remain soft-ish and pliable even when cured, so they'll fail in time. And, apart from a couple of products I've seen in Germany, the 1-part products need a minimum 5mm joint width to stand any chance of surviving. There *are* 2-part narrow-joint resin mortars, which would work at 2mm joint width, but if you use these to fill 100mm wide gaps, it will be scarily expensive.

So: a compromise. I'd strongly suggest filling any joints in excess of, say, 25-30mm, with either a strong-ish (4:1) sand/cement mortar, or a grano mortar to keep costs realistic, and then a narrow joint 2-part resin mortar such as, say, VDW 815, for the <25mm joints. If you use a buff coloured resin mortar and silver sand for the sand/cement mortar, you'll get not-too-bad a colour match.....sort of. One that doesn't obviously clash, anyway!

British made EASYJoint (1 part) can go down to 3mm widths, not that minimum width requirements will have any bearing on such a wide jointing job

Good luck with the job, we hope it goes well!