We have a large area (120smq) of Indian Stone paving where much of the pointing has failed. I've removed nearly all of the old pointing now and looking to replace it with something suitable.
The joints are very large and deep in places so probably need topping up with something first since most of the good products are quite expensive. Could they be topped up with a brush in sand/comment mix, leaving 20mm depth first?
We've been highly recommended Flowpoint, however are unable to get anyone familiar with the product to come and do it. Is this product suitable for a DIY'er or do we risk staining/ruining the patio? Perhaps it could be applied using a watering can straight into the joints (inveitables some will likely land on the paving) or is it better to just go for it and spread over with a squeegee ensuring to keep wet and hose off within the time period?
We could go with weatherpoint which seems rated on here but would be quite a bit more expensive I think.
It's the cleaning that is the 'make-or-break' factor with these products. You need to be sure you;d be able to get every last grain of mortar off the surface before it cures. This usually involves hiring-in a belt cleaner and then finishing with hand cleaning.
I wouldn't consider using a one-part resin/polymeric mortar - they just aren't good enough for modern deamnds, particularly power washing.
A two-part resin mortar would be ideal - even easier than a cementitious slurry to apply, far, far easier to clkean, much less roisk of staining....but they are damned expensive, 7 or 8 times the cost of a cementitious product.
So it comes down to whether you feel you have the skills to use a cementitious slurry cleanly or the budget to pay for a 2-part resin mortar.
Thanks Tony your reply is much appreciated. Going off the instructions for Flowpoint, it doesnt mention needing a belt cleaner, it seems to advise a sufficiently powered jetwash (although I'm yet to fathom how that doesn't blow the slurry back out the joints if it's gone off slightly but still soft enough to still wash off the paving).
Luckily we're in the process of removing a large section from the centre of the paving which we're going to turf which makes a nice area for washing off into.
I looked into the 2 part resins such as GftK’s vdw 850, however at £85 a tub we'd be looking at over £1500 for 18 tubs vs £360 for 18 bags of Flowpoint, which is hard to justify.
The idea of achieveing a clean finish with the power washer is.....errrr....pushing it a bit!
There's a critical few minutes when the mortar is sufficiently hard within the joints to withstand a VERY CAREFULLY applied pressure washer with a rotary head (Never the lance!) yet not fully bonded so it can be washeed clear of the surface of the paving. The advantage of the belt cleaner is that it runs across the joints, more-or-less replacing anything it removes, so you end up with a perfectly filled joint AND a properly cleaned surface.
I'd be reasonably confident that an experienced installer could achieve good results with a power washer, but I'd be scared shi....errr...witless as a DIYer!
Could you get a single bag of the flowpoint and try it out in a discreet corner somewhere before committing to the full load?
amazingly this is the exact same question i have, thanks for the pointer to this thread Tony. I must admit I'm leaning towards the 850 based upon this.
a2hgo I'm not sure when you're doing yours but you look a little further ahead than me. I'm going to order some 850 today and will let you know how it goes.
Thanks again Tony, you're right I am a little "hesitant" to say the least ha. Thats exactly my plan, to use one bag in one of the corners, perhaps where I've got the log store just off to the left of the photo and see how it goes before committing to the rest. I've got a volunteer to help with cleaning off so will also get plenty of sponges at the ready for manual cleaning if required.
@patioamat Looking at getting it done ASAP, just trying to find somewhere who will deliver me half a pallet as most only want to deliver a full one. Is the 850 working out much more for you cost wise?
How is the 850 an easier application process compared with the Flowpoint? Slower setting time?
850 simply washes off leaving almost no residue, and (assuming it's done correctly) any residue is a minimal film that weathers away in a couple of weeks. Anything that is accidentally left behind is either a grain or two of sand or the aforementioned virtually transparent film. Thorough cleaning usually takes 5-10 mins.
The cementitious mortars need repeated washing to persuade every last grain of cement to bugger off. Anything left behind is more likely to be highly visible (it's cement!) and getting rid of it is a nightmare because the usual 'fix' (acid) causes irreparable damage to the stone. Thorough cleaning takes 20-60 mins.
It's not that one product is superior to the other. They are both great products, but they have different skill requirements....and very different prices!
Just to update on this, Flowpoint went well, looks a million time’s better, it did leave a fine sheen on the slabs however this mostly came off with a subsequent jet wash.
