The Brew Cabin

I have just laid a 22' x 24' paver patio and I am at the point where I need to do the jointing. We have a really bad problem with Burmuda grass creeping through flower beds, etc. and want to joint the patio so that we won't have this problem. It seems I had read somewhere once a long time ago about using a mixture of sand and mortar or sand and portland cement as a jointing material and then lightly spraying it with a garden hose. But I have not found any place that gives me instructions on how to do this. Plus, I'm concerned that we may end up with a haze of mortar on top of our pavers if we do this. I also have heard of possibly "sealing" the jointing sand so that it will not allow weeds/grass to grow in the cracks. Do you have a suggestion as to how we can joint our pavers so that grass will not grow in the cracks? Thanks.

I can't help you with the "Burmuda" grass - it's not something we have in Britain or Ireland, but using a sand/cement mixture to seal flexible block paving (which must be what you have on your patio if weeds are infiltrating the joints) is asking for trouble. You will get a mortar haze over the surface of the blocks, and the jointing will crack, eventually, allowing the weeds to get back in, so you'll have ruined your paving for a few months of respite.

In your part of the world (USA) polymeric sands are popularly used as joint fillers for flexible pavements and they do seem to reduce the incidence of weed colonisation, but I'm not convinced that they eliminate the problem completely. Two of the most popular products are Envirobond, which uses an organic component to 'set' the sand, and there's also Techni-seal which is a standard polymeric sand. I can't advise on sources or prices, as I don't keep info on N.American distributors, but you sjhould be able to glean further info from their respective websites.

In these soggy but occasionally pleasant isles, we would normally rely on a sealant to protect both the surface of the blocks from algae and liches, and the joints from mosses and grasses. Again, there's not a lot of info I can give you, as the sealants I usually recommend for British and Irish users are not generally available in your neck of the woods, but, if you take a look at ICPI, which is the US-ian trade website for flexible block paving, they might be able to point you in the right direction.

If you do follow this through, I'd love to hear how you get on, as I'm asked this question by US readers on an almost daily basis and I'd like to offer them something more than the few leads quoted above.

Just wanted to reply with what I choose to go with. I found a company in the U.S. called PaveTech http://www.pavetech.com/ , phone 1-800-728-3832. They make a product called SandLock that I purchased and it mixes with regular jointing sand right at the jobsite. It is activated by water and gels to bond the sand particals together and then once dry you have a good sealed joint. It seems to work well. We only had one problem, mostly our fault and it was unavoidable, since we were trying to get this done before the cold weather hit. The entire patio was dry, but one section of our patio had water still underneath the pavers (which we didn't realize) from a recent rain, so when we went to compact the area, the water and of course the SandLock oozed from the cracks and thats not a good thing. It will get on top of the pavers and leave a white residue. According to their brochure, it will require scrubbing to remove it, which we haven't attempted yet. So, my advice is to apply the SandLock after your patio has completely dried and also the sub-material underneath your pavers as well. I did contact ICPI and they also gave me other companies, TechiSeal(which you mentioned) and SureBond.

I'm familiar with PaveTech - in fact, I'm surprised I didn't mention them in my earlier post - but it's good to hear that you're happy with their product. We don't have PaveTech products in Britain and Ireland, but I'm sure your comments will be useful to other US-ian readers of the site. :)