Pointing/Jointing Kandla grey riven sandstones - Best method ?

OK. The short version: jointing compound for wet weather, damp mix for dry weather. Details below. First dry mixes and wet slabs lead to massive cement staining which you'll have to remove with acid. This will lead in turn to damage and repointing. Drymixes in general result in weaker pointing which rapidly fails under pressure washing and general weathering. If you want a grey mortar, why use a white cement? This will give a pale pink, yellow or white mortar depending on your sand. Use ordinary cement with grey sand ( here in South Devon it's crushed quartz) commonly known as silver sand I think. Standard building grade is better than sharp. Rugby cement will give a dark grey mortar, and I'd go 4:1 for the mix. If you have bone dry slabs, use a damp mix I call crumb ( like your butter/ flour mix if you're making pastry) and push it in firmly with a jointing trowel. Be mindful of the mix drying out through the hours of work this will take, and make a series of small mixes. If you're really dextrous you can point with a stiff wet mix, but I tend to get in a mess with this- hidden puddles of water in the joints are annoying. Alternatively you can use a shop bought Jointing compound which can be used in wet weather but turns quickly in the sun. It isn't cheap- £35 will do around 12m2 on average, but it's clean and stain free. It's also with noting that you probably won't notice the pointing colour after a month of use and weathering, and also if you get an exact match for you kandla grey, you'll lose the definition of the slabs themselves and your beautiful sandstone patio will look like concrete screed! Think thats all. Pete

In my experience if you use yellow building sand and grey standard cement on that mix slightly moist then brush and point in after. Give a light spray after to help set and leave. Make sure you remove any excess from the slab to prevent staining. The resin looks pretty but if not correctly installed will easily pop and as soon as one bit goes it all tends to.

Mix normal building sand with cement at a ratio of 4 to 1 dry until mixed properly. Then just add a touch of water around quarter of a bucket to a full mixer load ie 16 parts sand to 4 parts cement and then carefully place between slabs into the joints and compressed with small finger. It's a very slow job but it's the cheap way of doing it. But must be mixed exactly the same amount each time or you will have colour variations. Buying the jointing compound is the answer in the long run but that also needs to be done properly or its a waste of money if not as it just comes loose

Completly do not rate Sika products or otherwise similar in this country on North West Atlantic island, great in the Med or dry sunny climes' but you still have to tool it in and having visited the sites where these products have been down for 3 seasons it has completely lost its original appearance and has the texture of a rubbery carpet underlay. A light sand, like Somerley (certainly not dried kiln as is non binding), a portland cement and a colour additive of which there are many. Mixed into a dough like texture.