Grouting versus pointing. Is it best to point or grout flagstones?

This will help you decide how to fill in the joints of flagstone slabs on a path, driveway or patio.

Grouting is a term used for a wet mix of mortar to go in the joints of paving slabs. A sloppy mix is made up and spread over the slabs. It is moved over the surface usually with a squeegee (a rubber ended bar like window cleaners use. The squeegee spreads the grout over the paving slabs and a hose is used at the same time to keep the paving clean. Once the grout has fallen into the joints it is washed off using the squeegee and water spray. Then a layer of sharp sand is brushed over the area to soak up the remaining moisture and keep the flags free of concrete stains. Grouting flagstones is the preferred method as it allows for thin joints and gives a neat finish.

Pointing flagstone slabs is done using a semi dry mix. A trowel is used to place the mix in the joints and make a smooth surface to the mortar. This is the preferred choice when using uneven paving such as crazy paving (broken pieces of stone flags) or other natural stone slabs. Pointing can stain the pavers if the mix is too wet, if it is too dry you run the risk of it not setting properly.

In the battle of grouting versus pointing, the winner is definitely grouting for flat surfaces. It is not easy to do for first timers. The key is to make a mix of the right consistency so that it easily fills the joints but can be cleaned off the slabs surface too.

Other options for joints include small gravel for wide joints on a patio. This looks good at first but dirt will get mixed in too which will make the color darker and ensure a need for regular weed killer applications. Sand alone is a bad idea as it will wash out with rain and create a mess. Sand is only used for brick pavers (block paving) as the joints are extremely narrow so it doesn't wash out as easily. There are some ready made dry pointing products available but they don't seem to work very well and often crack.