The Impact of Grout
Grout (and sometimes the lack of grout) has an amazing impact on the look and authenticity of stonework. Selecting the desired grout technique and grout color is often as important as selecting the stone. Here we will expore expert stone grout techniques that can be used in a variety of stone projects. Wether you call it thin stone veneer, faux stone veneer or artificial stone veneer, it always benefits from grout. There are three distinct stone grout techniques: Standard Joints (Raked), Dry- Stack Joints and Overgrout Joints.
Always have your mason prepare a mock-up of the grout finish you wish to use (standard, dry-stack or overgrout) prior to beginning the actual installation. Make sure you understand the intent of the finished joints, whether you are installing thin stone veneer or building an outdoor kitchen. All the stones shipped to the site should be placed face up over an area so a mental inventory of the sizes, shapes, and colors can take place. Many profiles require a rationing of certain stones throughout the entire process. Start at the corners and edges of the surfaces to be veneered and work inward. This will reduce the amount of cutting required to fit the stones.
- Adverse weather conditions affect manufactured stone during installation.
- Alternate corner colors and shapes. Avoid an "+" signs in the joints.
- Metal tools that strike the mortar breaks the skin which will cause moisture to rise and accelerate the drying time. It will also "polish" the grout.
Remember that selecting and applying the grout technique is as important as laying the stone. A grout style should be chosen before commencing installation. You can, and many times should, add color to the mortar to more closely match the stone. Care should be taken so that the color emulates a natural earthen sand color. Also, be aware of the geographic properties of different ingredients. Keep the face of the stone clean (unless you want a slurry finish.) Smeared mortar will permanently stain the stone.
- Don’t grout more than you can manage at one time.
- Joints can be tooled with specific masonry tools or with anything you find easy to use. If it works, use it!
- Don’t allow joints to fully harden. Mortar should be pliable and crumbly; not too wet and not too dry.
- Overgrout joints can be tooled (somewhat) earlier than raked joints.
- Using a grout bag is much easier than hand “tucking” the joints.
- Timing is everything.
Dry-stack joint stonework is accomplished by “dry” fitting each stone prior to installation. Each piece can be laid with virtually no joint. Even though you’ve used mortar to set the stone to the surface, when complete, the finished look will appear as though no mortar was used to install the stone. The intent of a dry-stack look is a tightly stacked stone appearance.
A standard joint (raked) is achieved by laying each stone roughly one finger width apart from each other, then grouting between each stone. The semi-dry mortar is later “raked” with a variety of tools ultimately achieving a consistent depth and giving it that distinctive raked out look.
Overgrout, an increasingly popular way to achieve an old-world look, is sometimes referred to as sack finish. Today, trowels, tuck pointers – even fingers – are used to achieve the overgrouted or sacked look. This technique tends to make the stonework appear rustic and aged. The grout overlaps the face of the stone, widening the joints and making them very irregular.