An assessment is the value placed on a property by the town or city's assessor's office for the purpose of determining the property tax due. An entire town will be assessed during a 4-12 month period with values determined by a team of qualified assistants after viewing properties and interviewing owners.
We originally planned to lay the patio on a gravel and sand bed with the joints filled with sand. However, the guy doing the landscape design said we need to mortar the patio if we plan to use it for entertainment purposes, such as having a table and chairs on it.- Use a level religiously for the base layer and laying the rocks. -- Make sure you have a frame to contain the sand or it will seep out. -- Have a base layer of sand at least 2 deep. Flagstone rocks vary in thickness and you need the sand to adjust heights to get them all level.
Sandstone has two different kinds of material in it besides the sediment particles: matrix and cement. Matrix is the fine-grained stuff (silt and clay size) that was in the sediment along with the sand whereas cement is the mineral matter, introduced later, that binds the sediment into rock. Sandstone with a lot of matrix is called poorly sorted. If matrix amounts to more than 10 percent of the rock, it is called a wacke (wacky). A well-sorted sandstone (little matrix) with little cement is called an arenite. Another way to look at it is that wacke is dirty and arenite is clean.