Have you ever wondered how beautiful, long lasting patios are built in these harsh northeastern environments? It's all about the prep work!
With the extreme shifts in temperature, it's absolutely imperative that the site prep is executed to prevent frost heaving, erosion, and shifting. Using a paver patio as an example, it's not uncommon to see shifting between pavers, settling, or heaving after a couple of seasons. To ensure that doesn't occur, we prepare our sites in a uniform and consistent method using the following formula.
1) Excavate down to original sub-base. This could mean a shallow scrape of 6-8" or digging deeper down to untouched earth, from which we start laying out our process.
2) Once we've hit solid earth, we begin the rebuilding process, starting with layers of stone compacted every 6-8" using a plate compactor. This helps alleviate potential drainage issues, since stone is a very permeable substrate, and it ensures we are working on a solid and compacted base. Depending on how much we need to back fill, this would continue until we are 4" from the final base grade we are looking for.
3) Once we've established a compacted stone base, we dress it with 3" of "sure pac" or stone fines, which is then graded and compacted to allow for the patio to drain surface water into the areas we determine. This is typically set to slope at a pitch of 1/8" - 1/4" per foot and sloped to the areas we designate.
4) With our grades and slopes set, we add a final layer of clean sand which is compacted and double checked using our lasers that grade and slope are within spec.
5)At this point, the pavers can be laid out and installed.
6)Once the patio is installed, a final compaction occurs using a plate compactor and a special pad to prevent damage to the finished patio.
7) The optional final step is applying a sealer to the pavers, depending on the manufacturer's recommendations and client's preference.